Phylogeny of the tribe Aveneae (Pooideae, Poaceae) inferred from plastid trnT-F and nuclear ITS sequences

Abstract

New insights into evolutionary trends in the economically important oat tribe (Aveneae) are presented. Plastid trnT-F and nuclear ribosomal ITS sequences were used to reconstruct the phylogeny of the Aveneae-Poeae-Seslerieae complex (Pooideae, Poaceae) through Bayesian- and maximum parsimony-based analyses, separately and in combination. The plastid data identified a strongly supported core Aveneae lineage that separated from other former Aveneae and Poeae groups. Koeleriinae, Aveninae, and Agrostidinae emerged as the main groups of this core Aveneae, which also included other minor subgroups with uncertain relationships and a few former Poeae members. Several former Aveneae representatives were also placed in independent sublineages in Poeae. Seslerieae resolved as close allies of Poeae or Aveneae in the plastid and nuclear topologies, respectively. Because of the intermingling of some Aveneae and Seslerieae lineages in Poeae and vice versa, we propose to expand Poeae to include all the aforementioned lineages. This best reflects our current understanding of the phylogeny of these important temperate grasses and sheds light on their evolutionary history.

Full text

PHYLOGENY OF THE TRIBE AVENEAE (POOIDEAE,POACEAE)
INFERRED FROM PLASTID TRNT-F AND NUCLEAR ITS SEQUENCES
1
ALEJANDRO QUINTANAR,
2,4
SANTIAGO CASTROVIEJO,
2
AND PILAR CATALA
´N
3
2
Real Jardı´n Bota´nico de Madrid, CSIC, Madrid, Spain; and
3
Escuela Polite´cnica Superior de Huesca, Universidad de Zaragoza, Zaragoza, Spain
New insights into evolutionary trends in the economically important oat tribe (Aveneae) are presented. Plastid trnT-F and
nuclear ribosomal ITS sequences were used to reconstruct the phylogeny of the Aveneae–Poeae–Seslerieae complex (Pooideae,
Poaceae) through Bayesian- and maximum parsimony-based analyses, separately and in combination. The plastid data identified a
strongly supported core Aveneae lineage that separated from other former Aveneae and Poeae groups. Koeleriinae, Aveninae, and
Agrostidinae emerged as the main groups of this core Aveneae, which also included other minor subgroups with uncertain
relationships and a few former Poeae members. Several former Aveneae representatives were also placed in independent
sublineages in Poeae. Seslerieae resolved as close allies of Poeae or Aveneae in the plastid and nuclear topologies, respectively.
Because of the intermingling of some Aveneae and Seslerieae lineages in Poeae and vice versa, we propose to expand Poeae to
include all the aforementioned lineages. This best reflects our current understanding of the phylogeny of these important
temperate grasses and sheds light on their evolutionary history.
Key words: Aveneae; grass systematics and evolution; molecular phylogenetics; plastid and nuclear DNA sequence data;
Poeae; Pooideae; Seslerieae.
The oat tribe, Aveneae Dumort. (including Agrostideae
Dumort.), is the second largest tribe in subfamily Pooideae
Benth. and is one of the main groups of the grass family
[Poaceae (R. Br.) Barnhart]. It includes the economically
important oats, one of the most ancient food supplies for
humankind, and many of the most abundant grasses of
temperate ecosystems. It comprises about 57 genera and
1050 species (Clayton and Renvoize, 1986) that inhabit
temperate-to-arctic regions throughout the world (Stebbins,
1956; Stebbins and Crampton, 1961; Clayton, 1975, 1981;
MacFarlane and Watson, 1980, 1982; Clayton and Renvoize,
1986; MacFarlane, 1987; Watson and Dallwitz, 1992).
Traditionally, the Aveneae have been characterized by
morphologic traits related to their archtypical spikelet form of
long glumes (relative to spikelet length) and a tendency toward
a reduced number of flowers per spikelet, commonly 1, 2, or 2–
3 per spikelet. Other, apparently derived, features of Aveneae
include a soft endosperm with lipid energy reservoirs, which
presumably has adaptive value. Most of these features have
been interpreted as resulting from evolutionary trends that have
yielded highly specialized taxa (Clayton and Renvoize, 1986;
Ro¨ser, 1997).
Another remarkable feature of the tribe is the inclusion of a
large radiation of annual genera, mostly in the pan-Mediter-
ranean region, adapted to arid conditions and disturbance.
These annual species usually colonize ephemeral, often-
disturbed habitats, whereas most of the perennial taxa grow
in temperate grassland formations in natural, less-disturbed
areas (Clayton and Renvoize, 1986; Ro¨ser, 1997).
Aveneae classification and its taxonomical borders with its
sister tribe Poeae R. Br. have varied historically depending on
an author’s interpretations of the tribe’s morphologic hetero-
geneity; consequently, the adscription of many of its genera has
been problematical (Table 1). In modern classifications,
Aveneae have been separated from Poeae (and partly from
Seslerieae Koch) based on the floral traits cited (Tzvelev, 1976;
MacFarlane and Watson, 1982; Clayton and Renvoize, 1986;
Watson and Dallwitz, 1992). Tzvelev (1989), however, did not
recognize Aveneae but transferred their members to the large
tribe Poeae, although Phleeae Dumort. (including Phalarideae
Kunth) was separated from Poeae. An increasing number of
phylogenetic studies in recent decades have helped to clarify
evolutionary relationships within the subfamily Pooideae
(Soreng et al., 1990; Davis and Soreng, 1993; Nadot et al.,
1994; Hsiao et al., 1995; Catala´n et al., 1997; GPWG, 2001).
However, the details of the phylogeny of Aveneae have
remained largely unexplored. Most phylogenetic surveys
related to the avenoids have focused on particular genera, like
Helictotrichon (Grebenstein et al., 1998), Avena (Rodionov et
al., 2005), Arrhenatherum (S. Nisa et al., unpublished data),
and Deschampsia (Chiapella, 2007).
The first phylogenetic study with a large sampling of
Aveneae taxa was by Soreng and Davis (2000), who also
explored the relationships of its sister tribe Poeae. Their
combined analysis of plastid restriction site data and structural
data resulted in a consensus topology where the sister
divergence of the main Aveneae and Poeae lineages was
blurred by several admixtures of misplaced genera of the
opposite tribe. Genera traditionally classified in Poeae, such as
Briza,Chascolytrum Desv., Poidium Nees, and Torreyochloa
G. L. Church, were resolved as closely related to different
Aveneae lineages. Conversely, other genera formerly recog-
nized as Aveneae, like Avenula,Alopecurus,Holcus, and
Phleum, were nested within different clades of Poeae. Finally,
Soreng and Davis placed Aveneae within Poeae and recog-
1
Manuscript received 26 June 2006; revision accepted 11 July 2007.
The authors thank J. Mu¨ ller, R. Soreng, and C. Stace for valuable
comments and revision of an earlier version of the manuscript; L. A. Inda,
E. Pe´rez, M. Pimentel, and J. G. Segarra for their support and assistance in
the laboratory; and J. Mu¨ller, P. M. Peterson, M. Pimentel, M. Sequeira, R.
J. Soreng, and the curators of the JACA, MA, and US herbaria for
providing fresh samples and herbarium materials for the analyses. This
work was subsidized by the Ministerio de Ciencia y Tecnologı´a of Spain
(projects REN2003-02818/GLO and REN2002-04634-C05-05).
4
Author for correspondence (e-mail: quintanar@rjb.csic.es)
1554
American Journal of Botany 94(9): 1554–1569. 2007.

nized a series of subtribes of Aveneae that were later expanded
(Soreng et al., 2003). Past intertribal hybridization events were
advocated as a plausible explanation for the present existence
of certain Avenae taxa with Poeae plastid genomes and vice
versa, while most other cases were attributed to traditional
misclassifications (Soreng and Davis, 2000). The systematic
and evolutionary placement of the tribe Seslerieae with respect
to Aveneae and Poeae has also been debated (Table 1).
Seslerieae includes several genera characterized by their
strongly condensed inflorescences, often subtended by glume-
like bracts. The few molecular studies on single representatives
of Sesleria (Soreng and Davis, 2000; Catala´n et al., 2004;
Gillespie et al., 2006) indicated that this genus was close to
either Aveneae or Poeae, but the relationships were not
satisfactorily resolved. Duthieinae Potzal, which was subsumed
by Clayton and Renvoize (1986) under Aveneae but is
characterized by primitive traits such as havingthree lodicules
and three stigmas, was considered distantly related to Pooideae
but rather close to Arundinoideae Burmeist. (Watson and
Dallwitz, 1992) or Stipeae Dumort. (Soreng et al., 2003).
There is a current and increasing interest in the boundaries of
Aveneae and the evolutionary relationships among Aveneae
lineages and the closely allied Poeae and Seslerieae. Conse-
quently, we initiated an extended phylogenetic survey of these
groups using nuclear and plastid data. In the present study, we
include 42 genera of Aveneae (56% of its generic diversity
sensu Watson and Dallwitz, 1992) and three genera of
Seslerieae. Of the main Poeae lineages, 20 genera are included
(32% of the total). Our phylogenetic reconstructions are based
on analyses of DNA sequences from both the plastid trnT-F
region and the nuclear ribosomal ITS region (ITS1–5.8S-
ITS2). Use of nuclear and organellar phylogenies is recognized
as a reasonably sound approach for understanding the history
of groups that have presumably experienced reticulate
evolution (Soltis and Kuzoff, 1995). The value of sequences
of the plastid trnT-F region (trnT-L spacer and the useful trnL
intron–trnL 30exon–trnL-F spacer) for resolving phylogenetic
relationships was shown in the separation of the main lineages
of the large subtribes Loliinae Dumort. (Torrecilla et al., 2004;
Catala´n et al., 2004) and Poinae Dumort. (Brysting et al., 2004;
Hunter et al., 2004) of Poeae. The ITS region has also been
shown to be informative for phylogenetic inference in several
Aveneae (Helictotrichon, Grebenstein et al., 1998; Avena,
Rodionov et al., 2005; Deschampsia, Chiapella, 2007) and in
the subtribe Loliinae of Poeae (Charmet et al., 1997; Gaut et
al., 2000; Torrecilla and Catala´n, 2002; Torrecilla et al., 2004;
Catala´n et al., 2004), mostly because of its biparental
inheritance, the coupled effect of concerted evolution (Baldwin
et al., 1995), and a moderate rate of mutation (Torrecilla and
Catala´n, 2002) in temperate-climate grasses. By separate and
combined analysis of data from these two independent genomic
sources, we aim to reconstruct a phylogeny that can be used as
a baseline to interpret the evolutionary trends of the highly
relevant but inadequately explored oat tribe.
MATERIALS AND METHODS
Plant material—Sampling was designed to be representative of the
taxonomic/phenotypic diversity in the Aveneae tribe and included 105 species
and subspecies of 42 genera from the main lineages thought to belong to this
tribe (Watson and Dallwitz, 1992). Generic representatives of all subtribes of
Aveneae recognized by Tzvelev (1976) and by Clayton and Renvoize (1986)
(except Duthieinae) were sampled and incorporated into the analysis. Our
sampling includes representatives from subtribes Airinae Fr., Agrostidinae Fr.,
Alopecurinae Dumort., Anthoxanthinae A. Gray, Aveninae J. Presl, Beck-
manniinae Nevski, Gaudiniinae Holub, Holcinae Dumort., Koeleriinae Asch. &
Graebn., Miliinae Dumort., Phalaridinae Fr., Phleinae Dumort., and Ventena-
tinae Holub (Appendix). The poorly studied subtribe Koeleriinae was more
exhaustively sampled in our study with a wide representation of the Koeleria
and Trisetum taxa, as well as representatives of their supposedly allied genera
Avellinia, Dielsiochloa,Graphephorum, Rostraria, Sphenopholis, and Ven-
tenata. Sampling of the sister tribe Poeae (32 taxa, 20 genera) included
representatives of the main lineages of this group, i.e., the subtribes Loliinae
and its close allies Parapholiinae Caro, Cynosurinae Fr., and Dactylidinae
Stapf, and Poinae and its close ally Puccinelliinae Soreng & J. I. Davis, for
which new sequences were provided (Appendix), plus other lineages with an
unexpectedly close relation to Aveneae (Briza) or an uncertain attribution and
relationships (Anthochloa,Catabrosa,Cinna,Scolochloa, etc.) (Table 1).
Representatives of Seslerieae (Tzvelev, 1976) (Table 1) also were included in
our survey (three genera, four taxa; Appendix). Our systematic scheme follows
the tribal and subtribal circumscriptions proposed by Tzvelev (1976) and
Watson and Dallwitz (1992), and the generic ordering of Tutin et al. (1980).
DNA isolation, amplification, and sequencing—Leaf tissue from either
fresh silica-gel-dried materials or herbarium vouchers was ground to powder in
liquid nitrogen. Total DNA was isolated from each sample following the
procedures of the DNeasy Plant Mini Kit (Qiagen (Qiagen group, F.
Hoffmann—Spain Izasa S.A.)). The plastid trnT-F was amplified and
sequenced separately for the trnT-L and trnL-F subregions using external
primer pairs a-forward/b-reverse and c-forward/ f-reverse, respectively, as
described by Taberlet et al. (1991). The primer pair combination fern-forward/
f-reverse (Torrecilla et al., 2003) also was used for trnL-F amplification. Fifty-
microliter PCR reactions were prepared with 5 lL103buffer, 5 lL MgCl
2
(3
mM), 2 lL dNTPs (10 mM), 1 lL forward primer (50 lM), 1 lL reverse primer
(50 lM), 34.5 lL ddH
2
O, 0.5 lL Taq (1.5 u), and 1 lL DNA. Amplifications
were performed as follows: one denaturing cycle of 60 s at 948C; 30 cycles
including a 15-s denaturing at 948C, a 30-s annealing at 458C, and a 60-s
extension at 728C; followed by a termination step of 7 min at 728C. The ITS
region (ITS1–5.8S-ITS2) was amplified and sequenced using the external
primer pair combinations KRC-forward/ITS4-reverse and ITS1-forward/ITS4-
reverse (Torrecilla and Catala´ n, 2002). Fifty-microliter PCR reactions were
prepared in a reaction mix that consisted of 5 lL103buffer, 2 lL MgCl
2
(3
mM), 2.5 lL dNTPs (0.5 mM), 1.25 lL forward primer (50 lM), 1.25 lL
reverse primer (50 lM), 36.7 lL ddH
2
O, 0.3 lLTaq polymerase (1.5 u), and 1
lL DNA. Amplifications were carried out under the following conditions: one
denaturing cycle of 3 min at 948C; 35 cycles of a 1-min denaturing at 948C, a 1-
min annealing at 508C, and a 1-min extension at 728C; followed by a
termination step of 7 min at 728C. All PCR products were purified with the
QIAquick PCR Purification Kit (Qiagen). When more than one PCR band was
recovered, the suitable amplified band was separated on 1% agarose gels,
excised, and purified using the QIAquick Gel Extraction Kit (Qiagen). Clean
PCR products were sequenced with the BigDye Terminator v3.1 Cycle
Sequencing Kit (Applied Biosystems). Five-microliter sequencing reactions
were prepared with 1.5 lL53sequencing buffer, 1 lL sequencing mix, 1 lL
primer, 1.5 lL ddH2O, and 5 lL purified DNA. PCR was performed with one
denaturing cycle of 1 min at 958C; 99 cycles of 10-s denaturing at 958C, a 5-s
annealing at 508C, and a 4-s extension at 608C; then a termination step of 4 min
at 608C.
Sequence alignments and phylogenetic analyses—The trnT-F,trnL-F,
and ITS sequences were aligned separately using the program ClustalX,
version1.83 (Thompson et al., 1997). Manual alignment was further performed
on each data matrix with the aid of the program Se-Al v. 2.0a11 (Rambaud,
1996). The boundaries of the plastid trnL-F region and the nuclear ITS region
were determined according to those established by Catala´ n et al. (2004) for the
subtribe Loliinae, and the boundaries of the plastid trnT-F region were
determined according to those established by Mason-Gamer et al. (2002) for the
tribe Triticeae Dumort. The concatenated trnT-F and trnL-F data sets were
united into a single trnT-F plastid data matrix of taxa common to the two
separate data matrices. A total of 75 new ITS sequences (GenBank accession
numbers DQ336815–336834 and DQ539562–539616), 97 new trnT-L
(DQ336855–336880, DQ367404–367407, and DQ631481–631547), and 73
new trnL-F sequences (DQ336835–336854 and DQ631428–631480) were
generated for this study. Another 67 ITS and 26 trnL-F sequences were
September 2007] QUINTANAR ET AL.—PHYLOGENY OF TRIBE AVENEAE 1555

TABLE 1. Placement of the Aveneae and Seslerieae representatives included in our study in selected classification systems.
Ascherson and Graebner
(1898–1902) Maire et al. (1953) Prat (1960) Tzvelev (1976) Tutin et al. (1980)
Clayton and
Renvoize (1986)
Watson and
Dallwitz (1992) Soreng et al. (2003)
Aveneae Aveneae Aveneae Aveneae Aveneae Aveneae Aveneae Poeae
Airinae Airinae Aveninae Airinae
Aira Aira Aira Aira Aira Aira Aira Aira
Corynephorus Corynephorus Corynephorus Corynephorus Corynephorus Corynephorus Corynephorus
Deschampsia Deschampsia Deschampsia Deschampsia Deschampsia Deschampsia
Holcinae Holcinae
Holcus Holcus Holcus Holcus Holcus Holcus Holcus
Airopsis Airopsis Airopsis Airopsis Airopsis Airopsis
Periballia Periballia Periballia Periballia Periballia Periballia
Antinoria Antinoria Antinoria Antinoria
Aveninae Aveninae Aveninae
Arrhenatherum Arrhenatherum Arrhenatherum Arrhenatherum Arrhenatherum Arrhenatherum Arrhenatherum Arrhenatherum
Avena Avena Avena Avena Avena Avena Avena Avena
Avenula/
Helictotrichon
Avenula/
Helictotrichon
Avenula/
Helictotrichon
Avenula/
Helictotrichon
Avenula/
Helictotrichon
Avenula/
Helictotrichon
Avenula/
Helictotrichon
Helictotrichon
Pseudarrhena-
therum
Pseudarrhena-
therum
Pseudarrhena-
therum
Pseudarrhena-
therum
Corynephorus
Deschampsia
Holcus Gaudiniinae
Gaudinia Gaudinia Gaudinia Gaudinia Gaudinia Gaudinia Gaudinia Gaudinia
Avellinia Koeleriinae Avellinia Avellinia Avellinia
Koeleria Koeleria Koeleria Koeleria Koeleria Koeleria Koeleria
Rostraria Rostraria Rostraria Rostraria Rostraria Rostraria Rostraria
Trisetum Trisetum Trisetum Trisetum Trisetum Trisetum Trisetum Trisetum
Dielsiochloa Dielsiochloa Dielsiochloa
Graphephorum Graphephorum Graphephorum
Ventenatinae Sphenopholis Sphenopholis Sphenopholis
Ventenata Ventenata Ventenata Ventenata Ventenata Ventenata Ventenata Cinna
Dissanthelium
Agrostideae Agrostideae Agrostideae
Agrostidinae Agrostidinae Agrostidinae Alopecurinae Agrostidinae
Agrostis Agrostis Agrostis Agrostis Agrostis Agrostis Agrostis Agrostis
Ammophila Ammophila Ammophila Ammophila Ammophila Ammophila Ammophila
Apera Apera Apera Apera Apera Apera Apera
Calamagrostis Calamagrostis Calamagrostis Calamagrostis Calamagrostis Calamagrostis Calamagrostis
Gastridium Gastridium Gastridium Gastridium Gastridium Gastridium Gastridium Gastridium
Lagurus Lagurus Lagurus Lagurus Lagurus Lagurus Lagurus
Polypogon Polypogon Polypogon Polypogon Polypogon Polypogon Polypogon Polypogon
Zingeria Zingeria Zingeria
Triplachne Triplachne Triplachne Triplachne Triplachne
Chaetopogon Chaetopogon Chaetopogon Chaetopogon Chaetopogon Chaetopogon
Cinna Cinna Cinna Cinna
Deyeuxia Deyeuxia Deyeuxia
Miborinae Miborinae Ammochloa
Mibora Mibora Mibora Mibora Mibora Mibora Deschampsia
Phleeae Ventenata
Phleinae Phleinae Alopecurinae Alopecurinae
Alopecurus Alopecurus Alopecurus Alopecurus Alopecurus Alopecurus Alopecurus Alopecurus
Phleinae
Phleum Phleum Phleum Phleum Phleum Phleum Phleum Phleum
Chlorideae Isolated Beckmanniinae
Beckmannia Beckmannia Beckmannia Beckmannia Beckmannia Beckmannia
Phalarideae
(sub Panicoideae)
Phalarideae Phalarideae Phalarideae
Anthoxanthinae Phalaridinae Phalaridinae
Anthoxanthum Anthoxanthum Anthoxanthum Anthoxanthum Anthoxanthum Anthoxanthum Anthoxanthum Anthoxanthum
Hierochloe Hierochloe Hierochloe Hierochloe Hierochloe Hierochloe Hierochloe
Phalaridinae
Phalaris Phalaris Phalaris Phalaris Phalaris Phalaris Phalaris Phalaris
Stipeae Stipeae Stipeae Miliinae Milieae Stipeae Miliinae
Milium Milium Milium Milium Milium Milium Milium Milium
Zingeria Mibora
Poeae Poeae Poeae Poeae Poeae Poeae Poeae
Festucinae Festucinae Brizinae Brizinae
Briza Briza Briza Briza Briza Briza Briza Briza
Poinae
Catabrosa Catabrosa Catabrosa Catabrosa Catabrosa Catabrosa
1556 AMERICAN JOURNAL OF BOTANY [Vol. 94

retrieved from GenBank and included in the analyses. Of these, 10 partially
complete ITS sequences (ITS1 and ITS2 spacers) were used in our
phylogenetic survey, and the absent characters (5.8S gene) were coded as
missing data (Appendix). Gaps that were potentially informative were coded as
binary presence/absence characters and added to the respective sequence data
set for parsimony cladistic analysis.
Bayesian and cladistic analyses were made on both individual and combined
plastid trnT-F and nuclear ITS data sets using the programs MrBayes v. 3.0
(Huelsenbeck and Ronquist, 2002) and PAUP* v. 4.0 beta 10 (Swofford,
2002), respectively. Bayesian inference searches were performed independently
for each data set (trnT-F matrix, ITS matrix, and combined trnT-F þITS
matrix) with MrBayes, using the optimal nucleotide substitution model
previously selected for each case. This model was developed by calculating
likelihood ratios for 56 substitution models using the program Model Test v.
3.06 (Posada and Crandall, 1998). The three data sets generated the same
optimal general time-reversible model with a proportion of invariable sites
(GTRþGþI) and four gamma rate categories, which was imposed on the
subsequent analyses. The analysis of each separate data set was performed
through 1 000 000 generations by the Markov chain Monte Carlo (MCMC),
with three hot chains (hot temperature 0.2) and one cold chain, sampling every
100 generations and allowing the program to estimate the likelihood parameters
required. The log-likelihood scores of sample points were plotted against
generation time to estimate the number of generations needed to converge to a
stable equilibrium value (Huelsenbeck and Ronquist, 2002; Leache´ and Reeder,
2002). Sampled points from the generation previous to stationary were
discarded using the burn-in option of MrBayes. New Bayesian searches of
5 000 000 MCMC generations were conducted for each data set using the
topologies sampled from them to construct the respective 50% majority-rule
consensus topologies and calculate the posterior probability support (PPS) of
their lineages.
Parsimony-based analyses were conducted through two heuristic searches,
each aimed at recovering all possible equally shortest cladograms. An initial
search was completed with the following parameters: closest addition of taxa,
tree-bisection-reconstruction (TBR) branch swapping, and the Mulpars option
(multiple parsimony cladograms saved). The second search, which tried to find
other putatively shorter or equally parsimonious islands, consisted of 10 000
replicates of random-order-entry-starting cladograms with random addition of
taxa, tree-bisection-reconnection (TBR) branch swapping, and saving no more
than 10 cladograms of length equal to or less than 10 per replicate. All equally
parsimonious reconstructions obtained from the two searches were used to
compute the final strict consensus cladograms. Brachypodium distachyon (L.)
P. Beauv. (Brachypodieae Harz) and Secale cereale L. (Triticeae) were used as
outgroups; B. distachyon was used to root the cladograms. Branch support for
the optimal topologies found under these parsimony strategies was estimated
through 10 000 bootstrap replicates (Felsenstein, 1985) using the strategy of
DeBry and Olmstead (2000), which consisted of random addition of taxa and
TBR branch swapping, but saving fewer cladograms per replicate to reduce
computation time.
Conflicts between the topologies obtained from Bayesian and parsimony
searches were analyzed visually. Incongruences between plastid and nuclear
cladistic topologies were analyzed statistically using the nonparametric
Wilcoxon signed rank test (Templeton, 1983; Mason-Gamer and Kellogg,
1996). For this purpose, separate trnT-F and ITS matrices of 92 common taxa
were constructed from each data set, and a combined trnT-F/ITS matrix was
also created. The trnT-F/ITS combination of data sets were compared by
counting the number of steps required by each data set on its own optimal
topology (MP strict consensus) and on pairwise combinations with three
constraint topologies (the MP strict consensus and the 70% majority rule
bootstrap consensus obtained from the rival data set and the MP strict
consensus obtained from the combined data matrix). The number of steps
required in each case was calculated with PAUP* v. 4.0 beta 10, as indicated in
Mason-Gamer and Kellogg (1996). Significance values of the Wilcoxon signed
rank tests were obtained from the Vassatstats online application (http://
faculty.vassar.edu/lowry/wilcoxon.html), which provide two-tailed significance
values.
RESULTS
The trnT-F data set—The sequenced plastid trnT-F region
comprised 2455 aligned nucleotide positions, 1195 of them
corresponding to the trnT-L subregion and 1260 to the trnL-F
subregion. A total of 1065 positions were variable (43.3%, 496
in trnL-F and 569 in trnT-L), and 586 were potentially
parsimony informative (23.8%, 252 in trnL-F and 334 in trnT-
L). Informative gaps were frequent across the entire sequenced
trnT-F region, and a 30-nucleotide gap (positions 355–384)
was shared by the members of the Koeleriinae core: Avellinia,
Gaudinia,Koeleria,Rostraria,Trisetum, and Parafestuca.By
contrast, the trnL-F subregion had seven informative indels. A
large, 285-nucleotide gap (positions 219–503) was synapo-
morphic for the members of Koeleriinae (Avellinia,Gaudinia,
Graphephorum,Koeleria,Rostraria,Parafestuca,Sphenoph-
olis,andTrisetum) and Aveninae (Arrhenatherum,Avena, and
Helictotrichon subgenus Helictotrichon) lineages. Within
Koeleriinae, Gaudinia fragilis,Trisetum loeflingianum, and
T. ovatum, here named the Trisetum ovatum group, showed a
TABLE 1. Continued.
Ascherson and Graebner
(1898–1902) Maire et al. (1953) Prat (1960) Tzvelev (1976) Tutin et al. (1980)
Clayton and
Renvoize (1986)
Watson and
Dallwitz (1992) Soreng et al. (2003)
Colpodium Colpodium Colpodium Colpodium
Koeleriinae Dissanthelium Apera Gymnachne Gymnachne Gymnachne
Avellinia Avellinia Beckmannia Hellerochloa Hellerochloa
Koeleria Mibora Parafestuca Parafestuca
Cinninae Dissanthelium
Cinna Cinna
Scolochloeae Scolochloeae Scolochloinae
Scolochloa Scolochloa Scolochloa Scolochloa Scolochloa Scolochloa
Meliceae Meliceae
Anthochloa Anthochloa Anthochloa Anthochloa
Puccinellinae
Catabrosa Catabrosa
Pappophoreae Seslerieae Seslerieae Seslerieae
Sesleriinae Sesleriinae Sesleriinae
Oreochloa Oreochloa Oreochloa Oreochloa Oreochloa Oreochloa Oreochloa
Sesleria Sesleria Sesleria Sesleria Sesleria Sesleria Sesleria Sesleria
Ammochloinae
Ammochloa Ammochloa Ammochloa Ammochloa Ammochloa
Echinariinae
Echinaria Echinaria Echinaria Echinaria Echinaria Echinaria
September 2007] QUINTANAR ET AL.—PHYLOGENY OF TRIBE AVENEAE 1557

common nine-nucleotide indel (positions 1000–1008), whereas
Rostraria pumila, R. salzmannii, R. cristata, R. obtusiflora,
Trisetum gracile, and T. flavescens, here named the Trisetum
flavescens group, shared a large, 108-nucleotide gap (positions
897–1004). Another large gap of 188 nucleotides (positions
316–503) was synapomorphic for all representatives of Agro-
stidinae (Agrostis,Ammophila,Calamagrostis,Chaetopogon,
Gastridium,Polypogon, and Triplachne), as well as Briza,
Airopsis, and Gymnachne. This group also shared an additional
common five-nucleotide gap (positions 40–54). Holcus and
Deschampsia s.s. (D. cespitosa,D. setacea) each had genus-
specific gaps five nucleotides long (positions 235–239 and
164–168, respectively).
The Bayesian topologies reached a stable likelihood value
after the burn-in of 1000 phylograms. The 50% majority rule
consensus phylogram is shown in Fig. 1. Phylogenetic
relationships are relatively well resolved at the deepest
branches of the trnT-F topology. In the parsimony-based
analyses, the first heuristic search yielded 839 900 cladograms
that were 2353 steps long (L) and had a consistency index (CI)
(excluding uninformative characters) of 0.59 and retention
index (RI) of 0.76. The second search did not find any further
island of equally parsimonious cladograms. The strict consen-
sus of all these most parsimonious cladograms (not shown) was
compared with the Bayesian-based phylogram. Bayesian and
parsimony-based topologies were largely congruent and had
similar levels of support for the main lineages (Fig. 1). The
supertribal Aveneae-Poeae-Seslerieae complex was resolved as
monophyletic and highly supported (100% posterior probabil-
ity support [PPS]; 100% bootstrap support [BS]) when Secale
cereale and Brachypodium distachyon were used as outgroups.
Within this complex, there was an early divergence between a
highly supported ‘‘core Aveneae’’ lineage (100% PPS; 100%
BS) and a Poeae s.l. lineage (100% PPS; 95% BS), the latter
including the main Poeae subgroups plus many former
Aveneae groups (Fig. 1). Core Aveneae comprised five highly
supported subgroups: (1) Koeleriinae þAveninae þLagurus
(100% PPS; 100% BS), (2) Anthoxanthiinae (100% PPS;
100% BS), (3) Agrostidinae (100% PPS; 100% BS), (4)
Airopsis þBriza (100% PPS; 83% BS), and (5) Phalaris. In the
Bayesian phylogram, Phalaris was sister to a group formed by
the other lineages, which further split into the sister subgroups
(1)/(2) and (3)/(4), while Anthoxanthinae showed the sister
relationship of Anthoxanthum and Hierochloe; however, none
of those relationships, except that of the sister lineages
Agrostidinae/Airopsis þBriza (99% PPS; 80% BS), were well
supported (Fig. 1), and they collapsed into a polytomy in the
parsimony-based topology (not shown).
The Koeleriinae þAveninae þLagurus group had an initial
polytomy of Lagurus,Avena, and a series of remaining taxa
that diverged into successive weakly supported paraphyletic
Aveninae lineages (Helictotrichon s.s. and Arrhenatherum) and
a highly supported subgroup of Koeleriinae taxa (100% PPS;
82% BS) (Fig. 1). In the parsimony-based cladogram, the three
Aveninae genera with two species sampled were resolved as
monophyletic and sister to Koeleriinae but with low support
(not shown). Within the Koeleriinae lineage, the American
Graphephorum and Sphenopholis joined in a relatively well-
supported sublineage (100% PPS; 72% BS), sister to an
Eurasian sublineage (parsimony-based cladogram) or collapsed
with it (Bayesian phylogram). This group in turn diverged into
a highly supported Koeleria s.l. lineage (100% PPS; 90% BS)
and a less supported Trisetum s.l. lineage (96% PPS).
Gaudinia,Parafestuca, and some representatives of annual
Trisetum fell in the Koeleria s.l. subgroup, which included all
the Koeleria studied, whereas Avellinia and Rostraria were
embedded in the Trisetum s.l. subgroup that encompassed the
remaining samples of Trisetum. Little resolution was observed
in Koeleriinae, except for the strong relationships recovered for
the Trisetum ovatum group (Gaudinia fragilis, T. loeflingia-
num,T. ovatum; 100% PPS, 96% BS), the Trisetum flavescens
group (Rostraria spp., T. flavescens,T. gracile; 100% PPS,
100% BS), and the Koeleria splendens/T. hispidum lineage
(100% PPS; 86% BS). Agrostidinae had three early divergent
unresolved or poorly supported lineages (Gymnachne,Ammo-
phila,Calamagrostis) and a highly supported lineage (100%
BS) in which Triplachne/Gastridium (100% PPS; 97% BS)
were sister to the Agrostis group (100% PPS) (that included the
sister Polypogon and Chaetopogon, 100% PPS, 97% BS).
Briza joined with Airopsis in a highly supported group (100%
PPS; 83% BS).
Poeae s.l. diverged in two weakly supported lineages: Poinae
plus several former Aveneae þPuccinelliinae (78% PPS) and a
large, polytomic, and poorly supported group that included
Loliinae and its close allies, Seslerieae, and the rest of the
former Aveneae (89% PPS), such as Airinae, Deschampsia s.s.,
Holcus, and Avenula s.s. The first lineage diverged into two
groups: (1) a poorly supported group (55% PPS) with sister
relationships between Avenula pubescens and Milium, and
between Poa and the closely related Anthochloa and
Dissanthelium (100% PPS); (2) a group (100% PPS)
comprising Cinna,Ventenata, and Alopecurus. Puccinelliinae
were formed by the sister taxa Puccinellia and Catabrosa
(100% PPS; 100% BS). The highly supported Airinae (100%
PPS; 100% BS) comprised Aira, sister to a strong subgroup
composed of Corynephorus,Deschampsia maderensis,D.
flexuosa, and Periballia (100% PPS; 89% BS). The second
lineage encompassed many former Aveneae and Poeae:
Deschampsia s.s., Holcus, Seslerieae þMibora (98% PPS),
Parapholiinae/Cynosurinae (92% PPS), Dactylidinae þAmmo-
chloa (89% PPS; 59% BS), and Loliinae þAvenula (53% PPS).
There was a close and strongly supported relationship of the
avenoid Dielsiochloa to Hellerochloa and to representatives of
Festuca sect. Aulaxyper Dumort. (F. rubra group) (100% PPS;
97% BS). Weakly supported sister relationship of Ammochloa
to Dactylidinae (89% PPS) and the inclusion of Mibora in
Seslerieae (Sesleria,Oreochloa, and Echinaria), joined with
Oreochloa (100% PPS; 88% BS)were also evident.
ITS data set—The sequenced nuclear ITS region included
665 aligned nucleotide positions, of which 400 were variable
(60.1%, 162 in ITS1 and 204 in ITS2) and 303 were potentially
parsimony informative (45.5%, 130 in ITS1 and 154 in ITS2).
An eight-nucleotide gap in the ITS1 region (positions 55–62)
was considered synapomorphic for Koeleriinae (Gaudinia,
Koeleria,Graphephorum,Parafestuca,Rostraria,Sphenoph-
olis, and Trisetum).
The Bayesian topologies reached a stable likelihood value
after the burn-in of 1110 phylograms. The 50% majority rule
consensus phylogram is shown in Fig. 2. The first heuristic
search of our parsimony-based analyses yielded 510 800
cladograms of L¼2289, eight steps longer than the 25 equally
shortest cladograms found by the second search (L¼2281, CI
¼0.32, and RI ¼0.66). The strict consensus of all these most
parsimonious cladograms (not shown) was compared with the
Bayesian-based topology. Bayesian and parsimony-based
1558 AMERICAN JOURNAL OF BOTANY [Vol. 94

Fig. 1. The trnT-F search. The 50% majority rule consensus phylogram obtained by Bayesian inference. The scale represents 0.1 substitutions per site.
Values above branches indicate posterior probability support (PPS)/bootstrap support (BS) values of the groups. A dash means BS ,50%. The groups that
collapsed in the parsimony-based cladogram are marked with asterisks at their nodes. On the right, the black bar indicates those taxa formerly classified as
Aveneae.
September 2007] QUINTANAR ET AL.—PHYLOGENY OF TRIBE AVENEAE 1559

Fig. 2. ITS search. The 50% majority rule consensus phylogram obtained by Bayesian inference. The scale represents 0.1 substitutions per site. Values
above branches indicate posterior probability support (PPS)/bootstrap support (BS) values of the groups. A dash means BS ,50%. The groups that
collapsed in the parsimony-based cladogram are marked with asterisks at their nodes. On the right, the black bar indicates those taxa formerly classified as
Aveneae.
1560 AMERICAN JOURNAL OF BOTANY [Vol. 94

topologies were largely congruent (Fig. 2), although the
relationships, especially at deep nodes, generally resolved
better in the Bayesian topology. Despite the overall weakness
of the internal nodes of the ITS topology, the main lineages
recovered from the ITS data were largely congruent with those
recovered from the trnT-F data (Fig. 1). In the ITS topology,
the supertribe Aveneae–Poeae–Seslerieae also was monophy-
letic and well supported (100% PPS; 85% BS) when
Brachypodium,Secale, and Bromus were used as outgroups.
An early divergence separated Loliinae and allies (including
Dielsiochloa and Antinoria) (99% PPS; 67% BS) from all
remaining Aveneae–Poeae–Seslerieae taxa, which formed a
poorly supported group (52% PPS). Surprisingly, the avenoid
Antinoria was sister to a well-supported Loliinae þallies
(100% BS; 86% BS) in which Parapholiinae/Cynosurinae
(100% PPS; 99% BS) and Dactylidinae (100% PPS; 100% BS)
lineages intermingled with Festuca.Dielsiochloa also was
shown to be close to Festuca sect. Aulaxyper (F. rubra group),
joining in a highly supported subgroup with Hellerochloa
(100% PPS; 86% BS).
The large group of the remaining taxa collapsed into three
groups poorly supported by parsimony-based analyses. One of
these included the core Aveneae þSeslerieae þScolochloa
(100% PPS) and the Deschampsia s.s. þAvenula s.s. þ
Ammochloa (77% PPS) lineages, a second one the Airinae þ
Holcus lineages (99% PPS), and the third one the Poinae þ
allied lineages (100% PPS) (Fig. 2). Weak divergences and
polytomies were found at the deep nodes of the core Aveneae þ
SeslerieaeþScolochloa group. Koeleriinae (including Lagurus)
(100% PPS) and Aveninae (including Seslerieae) (65% PPS)
formed two groups, but the second was weakly supported.
Within the largely unresolved Koeleriinae, the Trisetum
flavescens group again was recovered (100% PPS), with
Rostraria subsp. (99% PPS, but excluding Rostraria cristata,
R. hispida, and R. obtusiflora) clearly separated from perennial
Trisetum (96% PPS). Within the Trisetum ovatum group, only
T. duforei and T. loeflingianum (100% PPS) had any
relationship. Koeleria pyramidata and K. dasyphylla were
linked (99% PPS). Aveninae resolved into two separate
lineages: a relatively well-supported Avena group (94% PPS;
77% BS) with sectional resolution as reported by Rodionov et
al. (2005), that formed a polytomy with the Seslerieae
representatives plus Mibora. In turn, Arrhenatherum,Helicto-
trichon, and Pseudarrhenatherum formed a group (93% PPS)
in which Helictotrichon was paraphyletic to a well-supported
subgroup (100% PPS) that also included Pseudarrhenatherum.
Within the better-sampled and strongly supported Anthoxan-
thinae (100% PPS; 100% BS), a polytomy is formed by
Hierochloe and Anthoxanthum lineages in the Bayesian
phylogram (Fig. 2). Agrostidinae formed a moderately
supported lineage (96% PPS), except for Calamagrostis and
Ammophila, which joined with Airopsis (54% PPS), and
Agrostis was paraphyletic and most of its sampled species
formed a group in which Chaetopogon was embedded (100%
PPS; 93% BS). A strong relationship between Triplachne and
Gastridium was again recovered by these data (100% PPS;
100% BS). Phalaris and Briza, collapsing at the base of the
group, and Scolochloa, as sister to the whole group, completed
this weak and large lineage. The Airinae lineage included
Deschampsia flexuosa, D. maderensis, Periballia, and Cor-
ynephorus (98% PPS; 60% BS). Poinae þPuccinellinae (100%
PPS) had a large basal polytomy of five lineages: (1) Poa þ
Anthochloa/Dissanthelium (94% PPS), which were weakly
grouped with Milium and Phleum (65% PPS); (2) Apera þ
Ventenata þAlopecurus þBeckmannia þCinna (91% PPS);
(3) Arctagrostis þAvenula pubescens (100% PPS); (4)
Colpodium þZingeria (100% PPS; 100% BS); and (5)
Puccinellinae (Sclerochloa,Puccinellia,andCatabrosa;
100% PPS; 98% BS).
Combined ITS/trnT-F data set—Most of the conflicts
affected relationships that were only weakly supported by one
set of data (Figs. 1 and 2). The main incongruences occurred in
the distinct placements of the Seslerieae þMibora group in the
trnT-F and ITS topologies. Sesleria,Oreochloa,Ammochloa,
and Mibora aligned within a highly supported Poeae s.l.
lineage in the plastid topology (Fig. 1) but within the poor to
moderately supported Aveneae þSeslerieae þDeschampsia þ
Avenula s.s. lineage in nuclear topology (Fig. 2). The Wilcoxon
signed rank tests showed significant incongruence between the
plastid and the nuclear topologies. The trnT-F data strongly
rejected the ITS strict consensus (P,0.001) and the 70% ITS
MR bootstrap consensus (P,0.001); similarly, the ITS data
strongly rejected the trnT-F strict consensus (P,0.001) and
the 70% trnT-F MR bootstrap consensus (P,0.001).
However, because of the scarce support recovered for many
of the relationships by the ITS data, their rejection by the trnT-
Fdata may not reflect strong conflict between them. The
combined topology, which is similar to the plastid one, was not
rejected by the plastid trnL-F-region data subset (P.0.26) but
was weakly rejected by the plastid trnT-L-region data subset
(0.036 ,P,0.073) and by the ITS data set (0.030 ,P,
0.060), thus indicating some discordances within the plastid
data set. While this test is useful for global comparisons, it is
also recognized to be problematic; topologies are likely to be
rejected topologies because of the presence of spurious nodes
in the rival constraint (Mason-Gamer and Kellogg, 1996). In
addition, the overall high congruence between the plastid and
nuclear Aveneae and Poeae lineages moved us to combine the
two matrices and to perform further phylogenetic analyses. The
combined trnT-F/ITS data set was made of 92 co-sequenced
accessions (Appendix). In the combined topologies, it was
clear that the large, highly structured, plastid DNA data set
overwhelmed the much smaller and less informative ITS data
set. Because of the scant information provided by the combined
topology, we did not show it here, referring to it only when
justified.
DISCUSSION
Aveneae core lineage—Although it had been suggested that
Aveneae were more advanced than Poeae (Clayton and
Renvoize, 1986), our analyses confirmed the insights of
Soreng and Davis (2000), which indicated that Aveneae and
Poeae were intermingled. Despite this admixture, our com-
bined and plastid analyses recovered two main groups
composed of mainly Aveneae and mainly Poeae taxa,
respectively (nuclear analyses did not render these two quite
definited groups but this should be carefully considered due to
the scarce support obtained for this topology at its deepest
nodes). The group primarily with Aveneae is named hereafter
the core Aveneae lineage, because it included representatives
of the most typical infratribal Aveneae taxa (Table 1),
Koeleriinae, Aveninae, and Agrostidinae, as well as minor
groups obscurely related to the previous groups, such as
September 2007] QUINTANAR ET AL.—PHYLOGENY OF TRIBE AVENEAE 1561

Lagurus, Anthoxanthinae, Airopsis,Phalaris, and Scolochloa
(Figs. 1 and 2). Additionally, it included a few Poeae
representatives such as Briza,Parafestuca, and Gymnachne
(Figs. 1 and 2), although some Poeae representatives
potentially related to this core Aveneae, such as Chascolytrum,
Poidium,andTorreyochloa, were not studied here (cf. Soreng
and Davis, 2000).
Koeleriinae and Lagurus—Trisetum has been considered the
ancestral lineage of Koeleriinae because of its less reduced
lemma (Clayton and Renvoize, 1986; Mosulishvili, 2000). The
lemma of Trisetum is three-awned with a main, often
geniculate, dorsal awn inserted from low down to near the
top, and two more or less developed, additional awnlets arising
from the lateral veins at the apex. The closely related perennial
Koeleria has muticous, mucronate, or apically or subapically
awned lemma.
Koeleriinae also includes ephemeral species adapted to dry,
open places from the Mediterranean to the western Himalayas.
They are placed either in Trisetaria Forssk., a name lately
fallen into disuse and applied to the annual species of Trisetum,
or in Rostraria, a small genus with straight, or sometimes
slightly curved, subapical awned lemmas. Additionally, the
annual Mediterranean genus Avellinia was placed in Trisetaria
(Clayton and Renvoize, 1986) or in Rostraria (Romero Zarco,
1996) because of similarities in its lemma. The American
Sphenopholis, separated from Trisetum by Scribner (1906)
because of its ovate glumes and florets disarticulating below
the glumes, and Graphephorum, with a lemma with an entire
apex and a reduced dorsal awn (subapical mucro) (Finot et al.,
2004, 2005a, b), were also considered to be related to Trisetum
(Clayton and Renvoize, 1986).
Koeleriinae were recovered in all our analyses, although they
were more strongly supported by the plastid data (cf. Figs. 1
and 2). Neither Koeleria nor Trisetum formed monophyletic
groups, but all Koeleria representatives were grouped into a
well-supported lineage, which also included several species of
Trisetum. Relationships within Koeleria spp. were not resolved
satisfactorily by the present analyses, and K. vallesiana and K.
crassipes appeared to be polyphyletic. Parafestuca, a mono-
typic endemic genus from Madeira traditionally included in the
Poeae (Alexeev, 1985; Clayton and Renvoize, 1986; Watson
and Dallwitz, 1992), was placed within this group (Figs. 1 and
2). Parafestuca was included in Koeleria, not only because of
its placement here, but also because its morphology is typical
of the genus Koeleria (Soreng et al., 2003; Quintanar et al.,
2006). This mostly perennial lineage also included the
Trisetum ovatum group, that comprised the annual T.
loeflingianum,T. ovatum, and the small genus Gaudinia,with
either strongly contracted panicles (Trisetum representatives) or
racemes of spikelets (Gaudinia). However, the circumscription
of this group was less clear in the ITS topology, which
recovered only a strong relationship for T. loeflingianum and T.
duforei (Fig. 2). Another Trisetum species, the perennial T.
hispidum, was unexpectedly linked with Koeleria splendens in
a relatively well-supported group (Figs. 1 and 2).
The remaining Trisetum taxa were included in a weakly
supported group that also included all the Rostraria taxa
studied and Avellinia (Fig. 1). The relationships of R. pumila
and R. salzmannii (plus R. litorea, Fig. 2) with the perennial T.
flavescens and T. gracile (plus T. turcicum in Fig. 2) were
corroborated by all the data sets, whereas the relationships of R.
cristata and R. obtusiflora with this last group were supported
only by plastid data (Fig. 1). This Trisetum flavescens group,
enlarged with Rostraria, corresponds with Trisetum sect.
Trisetum. This section was typified by T. flavescens and
characterized by more or less open, oval-to-pyramidal panicles
(Finot et al., 2004, 2005b). The close relationship found
between Trisetum and Rostraria agrees with earlier reports that
highlighted the strong resemblances between the lemma of
both genera (Hubbard, 1937; Holub, 1974; Jonsell, 1978).
Rostraria cristata,R. obtusiflora,R. hispida, and T. paniceum
were resolved by ITS data as relatives of the T. ovatum group,
but with little support (Fig. 2). Another Trisetum group, formed
by T. baregense,T. glaciale, and T. paniceum, was recovered
only by the combined data set (not shown) but not by separate
plastid and nuclear data. Trisetum glaciale was resolved as a
sister to the T. baregense–T. spicatum group in a moderately
supported lineage (Fig. 2). This group corresponds with
Trisetum sect. Trisetaera Asch. & Graebn., typified by T.
spicatum and characterized by dense, spiciform, and narrow
panicles (Finot et al., 2004, 2005b). Avellinia, only studied for
plastid data, remained in an unresolved placement within this
last group (Fig. 1). This genus might be an independent annual
derivation from a different perennial Trisetum line.
Graphephorum and Sphenopholis were placed within
Koeleriinae by all analyses (Figs. 1 and 2) and resolved as
sister lineages by the plastid and combined topologies (Fig. 1).
These results confirm the close relationships found between
Sphenopholis and Trisetum by Soreng and Davis (2000) and
the morphologic affinities between Graphephorum and Trise-
tum reported by Finot et al. (2005a). However, a larger
sampling of American Koeleria and Trisetum taxa is needed
before their systematics can be further assessed. Finally, this
Koeleriinae lineage can be distinguished by a set of
morphologic features, such as 2–5 florets per spikelet, a
relatively small spikelet, a keeled lemma (as opposed to more
or less rounded lemmas, as in Avellinia, Gaudinia, and some
Trisetum species), a poorly developed awn, glabrous ovary
(hairy in Gaudinia and in some Trisetum species, with an
apical appendage in Graphephorum), short hilum, and liquid
endosperm.
The Mediterranean genus Lagurus was part of a polytomy
that included either the Koeleriinae and Aveninae lineages by
plastid data (Fig. 1) or only Koeleriinae representatives by
nuclear data (Fig. 2). Lagurus has historically been included in
Agrostidinae (Table 1) based on its one-flowered spikelets, but
other general features of this monotypic genus, such as a
glabrous ovary, short hilum, and liquid endosperm, connect it
to Koeleriinae.
Aveninae—Genera of this subtribe have been characterized
traditionally by their long glumes, laterally compressed
spikelets with 1–2 (7) female fertile florets, and more or less
developed dorsal awns. Helictotrichon s.s. (excluding Avenula,
discussed later), traditionally considered as perennial oats,
separates from the mostly annual Avena based on its scabrid
and more strongly keeled glumes and on its linear-lanceolate
lodicules (Baum, 1968); however, the taxonomic boundaries
between Helictotrichon and other perennial Aveninae, such as
the European and Mediterranean Arrhenatherum with an either
hermaphroditic or female upper floret, and the Western
European Pseudarrhenatherum, with one incomplete floret
proximal to the hermaphroditic one, were never clear on the
basis of morphology.
Aveninae, including Avena,Arrhenatherum,Pseudarrhena-
1562 AMERICAN JOURNAL OF BOTANY [Vol. 94

therum,andHelictotrichon, were paraphyletic to Koeleriinae in
the plastid Bayesian phylogram (Fig. 1) but were united in a
weakly supported group sister to Koeleriinae in the parsimony-
based topologies and nuclear phylogram (Fig. 2), suggesting a
potential origin of Koeleriinae from within Aveninae. Helicto-
trichon, including most of the sampled taxa of this genus
(subgenus Helictotrichon), and Pseudarrhenatherum were
grouped, agreeing with the limited morphologic differentiation
found between them (Clayton and Renvoize, 1986). Helicto-
trichon subgenus Tricholemma Ro¨ser (H. jahandiezii), on the
other hand, was sister to Arrhenatherum (Fig. 2). This
Aveninae lineage can be characterized by a set of morphologic
features such as large spikelets, 1–7 florets per spikelet, hairy
ovary, long-linear hilum, grooved embryo, and mostly solid
endosperm.
Agrostidinae, Anthoxanthinae, and allies—Agrostidinae, the
third main subtribe of Aveneae, have been characterized
mainly by their small, one-flowered spikelets. They were
resolved as one of the main lineages of the core Aveneae (Figs.
1 and 2). The large genus Agrostis was resolved as para/
polyphyletic in the ITS analysis, with Chaetopogon nested in a
strongly supported Agrostis s.s. subgroup sister to A. truncatula
(Fig. 2). A. truncatula differs from other Agrostis in the
microstructure of the lemma and in its open and diffuse panicle
and was placed in subgenus Zingrostis by Romero Garcı´a et al.
(1988). The strong sister relationship recovered for the pan-
Mediterranean genera Triplachne and Gastridium in all
analyses corroborate previous ideas about their morphologic
affinities (Clayton and Renvoize, 1986). Calamagrostis and
Ammophila were placed in Agrostidinae (Fig. 1), but their
position was unresolved using nuclear data (Fig. 2). All these
genera have been included in Aveneae, except Gymnachne.
This South American genus has many florets (3–6) per spikelet
and one stamen per floret and has been placed in Poeae (Table
1) or in Poeae subtribe Brizinae (Soreng et al., 2003). This
Agrostidinae lineage has a set of morphologic features, such as
small spikelets, a single floret per spikelet (except Gym-
nachne), glabrous ovary, short hilum (long-linear in Ammo-
phila), and mostly solid endosperm (liquid in some Agrostis
and Polypogon species), that in conjunction separate Agros-
tidinae from both Koeleriinae and Aveninae.
Eurasian Briza traditionally have been classified as Poeae in
all morphology-based systems (Table 1) but were included
within Aveneae in molecular surveys (Soreng et al., 1990;
Hsiao et al., 1995; Soreng and Davis, 2000; see also Figs. 1 and
2). The small subapical awns in Briza and other closely related
Poeae, such as Chascolytrum and Poidium, were considered to
be a morphologic evidence of their affinities to Aveneae
(Soreng and Davis, 2000). The small genus Airopsis, which
was classified historically as Airinae (Maire et al., 1953; Albers
and Butzin, 1977) based on its putative similarity with Aira,
was placed with other representatives of the subtribe in the
vicinity of Agrostidinae and Briza. The broadly ovate,
ventricose glumes of monotypic Airopsis resemble those of
Briza, and this may reflect its true affinities. The plastid data
showed a sister relationship of Briza plus Airopsis to Agro-
stidinae, but this relationship was not supported by nuclear data
(Figs. 1 and 2).
Anthoxanthum,Hierochloe,andPhalaris, traditional mem-
bers of Anthoxanthinae (Table 1), have one distal female-fertile
floret per spikelet with proximal sterile—Anthoxanthum,
Phalaris—or male/neuter—Hierochloe—florets. Anthoxan-
thum and Hierochloe also share aromatic coumarin-scented
shoots, glabrous ovary, short hilum, small embryo, and hard
endosperm, whereas Phalaris differs because of its non-
aromatic shoots, small or large embryo, and a long-linear
hilum. The first two genera joined in a strongly supported
group sister to Koeleriinae þAveninae lineages (Figs. 1 and 2),
and nuclear data additionally showed a paraphyletic perennial
Hierochloe including a perennial-to-annual monophyletic
Anthoxanthum in the parsimony-based topology (not shown).
Anthoxanthinae included just these two genera; despite the
relationship between Anthoxanthum and Phalaris found by
Soreng and Davis (2000), our data clearly separated them from
Phalaris (Figs. 1 and 2). Phalaridiinae is restricted to Phalaris,
a genus of still uncertain relationships with respect to the
groups mentioned earlier, although the plastid topology
suggests that Phalaris is sister to all other core Aveneae
(Fig. 1).
On the other hand, Scolochloa, a wet-meadow grass from the
northern hemisphere that was classified in its own tribe
Scolochloeae Tzvelev or as a subtribe of Poeae (Table 1), was
sister to all core Aveneae lineages in the ITS phylogram (Fig.
2, not sampled in the plastid analyses). Its hairy ovary, long-
linear hilum, and hard endosperm may be plesiomorphic in
core Aveneae (cf. Baum, 1968).
Former Aveneae lineages related to the traditional Poeae
subtribes—Loliinae and its allied subtribes Parapholiinae,
Cynosurinae, and Dactylidinae, and Poinae and its allied
subtribe Puccinelliinae had poorly supported relationships to
many former Aveneae groups, and/or incorporated other genera
also classified as Aveneae (see Dielsiochloa and Loliinae)
(Figs. 1 and 2). Seslerieae were close to Aveninae (ITS, Fig. 2)
or sister to Parapholiinae/Cynosurinae (trnT-F, Fig. 1), or to the
whole large Poeae þformer Aveneae group in the combined
topologies.
Closest relatives of Poinae—A morphologically diverse
assemblage of Aveneae, such as Avenula pubescens,Alopecu-
rus,Apera,Beckmannia,Cinna, and Ventenata, formed a well-
supported group with Poa and relatives, although relationships
within this large group were unclear (Figs. 1 and 2). Avenula
pubescens represents an independent split from Helictotrichon
(Helictotrichon subgenus Pubavenastrum (Vierh.) Holub), and
it was not related to either the core Aveneae-allied Helicto-
trichon s.s. or the Loliinae-allied Avenula s.s. (discussed later).
This species is morpho-anatomically quite different from other
Avenula (Romero Zarco, 1984; Ro¨ser, 1989, 1997), although
its external appearance is that of a ‘‘ typical’’ Aveninae.
Grebenstein et al. (1998) and Soreng and Davis (2000; plastid
data alone) also recovered an isolated placement for this plant,
close to Alopecurus (Grebenstein et al., 1998; BS 75%). Here,
A. pubescens joined with Arctagrostis as part of a polytomy in
a poorly supported ITS-based group (Fig. 2). This latter genus,
which has sometimes been placed in Aveneae (Table 1), was
shown to be a close ally of Poa subg. Andinae in the more
detailed study of Poinae of Gillespie et al. (2006).
In the same assemblage we found Alopecurus and Phleum,
two genera distributed throughout the temperate northern
hemisphere and South America and traditionally placed in
Aveneae (Table 1) (Figs. 1 and 2), confirming previous
findings by Soreng and Davis (2000) and Gillespie et al.
(2006). Beckmannia, characterized by its long glumes and one-
or two-flowered spikelets and usually treated as Aveneae
September 2007] QUINTANAR ET AL.—PHYLOGENY OF TRIBE AVENEAE 1563

(Table 1), has also been considered to be related to Poeae
(Avdulov, 1931; Reeder, 1953) and was placed close to
Alopecurus in the ITS topology of Rodionov et al. (2005; BS
66%). The European-Mediterranean Apera, commonly includ-
ed in Agrostidinae (Table 1) because of its single-flowered
spikelet, was also placed in Poeae (Tutin et al., 1980). The
temperate Eurasian and American Cinna (Aveneae or Aveni-
nae, see Table 1), was resolved as a close relative of
Sphenopholis and Trisetum by Soreng and Davis (2000). Its
alignment with Poinae and relatives is consistent with its
recognition as subtribe Cinninae Caruel of Poeae. The
unexpected placement recovered for the small xerophytic
annual genus Ventenata contradicts traditional classifications in
which it was included in Avena (Reichenbach, 1830; Koch,
1854; Ledebour, 1853), Aveneae, or the Trisetum group
(Clayton and Renvoize, 1986) (Table 1). The nongaping paleas
and slightly grooved caryopsis (Eig, 1929) separate Ventenata
from Koeleriinae, and the phylogenetic relationships recovered
here could support its classification in a separate subtribe,
Ventenatinae.
Two small Eurasian genera, Colpodium and Zingeria,
formed a strongly supported lineage in this assemblage (Fig.
2). Despite previous attributions of Zingeria to Agrostidinae or
Aveneae (Table 1), this group was also reported by Rodionov
et al. (2005; BS 100%) in a sister placement to Alopecurus and
Beckmannia (BS 52%). Both genera have a single-flowered
spikelet, more or less awnless lemma, glabrous ovary, short
hilum, and a reduced base chromosome number, from 2 to 4.
The paleoartic genus Milium, with dorsiventrally compressed,
one-flowered spikelets and awnless lemma, has been placed in
either Aveneae, Stipeae Dumort., or its own tribe, Milieae Link
(Table 1). The position of Milium in our topologies confirms
the results of Soreng and Davis (2000) and Gillespie et al.
(2006), definitively places it in this heterogeneous group (Figs.
1 and 2), and is consistent with its treatment as a separate
subtribe. Finally, despite the placement of Anthochloa in
Aveneae (Stebbins and Crampton, 1961) or Meliceae (Clayton
and Renvoize, 1986), this monotypic genus, characterized by a
broadly expanded, flabellate lemma, and the pooid Dissanthe-
lium (Aveneae in Clayton and Renvoize, 1986), were found to
be sister to Poa, although with rather poor support (Figs. 1 and
2). This confirms their previous placement in Poeae (Soreng et
al., 2003) and findings by Gillespie et al. (2006) that places
these and other minor genera such as Austrofestuca and
Eremopoa with Poa.
Puccinelliinae were weakly supported as sister to Poinae and
relatives by the plastid data alone (Fig. 1) and included
Puccinellia,Catabrosa, and Sclerochloa. The close relation-
ship of the holarctic Puccinellia and the pan-Mediterranean
Sclerochloa in the nuclear topologies confirms earlier findings
by Choo et al. (1994) and Catala´n et al. (2004). The linking of
the helophytic to mesophytic Catabrosa, included in Meliceae
(Watson and Dallwitz, 1992), to this group also supports
previous findings (Soreng et al., 1990; Choo et al., 1994;
Gillespie et al., 2006). All these genera have (1) 2–10 florets
per spikelet, noncarinate lemma, glabrous ovary, short hilum,
and hard endosperm.
Closest relatives of Loliinae—Airinae, which traditionally
included the large, worldwide Deschampsia,Aira, and several
other small genera, are characterized by 2 (3) florets per
spikelet and usually straight or somewhat bent awns originating
from near the base to below the lemma apex. Deschampsia was
traditionally divided into two sections that were later
segregated into two independent genera, Deschampsia and
Avenella, based on differences in lodicule shape, root
histology, and spikelet architecture (Frey, 1999). The recent
phylogenetic study of Chiapella (2007), based on combined
nuclear and plastid data, has shown independent origins for
these two genera, a scenario also corroborated by our data
(Figs. 1 and 2). Airinae, excluding Deschampsia s.s., showed
the successive early divergences of Aira and Corynephorus and
included Avenella, represented here by the European De-
schampsia flexuosa and the Madeiran endemic D. maderensis
(Fig. 1). Plastid data suggest that Avenella is paraphyletic, the
Mediterranean annual Periballia being derived from within it
(Fig. 1). Despite the suggested affinities of Holcus and
Deschampsia (Clayton and Renvoize, 1986), our study did
not confirm a close relationship of Holcus to either
Deschampsia s.s. or Airinae, it being weakly resolved as sister
group to this last lineage only in nuclear analyses (Fig. 2). The
morphologic distinctness of Holcus, which is characterized by
its modified spikelets with a lower, awnless hermaphroditic
floret, an upper, straight-to-hooked, awned male floret, and
variable base chromosome number (n¼4, 7), supports its
placement in the monogeneric subtribe Holcinae. The place-
ments of Deschampsia s.s., Airinae, and Holcus, being part of a
polytomy with Loliinae and relatives (Deschampsia and
Holcus) or sister to them (Airinae) (Fig. 1), is not supported
by the nuclear data, that placed them sister to core Aveneae
(Deschampsia plus Avenula) or in polytomy with all of them
and Poinae and its relatives (Airinae and Holcus) (Fig. 2).
The separation of Helictotrichon s.s. (see Aveninae) from
Avenula (Helictotrichon subgenera Pratavenastrum (Vierh.)
Holub) has been controversial because of their general
similarity to Aveninae, although other morpho-anatomic
characters distinguish them (Kergue´len, 1975; Tutin et al.,
1980; Gervais, 1983). Our plastid analyses resolved Avenula
s.s. as sister lineage to Loliinae (Fig. 1), and including
Ammochloa, a small annual Mediterranean genus usually
treated as Poeae or Seslerieae (Table 1) and, more rarely, as
sister to Aveneae (MacFarlane, 1987). Nuclear data placed
Avenula sister to Deschampsia s.s. (Fig. 2), agreeing with
Grebenstein et al. (1998; 40% BS). This placement for Avenula
separate from the Aveneae core lineages agrees with the earlier
findings of Grebenstein et al. (1998) and Soreng and Davis
(2000) and corroborates the polyphyly of Helictotrichon s.l.
The plastid data placed Ammochloa as sister to Dactylidinae
but with poor support (Fig. 1). The main morphologic features
of Ammochloa, a condensed inflorescence, glabrous ovary,
short hilum and hard endosperm, are not those of Avenula but
are shared by the closest relatives of Loliinae (Parapholiinae,
Cynosurinae, and Dactylidinae). However, the high mutation
rate of the trnT-F region of Ammochloa, reflected by its long
branch (Fig. 1), may have disturbed the reconstruction of the
plastid phylogeny.
Festuca sect. Aulaxyper (F. rubra group) showed a strongly
supported sister relationship to a lineage formed by Dielsio-
chloa and the festucoid Hellerochloa, two restricted Central
and South American genera (Figs. 1 and 2). Dielsiochloa,a
small endemic genus restricted to Bolivia and Peru, tradition-
ally has been included in Aveneae (Table 1). Despite its long-
linear hilum and hard endosperm, it has been considered to be
related to Trisetum because its lemmas have straight dorsal
awns (Clayton and Renvoize, 1986). Finally, Antinoria, a small
Mediterranean genus with short hilum, glabrous ovary, and
1564 AMERICAN JOURNAL OF BOTANY [Vol. 94

characteristic of damp places, was considered as part of Airinae
by some authors (Albers and Butzin, 1977). Our results placed
it as a sister group to Loliinae, Parapholiinae, Cynosurinae, and
Dactylidinae (Fig. 2).
Misplaced lineages: Seslerieae and Mibora—The strongest
conflicts observed between plastid and nuclear topologies
affected the placements of the representatives of Seslerieae and
Mibora.Sesleria,Oreochloa, and Echinaria, three European
and Mediterranean genera characterized by their strongly
condensed inflorescences and traditionally classified in Sesler-
ieae (Table 1), along with Mibora, formed a moderately
supported group in both analyses (Figs. 1 and 2). Seslerieae
and Mibora linked with core Aveneae or with Poeae in the
nuclear and plastid topologies, respectively. This could indicate
a hybrid origin of the representatives of this lineage.
Morphology does not confirm the unexpectedly strong
relationship recovered between Mibora and Oreochloa using
plastid data (Fig. 1). The western Mediterranean–Atlantic
genus Mibora, characterized by its dwarf habit and single-
flowered spikelets, traditionally has been placed in either
Agrostidinae (sometimes in its own subtribe Miborinae Asch.
& Graebn.) or Alopecurinae (Table 1). Soreng and Davis
(2000) found Mibora resolved in Agrostidinae in their cladistic
analysis of structural data, but plastid data alone placed it in
Poeae; Soreng et al. (2003) tentatively placed it in Miliinae.
The high mutation rate of this annual lineage, reflected by its
long branches (Figs. 1 and 2), could have disturbed the
parsimony and Bayesian reconstructions. Further analyses of
larger samples of the Seslerieae group representatives are
required to clarify their relationships.
Evolutionary history of Aveneae, Poeae, and Seslerieae—
The presence of many groups, formerly placed in Aveneae, that
our analyses place in the neighborhood of Loliinae or Poinae
could be due to past hybridizations. Seslerieae, which have
pooid plastid and avenoid nuclear genomes, may have resulted
from past intertribal reticulation events that resulted in a new,
morphologically distinct lineage. In fact, extensive past
reticulation has been repeatedly invoked to explain the failure
to reconcile topologies recovered from nuclear and plastid data
in Pooideae (Davis and Soreng, 1993; Mason-Gamer and
Kellogg, 1996) and to explain the presence of pooid taxa with
an avenoid genome and vice versa (Soreng and Davis, 2000).
Although our nuclear ITS data do not strongly contradict our
plastid data, some former Aveneae, such as Deschampsia s.s.
and Avenula s.s., were placed sister to core Avenae by the
nuclear data (Fig. 2), despite the more distant relationship
provided by combined and plastid data (Fig. 1). This could
suggest potential topologic disturbances caused by the putative
paralogy of ITS ribotypes and homoplasy, a phenomenon that
often blurs ITS phylogenetic reconstructions, especially in
polyploid-rich groups (A
´lvarez and Wendel, 2003; Stace,
2005) such as some Aveneae. This scenario also could indicate
that the morphologic traits of many former Aveneae lineages
could be plesiomorphic or largely homoplasious. It also might
reflect the consequences of lineage sorting if the ancestral
Aveneae, Poeae, and Seslerieae diversified faster than the
fixation of gene copies in these lineages. However, reticulation
and lineage sorting scenarios are not easily differentiated a
priori (Kellogg et al., 1996), and both could have operated
together (Catala´n et al., 2004). Further analysis of other nuclear
single-copy genes and organellar genes might help to detect the
origin of each group and the nature of potential horizontal gene
transfer events, thus unraveling the evolutionary history of the
supertribal complex.
Large, species-rich lineages, such as Koeleriinae, Agro-
stidinae, Loliinae, Poinae, etc., with a strong internal structure
were generally distinguished from other small, less-diversified,
satellite lineages, such as Airinae, Alopecurus, Anthoxanthi-
nae, Antinoria, Avenula,Briza,Deschampsia,Holcus,Milium,
Phalaris,Phleum, and Scolochloa. Most of them are usually
sister groups to these large lineages groups in our topologies
(Figs. 1 and 2). The relatively high frequency of annual
radiations of species adapted to xeric environments in the large
groups contrasts with the predominant mesophytic-to-helo-
phytic perennial elements of the satellite groups. Soreng and
Davis (2000) speculated on the potential ancestry of the
helophytic Amphibromus,Torreyochloa, and Scolochloa, also
first divergent elements in their topologies, thus indicating a
temperate wetland origin for Aveneae and Poeae. Our results
seem to support that hypothesis, but some of those satellite
groups do not retain some of the characters considered
ancestral of the complex, i.e., long-linear hilum, hairy ovary,
multiflowered spikelets, multinerved glumes, and elaborate
awns (cf. Baum, 1968). This reinforces the idea of a widely
extended morphologic homoplasy within the complex.
Taxonomic recommendations—Systematically, the neat
separation of the Aveneae core lineages (Aveninae, Agros-
tidinae, Koeleriinae, Anthoxanthinae, and allies) from Poeae
and the remaining former Aveneae groups in the plastid
topology could support tribal status for the groups that form
that core. Certainly, acceptance of this tribal rank would be
consistent with most traditional classificatory proposals in
Pooideae (Table 1). However, many former Aveneae lineages
mentioned should be excluded from it, and the reconstituted
Aveneae would lack its distinctive morphologic features. An
alternative treatment could be the division of the complex into
three subtribes: (1) the Aveneae core groups, (2) Poinae and its
closest Aveneae relatives, and (3) Loliinae and its closest
Aveneae relatives. However, these groups have overall weak
support, especially by nuclear data, and they also lack
distinctive features. In accordance with the proposals of Soreng
and Davis (2000) and other authors (Tzvelev, 1989, pro parte;
GPWG, 2001; Soreng et al., 2003), we propose to accept an
enlarged Poeae that would include the former Aveneae, Poeae,
and Seslerieae lineages. This tribe can be split into different
subtribes, such as Aveninae, Koeleriinae, Agrostidinae,
Loliinae, Poinae, and others, as we probe its phylogenetic
structure more deeply. This way we can avoid taxonomic
conflicts between the phylogeny of these lineages and the
maintenance of older ranks that lack the morphologic attributes
that define them.
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APPENDIX. Voucher information and GenBank accession numbers for taxa used in this study. A dash indicates that the region was not sampled. Voucher
specimens belong to the following collections: AQ ¼Alejandro Quintanar collection; ARAN ¼Herbario de la Sociedad de Ciencias Aranzadi; CA ¼
Carlos Aedo collection; CN ¼Carmen Navarro collection; ES ¼Elvira Sauquillo collection; JACA ¼Herbario del Instituto Pirenaico de Ecologı´a de
Jaca; MA ¼Herbario del Real Jardı´n Bota´nico de Madrid; MERC ¼Herbario de la Universidad de Me´rida (Venezuela); MP ¼Manuel Pimentel
collection; MS ¼Miguel Sequeira collection; PC ¼Pilar Catala´ n collection; RS ¼Robert Soreng collection; SC ¼Santiago Castroviejo collection; UZ
¼Herbario de la Universidad de Zaragoza.
Taxon—GenBank accessions: ITS, trnL-F,trnT-L;Voucher specimen or data source.
Agrostis castellana Boiss. & Reut.—DQ539591, —, —; Spain:
Guadalajara (1997), MA 648799.A. magellanica Lam.—AY705883,
—, —; Gardner et al. (unpublished). A. stolonifera L.—DQ336815,
DQ336835, DQ336860; Spain: Huesca: Ordesa (1996), JACA 380196.
A. truncatula Parl. subsp. commista Castrov. & Charpin—DQ539592,
—, —; Spain: A Corun˜a, Montes do Pindo (1994), MA 581339.Aira
cupaniana Guss.—DQ631442, DQ631508; Spain: Jae´ n, La Carolina
(1988), JACA 348895.Airopsis tenella (Cav.) Coss. & Durand—
DQ539582, DQ631445, DQ631511; Portugal: Mogadouro (1997),
JACA 62597.Alopecurus geniculatus L.—DQ539571, DQ631433,
DQ631499; Spain: Guadalajara, El Cubillo de Uceda (1997), MA
642779.A. vaginatus (Willd.) Pall. ex Kunth—Z96920 & Z96921, —,
—;Grebensteinetal.(1998);Caucasus,Ossethi.Ammochloa
palaestina Boiss.—DQ539587, DQ631451, DQ631517; Spain:
September 2007] QUINTANAR ET AL.—PHYLOGENY OF TRIBE AVENEAE 1567

Almerı´a, Tabernas (1986), MA 478222.Ammophila arenaria (L.)
Link—DQ539590, DQ631456, DQ631522; Spain: A Corun˜ a, Carballo
(2004), MP s/n.Anthochloa lepidula Nees & Meyen—DQ539566,
DQ631430, DQ631496; Bolivia: Dpto. La Paz, Cumbre near La Paz
(2002), MA 721313.Anthoxanthum amarum Brot.—DQ539584,
DQ631448, DQ631514; Spain: Asturias, La Coba (1994), MA 539163.
A. aristatum Boiss.—DQ539585, DQ631449, DQ631515; Spain:
Pontevedra, Cabo Silleiro, ES s/n.Antinoria agrostidea (DC.) Parl.—
DQ539562, —, —; Spain: Zamora, Ta´bara (1996), MA 651156.Apera
interrupta (L.) P. Beauv.—DQ539570, —, —; Spain: Huesca (1988),
JACA 167088.Arrhenatherum elatius (L.) P. Beauv. ex J. & C. Presl
subsp. bulbosum (Willd.) Schu¨bl. & Martens—DQ336821,
DQ336841, DQ336866; Spain: Zaragoza (1999), JACA 128099.A.
calderae A. Hansen—DQ539596, DQ631462, DQ631528; Spain:
Canarias, Tenerife (2003), SC 17370.Avellinia michelii (Savi) Parl.—
—, DQ631465, DQ631531; Spain: Huesca, Monzo´n (1991), JACA
304591.Avena barbata Pott ex Link—AY093613, —, —; Moore and
Field (2005). A. clauda Durieu—AY522432, —, —; Rodionov et al.
(2005), Azerbaijan. A. eriantha Durieu—DQ336822, DQ336842,
DQ336867; Spain: Madrid, Chincho´n (2001); UZ JARL 032001.A.
hirtula Lag.—AY522435, —, —; Rodionov et al. (2005), Israel. A.
longiglumis Durieu—DQ539597, DQ631463, DQ631529; France:
Nice (1986), JACA 428986.A. macrostachya Balansa ex Coss. &
Durieu—AY522433, —, —; Rodionov et al. (2005), Algeria. A. pilosa
Scop.—AY530162, —, —; Rodionov et al. (2005), Azerbaijan. A.
sativa L.—AY520821, —, —; Rodionov et al. (2005), Germany. A.
ventricosa Balansa ex Coss.—AY522437, —, —; Rodionov et al.
(2005), Cyprus. Avenula albinervis (Boiss.) M. Laı´nz—AJ389123 &
AJ389124, —, —; Hemleben et al. (unpublished). A. bromoides
(Gouan) H. Scholz— —, DQ631459, DQ631525; Spain: Huesca,
Valfarta (1995), JACA 75295.A. bromoides—Z96844 & Z96845, —,
—; Grebenstein et al. (1998); France, Maury. A. compressa (Heuff.)
W. Sauer & H. Chmelitschek—Z96848 & Z96849, —, —;
Grebenstein et al. (1998); Turkey, Vil. Bolu. A. sulcata (Gay ex
Boissier) Dumort.—DQ539595, DQ631461, DQ631527; Spain:
Ciudad Real, Fuencaliente (1996), MA 597123.A. pratensis (L.)
Dumort.—Z96860 & Z96859, —, —; Grebenstein et al. (1998);
Caucasus, Pikritis Khevsureti. A. pubescens (Huds.) Dumort.— —,
DQ631460, DQ631526; Spain: Huesca, Cerler (1997), JACA 177197.
A. pubescens—Z96876 & Z96877, —, —; Grebenstein et al. (1998);
Caucasus, Ossethi.
Beckmannia eruciformis (L.) Host—AJ389163, —, —; Hemleben et al.
(unpublished). Brachypodium distachyon (L.) Beauv.—AF303399,
AF478500, DQ336855; Slovenia: Ljubljana, Torrecilla & Catala´n
(2002). Briza media L.—DQ539583, DQ631446, DQ631512; Spain:
Huesca: Panticosa (2000) PC s/n.B. minor L.—L36510, —, —; Hsiao
et al. (1995). Bromus tectorum L.—AJ608154, —, —; Blattner (2004).
Calamagrostis arundinacea (L.) Roth— —, DQ631455, DQ631521;
Spain: Navarra, Orbaitzeta (2001), ARAN 64564.C. epigejos (L.)
Roth—AJ306449, —, —; Jakob & Blattner (unpublished).
Chaetopogon fasciculatus (Link) Hayek—DQ539593, DQ631457,
DQ631523; Spain: Ca´ceres, Torrejo´n el Rubio (1983), MA 252874.
Catabrosa aquatica (L.) P. Beauv.—DQ539565, DQ631429,
DQ631495; Spain: Huesca, Sallent, Portalet (2004), UZ, PC s/n.
Cinna latifolia (Trevir. ex Go¨pp.) Griseb.—DQ539569, DQ631432,
DQ631498; Finland: South Ha¨me (1982), MA 363675.Colpodium
versicolor (Steven) Schmalh.—AY497472, —, —; Russia: Teberda,
Rodionov et al. (2005). Corynephorus canescens (L.) P. Beauv.—
DQ539578, DQ631440, DQ631506; Spain: Soria, Min˜ o de Medinaceli
(2004), AQ 1079.Cynosurus echinatus L.—AF532937, AF533031,
DQ631482; Spain: Soria, Monte Valonsadero, Catala´ n et al. (2004).
Dactylis glomerata L.—AF393013, AF533028, DQ631481; Spain:
Zaragoza, Moncayo, Torrecilla & Catala´n (2002). Deschampsia
antartica E. Desv.—AF521900, —, —; Corach et al. (unpublished).
D. cespitosa (L.) P. Beauv.—DQ539579, DQ631441, DQ631507;
Andorra, Pont de Capigol (2002), MA 700212.D. chapmanii Petrie—
AY752476, —, —; Gardner et al. (unpublished). D. flexuosa (L.)
Trin.—DQ539577, DQ631439, DQ631505; Andorra, Puerto de
Envalira (2002), MA 689503.D. maderensis (Hackel & Bornm.)
Buschm.—DQ539616, DQ631480, DQ631547; Portugal: Madeira: ca.
Pico Arieiro (2004), MS 4507.D. setacea (Huds.) Hack.—DQ539615,
DQ631479, DQ631546; Spain: Lugo, Vilalba (2000), MA 653850.D.
tenella Petrie—AY752475, —, —; Gardner et al. (unpublished).
Deyeuxia lacustris Edgar & Connor—AY705887, —, —; Gardner et
al. (unpublished). Dielsiochloa floribunda (Pilg.) Pilg.—DQ539563,
DQ631428, DQ631494; Bolivia: Dpto. La Paz, Cumbre near La Paz
(2002), MA 721312.Dissanthelium calycinum (J. Presl) Hitchc.—
DQ539567, DQ631431, DQ631497; Bolivia: Dpto. La Paz, Cumbre
near La Paz (2002), MA 721311.
Echinaria capitata (L.) Desf.— —, DQ631453, DQ631519; Spain:
Murcia, Moratalla (1997), MA 591692.
Festuca arundinacea (P. Beauv.) Schreber—AF519976, AY098995,
DQ367405; Spain: Lugo, La´ncara, Catala´n et al. (2004). F. frigida
(Hack.) K. Richt.—AF478481, AF478521, DQ631485; Spain:
Granada, Veleta, Catala´ n et al. (2004). F. borderei (Hack.) K.
Richt.—AF303403, AF478510, DQ631484; Spain: Huesca,
Vallibierna, Torrecilla & Catala´n (2002). F. fontqueri St.-Yves—
AF303404, AF533044, DQ631486; Morocco: Rif Mountains,
Torrecilla & Catala´ n (2002). F. k i n g i i (S. Watson) Cassidy—
AF303410, AY099004, DQ631487; USA: Colorado, Boulder Co,
Flat Irons, Catala´n et al. (2004). F. ovina L.—AF532959, AF533063,
DQ367406; Germany: Thu¨ringen, Saale-Holzland-Kreis, Catala´n et al.
(2004). F. paniculata (L.) Schinz. & Thell. subsp. paniculata—
AF303407, AF533046, DQ336858; France: Mont Aigoual, Torrecilla
&Catala´n (2002). F. r i v u l a r i s Boiss.—AF478475, AF478512,
DQ631488; Spain: Huesca, Cotiella, Torrecilla & Catala´ n (2002). F.
rubra L.—AY118088, AY118099, DQ336857; Switzerland: Valais,
Desses des Ferret, Catala´n et al. (2004). F. triflora Desf.—AF538362,
AF533052, DQ631483; Spain: Granada, Grazalema, Catala´ n et al.
(2004).
Gastridium ventricosum (Gouan) Schinz & Thell.—DQ336817,
DQ336837, DQ336862; Spain: Baleares, Mallorca, Puigpunyent
(1998), MA 618134.Gaudinia fragilis (L.) P. Beauv. (1)—
DQ539600, DQ631467, DQ631533; Spain: Ourense, O Barco de
Valdeorras (1989), MA 517046.G. fragilis (2)— —, DQ631478,
DQ631545; Spain: Ciudad Real, Fuencaliente (1996), MA 597178.
Graphephorum wolfii (Vasey) Vasey ex Coult.—DQ336823,
DQ336843, DQ336868; USA: California, Sierra Nevada (2004), RS
7416.Gymnachne koelerioides (Trin.) Parodi—DQ539594,
DQ631458, DQ631524; Chile (2001), RS 7035.
Helictotrichon convolutum (C. Presl) Henrard—Z96820 & Z96821, —,
—; Grebenstein et al. (1998); Dalmatia. H. desertorum (Less.) Pilg.—
AJ389095 & AJ389096, —, —; Hemleben et al. (unpublished). H.
filifolium (Lag.) Henrard—DQ336819, DQ336839, DQ336864;
Spain: Almerı´a (1997), MA 591453.H. jahandiezii (Litard. ex
Jahand. & Maire) Potztal—Z96840 & Z96841, —, —; Grebenstein
et al. (1998); Morocco, Moyen Atlas. H. sedenense (Clar. ex Lam &
DC.) Holub—DQ336820, DQ336840, DQ336865; Spain: Huesca
(1997), JACA 177297.Hellerochloa fragilis (Luces) Rauschert—
AF532960, AF533059, DQ631492; Venezuela: Me´rida, Pa´ramo de
Piedras Blancas, MERC, PC s/n.Hierochloe australis (Schrad.)
Roem. & Schult.— —, DQ631447, DQ631513; Finland: South Ha¨me
(1991), MA 696177.H. equiseta Zotov—AY705901, —, —; Gardner
et al. (unpublished). H. fusca Zotov—AY705902, —, —; Gardner et
al. (unpublished). H. novae-zelandiae Gand.—AY705900, —, —;
Gardner et al. (unpublished). Holcus gayanus Boiss.—DQ539574,
DQ631436, DQ631502; Spain: Asturias, Puente del Infierno (1998),
MA 655816.H. lanatus L.—DQ539575, DQ631437, DQ631503;
Italy: Abruzzo, Sorgente del Tirino (2002), MA 699215.
Koeleria albescens DC.—DQ336824, DQ336844, DQ336870; Spain: A
Corun˜a (2003), MA 706574.K. crassipes Lange (1)—DQ539603,
DQ631469, DQ631535; Spain: Madrid (2003), MA 706575.K.
crassipes (2)—DQ539602, —, —; Spain: Madrid (2003), MA
706580.K. dasyphylla Willk.—DQ336825, DQ336845, DQ336871;
Spain: Ca´diz (1993), MA 526298.K. macrantha (Ledeb.) Schult.—
DQ336826, DQ336846, DQ336872; Spain: Huesca (2001), JACA
264664.K. pyramidata (Lam.) P. Beauv.—DQ336827, DQ336847,
DQ336873; Spain: Lleida (1999), JACA 147297.K. splendens C.
1568 AMERICAN JOURNAL OF BOTANY [Vol. 94

Presl—DQ336828, DQ336848, DQ336874; Italy (2000), MA 645409.
K. vallesiana (Honck.) Gaudin subsp. vallesiana (1)—DQ336829,
DQ336849, DQ336875; Spain: Madrid (2003), MA 706578.K.
vallesiana subsp. vallesiana (2)—DQ539604, DQ631470,
DQ631536; Spain: Palencia (1995), MA 560050.K. vallesiana
subsp. castellana (Boiss. & Reut.) Domin—DQ539601, DQ631468,
DQ631534; Spain: Madrid, Aranjuez (2004), AQ 997.
Lagurus ovatus L.—DQ539598, DQ631464, DQ631530; Spain: Almerı´a,
Cuevas del Almanzora (1998), MA 613465.Lamarckia aurea (L.)
Moench—AF532935, AF533029, DQ631490; Spain: Zaragoza,
Puente Almozara (2000), Catala´ n et al. (2004). Lolium perenne
L.—AF303401, AF478504, DQ367404; England (cv.), Torrecilla &
Catala´n (2002).
Mibora minima (L.) Desv.—DQ539589, DQ631454, DQ631520; Spain:
Madrid, Boadilla del Monte (2004), AQ 977.Milium effusum L.—
DQ539573, DQ631435, DQ631501; Finland: Lapponia sompiensis,
Sodankyla¨ (1996), JACA 199998.
Oreochloa disticha (Wulfen) Link—DQ539588, DQ631452, DQ631518;
Spain: Palencia, Cervera de Pisuerga (1997), MA 590914.
Parafestuca albida (Lowe) E.B. Alexeev—AF532930, AF533022,
DQ336869; Portugal: Madeira, Pico do Arieiro (2001), MA 721307.
Parapholis incurva (L.) C.E. Hubb.—AF532942, AF533036,
DQ631491; Spain: Zaragoza, Vedado de Pen˜aflor, Catala´n et al.
(2004). Periballia involucrata (Cav.) Janka—DQ539576, DQ631438,
DQ631504; Spain: Ciudad Real, Solana del Pino (1996), MA 597226.
Phalaris canariensis L.—DQ539580, DQ631443, DQ631509; Spain:
Huesca, Cuarte (cultivated), AQ 1429.P. coerulescens Desf.—
DQ539581, DQ631444, DQ631510; Spain: Ca´ceres, Malpartida de
Plasencia (2001), MP s/n.P. truncata Guss. ex Bertol.—L36522, —,
—; Hsiao et al. (1995). Phleum phleoides (L.) H. Karst.—AF498396,
—, —; Subbotin et al. (2004). P. pratense L. subsp. bertolonii (DC.)
Bornm.—DQ539568, —, —; Spain: Ciudad Real, Fuencaliente
(1996), MA 597217.Poa annua L.—AF521901, —, —; Corach et
al. (unpublished). P. i n f i r m a Kunth—AF393012, AF488773,
DQ367407; Spain: Zaragoza, La Jota, Torrecilla & Catala´ n (2002).
Polypogon maritimus Willd.—DQ336818, DQ336838, DQ336863;
Spain: Ciudad Real, Valverde (1999), MA 648807.
Pseudarrhenatherum longifolium (Thore) Rouy—AJ389161 &
AJ389162, —, —; Hemleben et al. (unpublished). Puccinellia
distans (L.) Parl.—AF532934, AF533024, DQ336859; Spain:
Navarra, Lazagurrı´a, Catala´n et al. (2004).
Rostraria cristata (L.) Tzvelev—DQ336833, DQ336853, DQ336879;
Spain: Tarragona (1999), JACA 630099.R. hispida (Savi) Dogan—
DQ539610, —, —; Spain: Sevilla (1977), MA 278005.R. litorea (All.)
Holub—DQ539611, —, —; France: Corse (1981), MA 392462.R.
obtusiflora (Boiss.) Holub—DQ539612, DQ631475, DQ631541;
Israel (1989), MA 498402.R. pumila (Desf.) Tzvelev—DQ336834,
DQ336854, DQ336880; Spain: Almerı´a (1998), MA 613459.R.
salzmannii (Boiss. & Reut.) Holub—DQ539613, DQ631476,
DQ631542; Tunisia (1999), MA 693894.
Secale cereale L.—AF303400, AF478501, DQ336856; USA: Torrecilla
& Catala´n (2002). Sesleria argentea (Savi) Savi—AF532931,
AF533030, DQ631544; Spain: Navarra, Araxes, Catala´ n et al.
(2004). S. coerulea (L.) Scop.—DQ539586, DQ631450,
DQ6315106; Spain: Huesca, Pue´rtolas (2001), JACA 266634.
Sclerochloa. dura (L.) P. Beauv.—AF532933, AF533023, —;
Spain: Segovia, Sepu´lveda, Catala´n et al. (2004). Scolochloa
festucacea (Willd.) Link—DQ539564, —, —; Finland: Joutsa
(1992), MA 692842.Sphenopholis intermedia (Rydb.) Rydb.—
DQ539599, DQ631466, DQ631532; USA: Kentucky, Dobertson Co.
(1995), MA 721314.Sphenopus divaricatus (Gouan) Reichenb.—
AF532939, AF533033, DQ631493; Spain: Zaragoza, Vedado de
Pen˜aflor, Catala´n et al. (2004).
Triplachne nitens (Guss.) Link—DQ336816, DQ336836, DQ336861;
Spain: Almerı´a, Playa de Carboneras (1982), MA 292711.Trisetum
baregense Laffitte & Mie´ geville—DQ539605, DQ631471,
DQ631537; Spain: Huesca (1998), JACA 120998.T. drucei Edgar—
AY752485, —, —; Gardner et al. (unpublished). T. dufourei Boiss.—
DQ539606, —, —; Spain: Ca´diz (1993), JACA 284999.T. flavescens
(L.) P. Beauv.—DQ336830, DQ336850, DQ336877; Bulgaria (2004),
CA 10141.T. glaciale Boiss.—DQ539614, DQ631477, DQ631543;
Spain: Granada, Pico Veleta (1986), MA 398253.T. gracile (Moris)
Boiss.—DQ539607, DQ631472, DQ631538; Italy: Sardegna (2003),
SC 17158.T. hispidum Lange—DQ336831, DQ336851, DQ336376;
Spain: Leo´n, Valverde de la Sierra (1994), MA 542627.T.
loeflingianum (L.) P. Beauv.—DQ539608, DQ631473, DQ631539;
Spain: Huesca (1996), JACA 307296.T. ovatum Pers.—DQ336832,
DQ336852, DQ336878; Spain: Toledo, Hinojosa de San Vicente
(1995), MA 556705.T. p an i ceu m (Lam.) Porsild—DQ539609,
DQ631474, DQ631540; Spain: Jae´n, Andu´jar (2003), MA 652453.T.
spicatum (L.) K. Richt.—AY752486,—,—; Gardner et al.
(unpublished). T. tenellum (Petrie) A.W. Hill—AY752487, —, —;
Gardner et al. (unpublished). T. turcicum Chrtek—Z96902 & Z96903,
—, —; Grebenstein et al. (1998); Caucasus, Dzhavachethi. T. youngii
Hook. f.—AY752488, —, —; Gardner et al. (unpublished).
Ventenata dubia (Leers) Cosson—DQ539572, DQ631434, DQ631500;
Bulgaria (2004), CN 5025.Vulpia myuros (L.) C.C. Gmel.—
AY118092, AY118103, DQ631489; USA: Washington, Seattle,
Lake Forest Park, Catala´n et al. (2004).
Wangenheimia lima (L.) Trin.—AF478498, AF478536, —; Spain:
Zaragoza, Vedado de Pen˜aflor, Catala´n et al. (2004).
Zingeria trichopoda (Boiss.) P. A. Smirn.—AJ428835, —, —; Kotseruba
et al. (2003).
September 2007] QUINTANAR ET AL.—PHYLOGENY OF TRIBE AVENEAE 1569