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Sardinia is a major centre of diversity of Anchusa, but the systematics, phylogenetic relationships and conservation status of the taxa endemic to the island are still poorly known mainly because of their remarkable rarity. We present a study on these endemics based on the results of field research focusing on the distribution, the number and size of the populations, the characteristics of the habitat and the factors of threat. Combined with observations on aspects of reproductive biology, on wild populations and cultivated plants, we evaluate the conservation status of the taxa and propose Red List IUCN categories of vulnerability. Original descriptions, nomenclatural types and karyological data are added. The following Anchusa taxa are endemic to Sardinia: A. capellii, A. crispa ssp. crispa, A. crispa ssp. maritima, A. formosa, A. littorea, A. sardoa and A. montelinasana sp. nov. The latter is described, based on the discovery of a morphologically distinct entity on a mountain in southwest Sardinia. Anchusa littorea was found at a single site after c. 25 years from the last record and 7 years of unsuccessful field research; this species is at the brink of extinction due to the extremely reduced size of the only remaining population. Our complete collection of taxa allowed an analysis of phylogenetic relationships based on DNA sequences from the ITS1 ribosomal genome. In spite of the low variation, this marker produced Maximum Parsimony and Neighbour-Joining phylograms suggesting that the group is monophyletic and that the split between the two clades of the mountain and coastal endemics has been a key evolutionary event. We assume the three mountain species to be relict schizoendemics ancestral to the coastal taxa, and the Paleozoic siliceous massifs of central and south Sardinia as the centre of origin of the group.
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Systematics and Biodiversity 6 (2): 161–174 Issued 6 June 2008
doi:10.1017/S1477200008002673 Printed in the United Kingdom
C
The Natural History Museum
G. Bacchetta
1
, A. Coppi
2
,
C. Pontecorvo
1
&F. Selvi
2
1
Centro Conservazione
Biodiversit`a (CCB),
Dipartimento Scienze
Botaniche, University of
Cagliari, Viale Sant’Ignazio da
Laconi, 13 I09123, Cagliari,
Italy
Emails: bacchet@unica.it;
la_zappa@libero.it
2
Dipartimento di Biologia
Vegetale, Sezione Botanica
Sistematica, University of
Firenze, Via La Pira, 4 I 50121,
Firenze, Italy
submitted January 2006
accepted September 2006
Systematics, phylogenetic relationships
and conservation of the taxa of Anchusa
(Boraginaceae) endemic to Sardinia (Italy)
Abstract Sardinia is a major centre of diversity of Anchusa, but the systematics,
phylogenetic relationships and conservation status of the taxa endemic to the island
are still poorly known mainly because of their remarkable rarity. We present a
study on these endemics based on the results of field research focusing on the
distribution, thenumber and size of the populations, the characteristics of the habitat
and the factors of threat. Combined with observations on aspects of reproductive
biology, on wild populations and cultivated plants, we evaluate the conservation
status of the taxa and propose Red List IUCN categories o f vulnerability. Original
descriptions, nomenclatural types and karyological data are added. The following
Anchusa taxa are endemic to Sardinia: A. capellii, A. crispa ssp. crispa, A. crispa
ssp. maritima, A. formosa, A. littorea, A. sardoa and A. montelinasana sp. nov. The
latter is described, based on the discovery of a morphologically distinct entity on
a mountain in southwest Sardinia. Anchusa littorea was found at a single site after
c. 25 years from the last record and 7 years of unsuccessful field research; this species
is at the brink of extinction due to the extremely reduced size of the only remaining
population. Our complete collection of taxa allowed an analysis of phylogenetic
relationships based on DNA sequences from the ITS1 ribosomal genome. In spite of
the low variation, this marker produced Maximum Parsimony and Neighbour-Joining
phylograms suggesting that the group is monophyletic and that the split between
the two clades of the mountain and coastal endemics has been a key evolutionary
event. We assume the three mountain species to be relict schizoendemics ancestral
to the coastal taxa, and the Paleozoic siliceous massifs of central and south Sardinia
as the centre of origin of the group.
Key words Anchusa, Boraginaceae, conservation, endemism, molecular phylogeny,
Sardinia, systematics
Introduction
Anchusa L. is one of the major genera of tribe Boragineae
(Boraginaceae), with approximately 30 species mainly dis-
tributed in the Mediterranean basin and Middle East, and
three disjunct African members in the highlands of Eritrea
and Cape region (Gus¸uleac, 1929). Sardinia is a major centre
of diversity and endemism for this genus, with six allopatric
taxa occurring in either coastal or mountain habitats of the
island. However, despite some previous taxonomic contribu-
tions (Valsecchi, 1976; Selvi, 1998; Selvi & Bigazzi, 1998),
these narrow-ranged endemics are still poorly known in terms
of both phylogenetic relationships and conservation status. A
reason for this is their very restricted range and small popu-
Corresponding author. Email: selvi@unifi.it
lation size, which explains the lack of herbarium material in
many European collections and, consequently, the uncertain
and often discordant taxonomic interpretations in past and re-
cent standard floras (Fiori, 1926; Chater, 1972; Pignatti, 1982;
Greuter et al., 1984). Perhaps the only exception is represented
by the psammophytic species, A. crispa Viv., which is the only
member of the group also occurring on the nearby island of
Corsica. The narrow range, the small size of the populations,
the loss of habitat caused by human activities and the negative
effects of other biotic and abiotic factors are the main causes for
which this species is listed in the French and Italian National
Red Lists (Olivier et al., 1995; Conti et al., 1997; Scoppola &
Spampinato, 2005), in the EU Directive 92/43 CEE ‘Habitat’,
in the Berne Convention and finally in a recent IUCN selec-
tion of the 50 most endangered species of the Mediterranean
(De Montmollin & Strahm, 2005). Accordingly, A. crispa has
161
162 G. Bacchetta et al.
been the object of numerous studies on different ecological
and reproductive aspects related to the problems of its in situ
conservation, though almost exclusively on Corsica (Thi
`
ebaut,
1988; Guyot & Muracciole, 1995; Paradis & Piazza, 1988,
2000; Quilichini & Debussche, 2000; Quilichini et al., 2001,
2004).
It is evident, therefore, that the disparity of knowledge
that we have for this ‘target’ species with respect to the other
Sardinian endemics even in basic terms of number and surface
of the populations is not a favourable condition to plan initiatit-
ives for their long-term, in-situ conservation. To fill this gap we
undertook a field-based research to obtain more information
on the distribution, habitat features and demographic condi-
tion of the populations. Seven years of field work allowed us
to find new localities for some of the rarest taxa, to better
understand the biotic and/or abiotic factors that influence the
demographic dynamics of populations, and to establish cor-
rect IUCN categories. This is the essential information to plan
recovery actions of all endangered species (Cropper, 1993;
Frankel et al., 1995). In addition, we discovered a popula-
tion of Anchusa in a rugged mountain area of the southwest-
ern part of the island, whose morphological distinctiveness
allowed us to describe it as a new species. Such an import-
ant discovery made possible a complete collection of mater-
ial for the phylogenetic analysis of the group using sequences
from the non-coding Internal Transcribed Spacer region (ITS1)
of the nuclear ribosomal DNA. The usefulness of this molecu-
lar marker in the species-level systematics of Boragineae has
been demonstrated in recent studies (Hilger et al., 2004; Selvi
et al., 2004). The results of this work are reported in this paper
in order to contribute to a better knowledge and to the con-
servation of this remarkable component of the Mediterranean
insular endemic flora.
Materials and methods
Fieldwork and plant material
This account is mainly based on fieldwork (1998–2005) fo-
cusing on the distribution, ecology and conservation status of
the taxa in terms of number and area of occupancy of the
populations, approximate number of fertile individuals, hab-
itat characteristics and main factors of threat. When possible,
we captured the insects that visited the flowers and made ob-
servations on the means of seed dispersal. We determined the
number of sites recorded previously for each taxon on the
basis of reliable literature data and herbarium specimens in FI,
CAG, SASSA, TO and G. For the rarest species we prepared
fine scale maps, which will allow the detection of eventual
future changes in the area of occupancy of the populations.
Based on these data, we propose conservation categories for
each taxon following the IUCN criteria (IUCN, 2001). In ad-
dition, collection of seed allowed us to make preliminary tests
on germination capacity and to grow plants in the botanical
garden for the purposes of ex situ conservation. During the
years 2000–2005 we monitored the production of viable seed
in isolated plants under cultivation.
Before treating the above-mentioned aspects, we give for
each taxon: (1) the nomenclatural type; (2) a brief morpholo-
gical description based on field notes and herbarium material;
(3) references to selected iconographies and an original illus-
tration of the new species A. montelinasana. The latter species
and the new population of A. formosa from Mount Arcosu
(see below) were also analysed from a karyological viewpoint,
using root tips of seeds germinated in Petri dishes. These were
pre-treated with 0.002 M 8-hydroxyquinoline or 0.05% col-
chicine, 2.5 h at room temperature and then fixed overnight
in ethanol:glacial acetic acid 3:1. The meristematic tissue was
then thoroughly rinsed in distilled water, hydrolysed in 1N
HCl at 60
C for 6–7 minutes, and stained in lacto-propionic
orcein overnight. Meristems were finally dissected, squashed
on clean glass slides in a drop of 45% acetic acid, and observed
with a Zeiss Axioscop light microscopy under oil immersion
(100×).
DNA isolation and amplification
Genomic DNA of the taxa listed in Table 1 was extracted
following a modified 2× CTAB protocol (Doyle & Doyle,
1990) using silica-gel samples of leaf tissue collected in the
field by the authors. Voucher specimens are deposited in FI,
CAG and BM. The extracted DNA was quantified after agarose
gel electrophoresis (0.6% w/v) in TAE buffer (1 mM EDTA,
40 mM Tris-acetate) containing 1 μg/ml of ethidium bromide
by comparison with a known mass standard. The primers ITS4
and ITS5 (Baldwin, 1992) were used for the amplification of
the Internal Transcribed Spacer ITS1 region of nuclear rDNA
intron. PCR amplifications were performed in a total volume
of 50 μl containing 5 μl of reaction buffer (Dynazyme II;
Finnzyme, Espoo, Finland), 1.5 mM MgCl
2
, 20 pmol of each
primer, 200 μM of each dNTP, 1 U of Taq DNA polymerase
Taxa Geographic origin a nd herbarium vouchers
A. capellii Moris Sardinia, Esterzili, Monte S. Vittoria, G. Bacchetta & F. Selvi, 99.002 (FI)
A. crispa Viv. ssp. crispa Corsica, Solenzara, Cannella, M. Bigazzi & F. Selvi, 99.005 (FI)
A. crispa Viv. ssp. crispa Sardinia, Alghero, Porticciolo, M. Bigazzi & F. Selvi, 97.001 (FI)
““ ssp. maritima (Vals.) Selvi & Bigazzi Sardinia, Badesi, mouth of river Coghinas, M. Bigazzi & F. Selvi, 97.005 (FI)
A. formosa Selvi, Bigazzi & Bacchetta Sardinia, Uta, Mt. Lattias, M. Bigazzi & F. Selvi, 97.006 (FI, CAG)
A. littorea Moris Sardinia, Arbus, I s Arenas, G. Bacchetta & C. Pontecorvo (CAG)
A. montelinasana Sardinia, Gonnosfanadiga, Mt. Linas, C. Pontecorvo & R. Angius (CAG, FI)
A. sardoa (Illario) Selvi & Bigazzi Sardinia, Alghero, Porto Conte, M. Bigazzi & F. Selvi, 97.020 (FI)
Table 1 List of the taxa of Anchusa and accessions used for the molecular analysis.
Systematics, phylogenetic relationships and conservation of the taxa of Anchusa (Boraginaceae) endemic to Sardinia (Italy) 163
(Dynazyme II; Finnzyme) and 10 ng of template DNA. Re-
actions were performed in a Perkin-Elmer 9600 thermocycler
(Perkin Elmer, Norwalk, CT, USA). Then, 5 μl of each amp-
lification mixture was analysed by agarose gel (1.5% w/v)
electrophoresis in TAE buffer. The PCR reactions were puri-
fied from excess salts and primer with the PCR Purification
Kit (Roche, Mannheim, Germany). Automated DNA sequen-
cing was performed on both strands directly from the ITS4 and
ITS5 primers on the purified PCR products using BigDye Ter-
minator v.2 chemistry and an ABI310 sequencer (PE-Applied
Biosystems, Norwalk, CT, USA) according to the manufac-
turer’s recommendations.
Sequence alignment and phylogenetic analysis
The nucleotide sequences obtained were checked for ortho-
logy to the sequences of Anchusella cretica (Mill.) Bigazzi,
Nardi & Selvi (GenBank accession AY045716), Anchusa
stylosa M.Bieb. of Anchusa subgenus Buglossellum Gus¸ul.
(AY383308) and Anchusa azurea Mill. of Anchusa subg. Bu-
glossum Gus¸ul. (AY383293). Based on their position in a
recent phylogeny of tribe Boragineae (Hilger et al., 2004),
we then used these species as outgroup representatives for
dendrogram construction. Multiple alignment was performed
with the program Multalin (Corpet, 1988), and then further
examined and slightly modified manually. All characters were
weighted equally, and character state transitions were treated
as unordered. Gaps were coded and added at the end of the
sequences according to the ‘simple gap’ coding method after
Simmons & Ochoterena (2000). Neighbour-Joining (NJ), and
Maximum Parsimony (MP) methods were used to analyse the
aligned sequences. NJ trees (Saitou & Nei, 1987) were ob-
tained on the basis of a Kimura-2 parameter distance matrix.
MP trees were calculated with PAUP ver. 4.0b (Swofford,
1998) through heuristic search adding sequences at random
with Tree-Bisection-Reconnection branch swapping. Accel-
erated transformation (ACCTRAN) optimisation was used to
infer branch lengths. Internal support to the branches was es-
timated by means of 50% Majority-Rule bootstrap analysis
with 1000 replicates (Felsenstein, 1985).
Results
Anchusa formosa Selvi, Bigazzi & Bacchetta, Pl. Biosys. 131:
104. 1997. — Type: holo-FI; iso- FI, CAG, SASSA.
Perennial. Hispid for stinging, patent setae up to 3.1 mm long
and inserted on prominent tubercles, and sparse, shorter hairs.
Stems up to 40 cm, prostrate-ascending to decumbent. Basal
leaves in a dense rosette, 8–18(30) × 2.5–5(8) cm, bright green,
ovate to oblanceolate, tapering into a short petiole, with entire,
flat margins; cauline leaves smaller, sessile. Cymes branched
distally, scarcely elongated in fruit. Bracts triangular-ovate,
slightly shorter than calyx. Flowers subsessile, with calyx 5–6
mm long, divided to c.
1
/
4
. Fruiting calyx ventricose-urceolate,
costate, with reflexed teeth. Corolla with tube c.5mmand
limb subrotate, c. 8 mm in diameter, light blue-violet. Anthers
1.7 mm, partially overlapping scales. Homostylous; style c.5
mm. Mericarpids obliquely ovoid, small, c.2× 1.5 mm, with
a weak basal rim; surface blackish, minutely papillose, with
Figure 1 Distribution of the endemic Anchusa in Sardinia. Solid
symbols refer to confirmed sites; empty symbols refer to
historical (not confirmed) sites.
a reticulation of blunt ridges. Flowering during April–June,
secondarily to July; fruiting during May–July.
Iconography.S
ELVI et al. (1997: Fig. 1).
Reproductive biology
Allogamous pollination is by means of insects. The follow-
ing taxa were observed to visit the flowers with high fre-
quency: Apis mellifera, Halictus sp. (Hymenoptera), Lasiom-
mata tigelius, Coenoympha corinna (Lepidoptera), Bombylius
sp. (Diptera), Divales cinctus, Oedemera sp. (Coleoptera). In
cultivated plants, however, self-pollination plays an important
role and production of viable seed is abundant. Seed dispersal
is operated by ants and running water along mountain chan-
nels. Seed set is high in either wild or cultivated plants, and
percentage of germination is high (c.90%).
Chorology. SW Sardinian endemic (region of eastern Sulcis)
Since its description the species was known for only the Senna
Manna and Su Fundu channels which run down from the east-
ern side of Monte Lattias. Our field researches led to the dis-
covery of a second, small population at Su Scavoni, a locality
on the north-eastern side of Monte Arcosu c. 4.5 km at the
north from the first one (Figs 1, 2).
164 G. Bacchetta et al.
Figure 2 Area and location of the populations of (top left) A. montelinasana (Mt. Linas); (top right) A. formosa (Mt. Arcosu); (lower left) A.
littorea (Is Arenas); (lower right) A. capellii (Mt. Santa Vittoria). A map of the Monte Lattias population of A. formosa is published in
Selvi et al. (1997).
Habitat and ecology
The species grows on incoherent material of erosion in rocky
channels with an inclination between 5
and 45
. Rock type is
granite of Hercinian origin. The Mt. Lattias population consists
of three subpopulations located at c. 550–580 m, 620–680 and
700–795 m respectively; the Mt. Arcosu site is at 860 m a.s.l.
Both are faced to the east and lie in the mesomediterranean up-
per subhumid-lower humid bioclimatic belt (upper subhumid
to lower humid ombrotype). Associated endemic taxa are Cym-
balaria aequitriloba (Viv.) Cheval., Scrophularia trifoliata L.,
Hypericum hircinum L., Teucrium marum L., Stachys corsica
Pers., Digitalis purpurea L. var. gyspergerae (Rouy) Fiori,
Rumex scutatus L. ssp. glaucescens (Guss.) Brullo, Scelsi &
Spampinato.
Demographic condition, conservation status and IUCN
category
The Monte Lattias and Monte Arcosu populations consist of
c. 1500 and 650 plants, respectively; their total surface of occu-
pancy is c. 2.7 hectares (Table 2). The species is not currently
included in any type of national Red List, but its rarity and
small population size suggest that it should be included in the
VU category (Table 3). However, it is not severely threatened
with extinction mainly because both populations lie in the
heart of a wilderness area which is part of the WWF Nature
Reserve and site of Comunitarian Interest ‘Monte Arcosu’
(code ITB 041105), and of the regional park ‘Sulcis’ (regional
law 31/89). The remarkable demographic fluctuations in the
Mt. Lattias population were caused by natural events. During
autumn and winter 2002–2003, severe rainfall and flooding in
the area caused the destruction of the population in the lower
part of the channels, while the upper part was less damaged.
In 2004, however, the species re-appeared in the lower part,
with numerous seedlings established in sand pockets and other
favourable micro-sites. The Mt. Arcosu population shows nar-
rower fluctuations thanks to the greater stability of the local
rock formation.
Anchusa capellii Moris, Stirp. Sard. El. 2: 6. 1827. Type:
lecto-TO Herb. Moris.
Perennial. Hispid-pubescent for tubercle-based, hyaline setae
up to 2 mm long, mixed to dense, shorter hairs. Stems up to
40 cm, prostrate-ascending to decumbent. Basal leaves form-
ing a rosette, oblanceolate, 7–14 × 1.5–3.5 cm, the cauline
Systematics, phylogenetic relationships and conservation of the taxa of Anchusa (Boraginaceae) endemic to Sardinia (Italy) 165
Taxa n.s. n. p. n. ind. Area Trend Main factors of disturb and threat
A. capellii 2 1 1.000 34.800 stable grazing, natural events
A crispa ssp. crispa 9 3 2.100 60.000 declining habitat loss by human activity, alien species
A. crispa ssp. maritima 5 5 6.000 90.000 declining habitat loss by human activity, alien species
A. formosa 1 2 2.150 20.740 stable natural events
A. littorea 6 1 350 2.800 declining habitat loss by human activities, alien species
A. montelinasana 1 200 43.950 ? grazing, natural events
A. sardoa 1 1 1.500 30.000 declining habitat loss by human activities, tourism
Table 2 Total number of sites recorded previously (n.s.), number of populations currently confirmed (n.p.), estimated number of fertile
individuals (n.ind.), approximated area of occupancy of the populations (m
2
), demographic trend, and main factors of threat of the
Sardinian endemics.
Taxa Habitat 92/43 National IUCN Proposed IUCN category ex situ
A. capellii absent CR VU B2a; D1+2 CCB, FI, JBV
A crispa ssp. crispa present EN CR B1ab(iv)c(iv)+2ab(iv)c(iv) FI, CCB
A. crispa ssp. maritima present EN VU B1ab(iii)+2ab(iii); D2 FI, CCB
A. formosa absent VU B2ac(iv); D2 CCB, FI, JBV
A. littorea absent CR CR B1ab(iv)+2ab(iv) CCB
A. montelinasana absent EN D CCB, FI
A. sardoa absent CR B2ab(iii) CCB, FI
Table 3 Presence/absence in the EU Directive Habitat 92/43, current IUCN category at the national level, category here proposed and
location of ex situ collections of seeds or living plants of the Sardinian Anchusa endemics (CCB: Biodiversity Conservation Centre,
Cagliari, Italy; FI: University Botanical Garden, Firenze, Italy; JBV: Jard´ıBot`anic Val`encia, Spain).
progressively smaller, subsessile. Cymes dense at first, but
elongating and becoming lax in fruit. Bracts as long as or
longer than calyx, ovate-lanceolate. Pedicels elongating in
fruit up to 8 mm, often deflexed. Calyx 6–7 mm divided to
c. 2/3, broadly campanulate in fruit. Corolla tube 5–6 mm;
limb sky-blue, c. 12 mm diameter, subrotate. Anthers 2.2 mm,
partially overlapping scales. Heterostylous; stigma capitate-
bilobed. Mericarpids c.2.8× 1.8 mm, obliquely erect, with
a distinct basal annulus, surface sparsely tuberculate, dark-
brown. Flowering occurs during April–June; fruiting occurs
during June–July.
Iconography. Selvi (1998: Fig. 6); Fig. 4D–E (original).
Reproductive biology
Pollination is, at least in part, by means of insects, either
Hymenoptera (Apis mellifera, Tetralonia malvae), Diptera
(Bombylius sp.) or Lepidoptera (Maniola nurag). Cultivated
plants are able to produce progeny through inbreeding. Seed
set is high in either wild or cultivated plants, and percentage
of germination is always elevated (c. 85%). Seed dispersal is
mainly facilitated by ants. Unlike the report of Selvi (1998),
A. capelli is heterostylous, with short-styled (thrum) and long-
styled (pin) forms in an approximately 3:1 ratio. A dominance
of the thrum form was also found in A. undulata ssp. hybrida
(Dulberger, 1970), but this was not confirmed by Selvi (1998)
on a broader sample of the same taxon. As in other Anchusa
species (Phillip & Schou, 1981; Selvi & Bigazzi, 2003) het-
erostyly of A. capellii is ‘imperfect’ as it is not correlated with
the position of the anthers in the corolla tube, which is at the
same height in the two forms.
Chorology. Sardinian endemic.
This species is known for only the top of Monte Santa Vittoria
in central Sardinia (Nuoro province), where it was discovered
by Moris in 1825 (Figs 1,2). A second historical record by
Martelli dated 1888 from the near locality of Taccu de Sadali
could not be confirmed despite our researches in that area
and in other sites with similar geomorphological features (e.g.
Monte Lusei and Monte Perdedu).
Habitat and ecology
Anchusa capellii grows between 900 and 1200 m s.l.m. in
W-facing rocky channels with a mean inclination of c.35
,
on a metamorphic siliceous substrate (gneiss and fillades) of
Paleozoic (Devonian) origin. The bioclimate is supramediter-
ranean (upper subhumid ombrotype). Plants are established in
rock fissures and earth pockets among stones, together with
several other herbaceous endemics such as Stachys corsica,
(pers.) Cymbalaria aequitriloba (Viv.) A. Cheval., Hypericum
annulatum Moris, Armeria sardoa Spreng., Petrorhagia saxi-
fraga (L.) Link ssp. bicolor (Jord. & Fourr.) Gamisans.
Demographic condition, conservation status and IUCN
category
The single known population consists of c. 1000 individuals
distributed over c. 3.5 hectares (Table 2, Fig. 2). The factors
that determine the sudden disappearance of this species about
100 m below the top of the channels are unknown. The site
is not currently included in any type of protected area and is
subject to grazing by sheep and goats. This is the main factor
of disturbance, which causes the destruction of the aerial parts
of several plants. During the last eight years, however, the
166 G. Bacchetta et al.
Figure 3 Anchusa montelinasana sp. nov. in its natural habitat.
population did not show substantial demographic fluctuations
and is likely to be in a steady state since a long period of time.
A remarkable reproductive efficiency is likely to contribute
to this stability. This suggests that it should be ranked in the
category VU (Table 3) instead of CR as recently proposed
(Scoppola & Spampinato, 2005).
Anchusa montelinasana Angius, Pontecorvo & Selvi, sp. nov.
Type: Italia, Sardegna, Gonnosfanadiga (Cagliari), Monte
Linas sotto punta Sa Cabixettas, 1070 m, 39
26.559 N
8
37.598 E, coll. R. Angius, C. Pontecorvo et G. Mandis 20
Mai 2005 (holo- CAG, iso- FI, BM).
Anchusae capellii similis, a qua tamen differt floribus
minoribus homostylis, calyce ad 1/3 partito, corollae leviter
violacea nec non caeruleis, nuculis minoribus nigrescenti-
bus, annulo basali tenui.
Perennial herb with fusiform taproot. Indumentum of di-
morphic type, with tubercle-based, hyaline setae up to 2 mm
long, and dense, shorter hairs throughout the plant; stems 10–
35 cm, numerous, branched from base, prostrate-ascending.
Basal leaves in a dense rosette, oblanceolate, 5–10 × 1–2 cm,
with slightly undulate margins bearing stiff bristles, tapering
into a short petiole; the cauline sessile and progressively smal-
ler, often almost linear. Cymes initially dense, but elongat-
ing and becoming lax in fruit. Bracts about as long as calyx,
ovate-lanceolate, obscurely cordate at base, hirsute. Flower
pedicels 1–2 mm at anthesis, up to 8 mm in fruit and often de-
flexed. Calyx divided to c. 1/3 into five triangular-ovate, acute
lobes, c. 6 mm long, urceolate-tubulose in flower, up to 9 mm in
fruit; corolla bright blue-violet, with cylindrical tube c.5mm
and subrotate limb c. 8.5 mm in diameter, with rounded lobes,
often pale-violet at the margins. Anthers c. 1.9 mm, inserted at
the top of tube and partially overlapping scales. Homostylous.
Style c. 6 mm long; stigma subtruncate-bilobed, with crowded,
lageniform (flask-like) papillae with a crenulate-digitate plate-
like cap. Mericarpids transversely ovoid, c.2.1× 1.7 mm,
blackish, coat surface finely tuberculate and with a reticula-
tion of blunt ridges, and thin basal annulus. Flowering occurs
during May–June; fruiting occurs during June–July.
Iconography. Figs. 3, 4A–C (original).
Note. Anchusa montelinasana is morphologically close to A.
capellii, but differs from the latter in a combination of quantit-
ative and qualitative characters of taxonomic value (Table 4).
Adult plants are mostly of smaller size, with a more slender
habit and shorter stems. Calyx is smaller (6.5 vs. 7.6 mm) and
most important, less deeply divided (1/3 vs. 2/3 in A. capellii;
Fig. 4B, D); degree of calyx incision is an important taxo-
nomic character in Anchusa (Gus¸uleac, 1929; Chater, 1972;
Selvi & Bigazzi, 1998, 2003). Unlike in A. capellii, sepals
are thickened along the median vein and have more evident
hyaline margins. The corolla is also distinctly smaller, reach-
ing c. 8 mm in diameter vs. 11–12 mm in A. capellii,andis
characterised by a distinct violet component, which is absent
in the latter (flowers are sky-blue). Finally, mericarpids are
smaller and have a blackish coat surface, while the reticulation
of A. capellii is dark grey-brown; the basal ring is distinctly
more thickened in A. capellii. The last important character is
the lack of heterostyly in A. montelinasana, as revealed by the
examination of 100 fertile plants in the field.
Like all the other endemics treated here, A. montelinasana
is diploid with 2n
= 16 (Fig. 5). In karyotype formula this
Systematics, phylogenetic relationships and conservation of the taxa of Anchusa (Boraginaceae) endemic to Sardinia (Italy) 167
Figure 4 A–C: Anchusa montelinasana sp. nov. (A) habit, (B) flower with bract, (C) mericarpid; D–E: A. capellii (D) flower with bract,
(E) mericarpid. Scale bars = 10 mm; B, D = 5 mm; C, E = 1 mm.
species is identical to A. formosa (Selvi et al., 1997), but differs
from A. capellii in the presence of six metacentric and eight
submetacentric chromosomes rather than eight metacentrics
and six submetacentrics (Table 5).
Reproductive biology (still poorly known)
Flowers are frequently visited by Hymenoptera (Apis sp.,
Halictus sp.) and long-tongued Diptera (Bombylius sp.), which
are effective pollen vectors. In preliminary tests seeds have
shown an elevated germination capacity.
Chorology
It is endemic to the top of Monte Linas in southwest Sardinia
(Iglesiente), where it was first discovered by C. P. and R. A. in
May 2005 (Figs 1,2).
168 G. Bacchetta et al.
Character A. capellii A. montelinasana A. formosa
Mean length of setae (mm) 2.1 2.0 3.1
Cymes elongating, lax elongating, lax, short, dense
Flowers in all directions in all directions mostly unidirectional
Bracts calyx ± as long as calyx < calyx
Mean length of the calyx (mm) 7.6 6.5 6
Degree of incision of calyx 2/3 1/3 1/4
Pedicels up to 8 mm, deflexed up to 8 mm, deflexed 2–3 mm, patent
Calyx in fruit campanulate, not costate tubulose-campanulate,
weakly costate
ventricose-urceolate, with
reflexed teeth, strongly costate
Mean diam. of corolla (mm) 12.2 8.5 8
Colour of the corolla sky-blue blu-violet blue-violet
Mean length of the anthers (mm) 2.1 1.9 1.7
Mean size of the nutlets (mm) 2.8 × 1.8 2.1 × 1.7 2 × 1.5
Mean weight of the nutlet (dry) 0.00403 0.00254 0.00221
Heterostyly present absent absent
Table 4 Main differential characters between A. capellii, A. montelinasana and A. formosa.
Figure 5 Metaphase chromosome plate of A. montelinasana,2n=
16. Scale bar = 6 μm.
Habitat and ecology
The species grows on the rocky flanks and among stones
in the upper part of three channels (named Su Campu de Is
Sermentus) that originate on the northeastern side of Monte
Linas at c. 1180 m a.s.l.; it suddenly disappears below 1000 m.
The geological substrate consists of granites and metamorph-
ites of Paleozoic origin. The bioclimate is supramediterranean
(lower humid ombrotype). The local plant community is dom-
inated by herbs and low shrubs, and includes other endemics
such as Echium anchusoides Bacch., Brullo & Selvi, Genista
salzmannii DC., Silene morisiana B
´
eg. & Rav., Thymus cath-
arinae Camarda, Viola corsica Nym. ssp. limbarae Merxm. &
Lippert.
Demographic condition, conservation status and IUCN
category
Anchusa montelinasana exists with a single population which
occupies a surface of c. 4.4 hectares. It is subdivided in three
close subpopulations placed along the upper part of adjacent
channels and includes a total of only c. 200 fertile plants
(Table 2; Fig. 2). In spite of such reduced size, flowering and
fruiting are abundant and this suggests that the population has
probably been in a more or less steady demographic state for a
long time. The site is largely free from human disturbance and
included in the Site of Communitarian Interest Linas-Marganai
(ITB041111) and in a proposed regional park (Regional Law
31/89). We propose for this taxon the EN category (Table 3).
Anchusa sardoa (Illario) Selvi & Bigazzi, Pl. Biosys.
132: 136. 1998. – Type: lecto- TO Herb. Moris.
Taxa Karyotype formula Reference
A. capellii (Mt. Santa Vittoria) 2n = 2x = 16:2M+6m+6sm+2st
SAT
Bigazzi et al. 2000
A crispa ssp. crispa (Isola Rossa) 2n = 2x = 16:2M+6m+6sm+2st
SAT
Bigazzi et al. 2000
A. crispa ssp. maritima (Badesi) 2n = 2x = 16:8m+4sm+2st+2st
SAT
Selvi & Bigazzi 1998
A. formosa (Mt. Arcosu) 2n = 2x = 16:2M+4m+8sm+2st
SAT
original
A. littorea (S’Ena Arrubia) 2n = 2x = 16:6m+8sm+2st
SAT
Valsecchi, 1976
A. montelinasana (Mt. Linas) 2n = 2x = 16:2M+4m+8sm+2st
SAT
original
A. sardoa (Porto Conte) 2n = 2x = 16:6m+6sm+2st+2st
SAT
Selvi & Bigazzi 1998
Table 5 Karyotype formula according to Levan et al. (1964) of the taxa of Anchusa endemic to Sardinia.
Systematics, phylogenetic relationships and conservation of the taxa of Anchusa (Boraginaceae) endemic to Sardinia (Italy) 169
Figure 6 Anchusa littorea in its natural habitat.
Perennial. Hispid for dense, stiff, tubercle-based bristles
and shorter hairs. Stems up to 30 cm, erect-ascending. Basal
leaves in a loose rosette, 10–15 × 1–2 cm, ovate-lanceolate,
obtuse, with erose-dentate or crispate-undulate margins; cau-
line leaves similar but smaller, sessile. Cymes several, dense
at anthesis and scarcely elongating in fruit. Bracts foliaceous
always much longer than calyx. Flowers subsessile. Calyx di-
vided to c. 1/2 into five subacute lobes, 9–11 mm long in fruit,
tubulose. Corolla pale blue with tube 4–5 mm and limb 5–7
mm diameter, subrotate. Anthers 1.7 mm, slightly overlapping
scales. Style 4–5 mm long; stigma broadly ovoid with spaced
papillae. Mericarps obliquely ovoid, c.2.5× 1.5 mm, with
a pointed apex, surface light brown-greyish, densely tuber-
culate, with a sparse reticulation of blunt ridges. Flowering
occurs during May–June; fruiting occurs during June–July.
Iconography. Selvi and Bigazzi (1998: Fig. 17).
Chorology. Sardinian endemic (Nurra region).
This species is known from only the coastal strip of the Porto
Conte bay in NW Sardinia (Fig. 1).
Habitat and ecology
Stable and flattened sand dunes are c. 100 m from the seashore,
mainly under artificial Pinus sp. pl. canopy. The bioclimate
is thermomediterranean (upper dry-lower subhumid ombro-
type).
Reproductive biology
Flowers are abundantly visited by Hymenoptera and long-
tongued Diptera, which are likely to be the main pollen vectors.
Like the other taxa, however, isolated plants in cultivation are
able to produce offspring through inbreeding.
Demographic condition, conservation status and
IUCN category
The only known population of A. sardoa consists of five sub-
populations of c. 250 individuals each, distributed over a total
surface of c. 3 hectares (Table 2). Unlike A. capellii and
A. formosa, this species is in a declining demographic status,
due to the heavy anthropic disturbance of the site where it
grows. Tourism, car parking, pollution, afforestation, tramp-
ling and cleaning of the beach with mechanical means during
the growing season are the main factors that are causing hab-
itat loss and reduction of the population. This justifies the
application of the CR category (Table 3).
Anchusa littorea Moris, Atti Congr. Sci. Ital. Genova, 8: 566.
1846. – Type: lecto- TO Herb. Moris.
Annual. Hispid-setose for dense, tubercle-based trichomes and
shorter hairs. Stems decumbent to suberect, branched from
base, 4–15 cm. Lower leaves 3–6 × 0.4–0.8 cm, narrowly
oblanceolate and tapering into a short petiole, with repand-
dentate margins; cauline leaves almost linear, smaller and
sessile. Cymes with small flowers distanced at the axyl of cau-
line leaves, often also in the lower part of the stems just above
ground-level, on pedicels 2–3 mm long deflexed in fruit. Calyx
tubulose, 3.5 mm, divided to 1/2–2/3 into narrowly triangular
lobes, up to 5 mm and spherical-urceolate in fruit. Corolla with
tube 4 mm long and limb 4–5 mm diam., light blue or white,
rotate with rounded lobes. Anthers 1.3 mm, not overlapping
scales. Style slightly longer than calyx. Mericarps light grey-
brown, small, 1.5–2 × 0.5–1 mm, with a lateral beak and a thin
basal annulus, with finely tuberculate surface. Flowering oc-
curs during March–May; fruiting occurs during March–June.
Iconography. Moris (1837–59, Fig. 49); Valsecchi (1988,
Fig. 1); Fig. 6.
170 G. Bacchetta et al.
Reproductive biology (almost unknown)
Although some insects’ activity has been observed in the single
known population, autonomous self-pollination is likely to
be the main reproductive system. Seed dispersal is mainly
performed by wind and ants.
Chorology
Endemic to southwest Sardinia (Sulcis and Iglesiente), and re-
corded previously for the following localities: S’Ena Arrubia,
Terralba, Marina di Arbus, Piscinas, Is Arenas, Sant’Antioco
at Calasetta bay and San Pietro at Spalmatore (Fig. 1). Only
in one of these localities, however, is the species currently
confirmed (see below).
Habitat and ecology
Anchusa littorea is a psammophytic species growing on large,
mobile dune systems of siliceous sand, in the discontinuities of
Juniperus oxycedrus L. ssp. macrocarpa (Sibth. & Sm.) Neirl.
shrubs. The bioclimate is upper thermomediterranean (lower
subhumid ombrotype). In the only locality where we could
oberve it, associated taxa are therophytes such as Linaria flava
(Poiret) Desf. ssp. sardoa (Sommier) Arrigoni, Phleum sar-
doum (Hackel) Hackel, Malcolmia ramosissima (Desf.) Thell.,
Tuberaria guttata (L.) Fourr., Polycarpopon alsinifolius (Biv.)
DC., Silene nummica Vals. and others.
Demographic condition, conservation status and
IUCN category
The rediscovery of A. littorea at Is Arenas comes after 8 years
of unsuccessful field research at all the sites where it was recor-
ded previously and in other coastal localities of SW Sardinia.
The last previous record was at ‘Spiaggia di Arborea’ near
Oristano and dates back to April, 4, 1981 (L. Mossa, CAG!).
At that site, however, the species has never been observed
since. We failed to find it at most of the other localities (from
north to south: Terralba, Marina di Arbus, Piscinas, San Pietro
and S’Antioco islands), and it has not been observed for over
25 years.
The population found in spring 2005 consisted of only
c. 350 plants distributed over a surface of c. 2800 m
2
(Table 2,
Fig. 2C). The area is legally closed to the public and included in
the Site of Communitarian Interest ‘Piscinas-Rio Scivu’ (ITB
040071). In spite of this, the site is frequented by local people
for recreation purposes and is crossed by a footpath, which is
the continuation of a service road. Anthropogenic disturbance
contributes to the limitation of the habitat available for this
species, which is at the brink of extinction due to the extremely
reduced range and small population size coupled with the lack
of ex situ collections. Its steep decline justifies the category
CR (Table 3) and underscores the need for specific actions of
conservation.
On the other hand, the remarkable rarity and fugacity of
this species may also be associated with its peculiar biological
and ecological features. In fact, this is the only member of the
group that shows a terophytic habit and a strongly abbreviated
life cycle. A typical trait of its ‘ephemeral’ like biology is
the unique capacity to produce flowers and fruits shortly after
seed germination, when plants are still in an apparently juven-
ile state (Fig. 6). The very small mericarpids are produced
in spring contemporarily to flowers, even through selfing,
and then immediately released in the mobile sands of dunes
exposed to seawind. They are easily moved with sand by wind
and can remain latent for several years to germinate only when
edaphic humidity and position in terms of underground depth,
distance from the sea and type of surrounding vegetation are in
an optimal combination. This may account for the strong spa-
tial and temporal discontinuity with which this species appears
along the windy coasts of southwestern Sardinia.
Anchusa crispa Viv., App. Fl. Cors. Prodr. 1: 1. 1825. – Type:
lecto- G-DC.
Perennial to biennial. Hispid-setose for tubercle-based
bristles, up to 2 mm long and dense, shorter hairs. Stems
10–40 cm, prostrate or prostrate-ascending. Basal leaves in
a loose rosette, 80–120 × 3–8 mm, sublinear or narrowly
oblanceolate, obtuse, with undulate-crispate margins; cauline
leaves linear, sessile. Cymes several, dense or lax at anthesis,
slightly elongating in fruit. Bracts triangular-ovate, subequal
to flowering calyx. Pedicels up to 2 mm in fruit. Flower-
ing calyx 5–7 mm, up to 5 mm wide and 6–8 mm long in
fruit, subglobose-urceolate, divided to 1/3–1/2 into five obtuse
lobes. Corolla blue or rarely whitish to violet, with tube 4–5
mm and limb 6–7 mm diam., rotate with subtruncate, rounded
lobes. Anthers c. 1.7 mm, slightly overlapping scales. Style 4–5
mm long; stigma capitate-ovoid. Mericarpids obliquely ovoid,
c.2.1× 1.3 mm, with a blunt apex, surface greyish, tuber-
culated, with a reticulation of blunt ridges. Flowering occurs
during April–July; fruiting occurs during June–July.
subsp. crispa. Basal leaves narrowly oblanceolate, 5–8 mm
wide. Bracts flowering calyx. Calyx divided to 1/2–1/3,
with lanceolate lobes. Corolla limb c. 6 mm in diam. Stigma
usually placed at the same level or below the level of anthers.
Iconography. Valsecchi (1976: Fig. 5; 1988: Fig. 1); Selvi and
Bigazzi (1998: Fig. 15).
Reproductive biology
The following insects were frequently observed to visit
the flowers: Bombus sp. (Hymenoptera, Apidae), two spe-
cies of Osmia sp. (Hymenoptera, Megachilidae), two spe-
cies of Megachile sp. (Hymenoptera, Megachilidae)and
Bombylius sp. (Diptera). However, the occurrence of
autonomous self-pollination has recently been established
(Quilichini et al., 2001). The species shows stylar polymorph-
ism, which is partly correlated with geographic regions. In
ssp. crispa, the stigma is placed at the same level or below
the level of anthers (Quilichini et al., 2004). Seed dispersal is
performed by ants (Quilichini & Debussche, 2000), rarely by
water or cows, at least on Corsica (De Montmollin & Strahm,
2005).
Chorology. Cyrno-Sardinian endemic.
In Sardinia it is restricted to the northern coasts of the island
and recorded for the following localities (Fig. 1): Porticciolo,
Porto Palmas, Stintino (Spiaggia della Pelosa) Tonnara Saline,
Stagno di Pilo, Foce di Fiume Santo, Porto Torres, Isola Rossa
and Torre Vignola. Our field research, however, allowed us to
confirm only three of these localities (see below).
Systematics, phylogenetic relationships and conservation of the taxa of Anchusa (Boraginaceae) endemic to Sardinia (Italy) 171
Number of ITS1 position
Taxa 21 63 77 88 114 160 183 201 274 GenBank
A. capellii A T A T C A T A A AY383297
A. crispa ssp. crispa (Corsica) A G G C C A C G A AY071853
A. crispa ssp. crispa (Sardinia) G G T C A C G C DQ882246
A. crispa ssp. maritima G A C C C C G C DQ882247
A. formosa A G A T C A C A A AY383299
A. littorea G A C C A C G C DQ882248
A. montelinasana G A T C A C A C DQ882250
A. sardoa G G C C A C G C DQ882249
A. undulata ssp. hybrida A G A C A A C G A AY383300
Table 6 Condensed alignment of variable positions (in column) in the ITS1 region of the in group endemics.
Habitat and ecology
Subspecies crispa is found on maritime sands and fairly firm
dunes, and sandy fields near to the sea, often within the associ-
ation of Ammophiletum arundinaceae Br.-Bl. 1921 (Paradis &
Piazza, 1988). The bioclimate is thermomediterranean (upper
dry-lower subhumid ombrotype).
Demographic condition, conservation status and
IUCN category
The taxon is currently confirmed for only three localities: Isola
Rossa, Porticciolo and Torre Vignola. At Isola Rossa the pop-
ulation is established in two small sandy bays separated by a
rocky promontory and consists of c. 1600 individuals, while
at Torre Vignola there are only c. 150 plants. In the small bay
of Porticciolo, the population consists of c. 400 adult plants.
On the contrary, the species has apparently disappeared in the
other localities where it was present previously: Porto Torres,
Foce di Fiume Santo, Stagno di Pilo, Tonnara Saline, Stintino
and Porto Palmas (Moris, 1837–59; Valsecchi, 1976). There
is little doubt that the destruction of the habitat caused by hu-
man activities is the main reason for the extinction of these
populations. A second negative factor is the competition of the
aggressive alien species, Carpobrotus acinaciformis (L.) L.
Bolus, which is increasingly colonising the coastal habitats of
Corsica and Sardinia (Bacchetta, 2001). On the contrary, there
is no evidence for the presence of the exotic ant, Linepitema
humile, in Sardinia, which has been observed to negatively af-
fect the dynamics of seed dispersal of the Corsican populations
(Quilichini & Debussche, 2000). Finally, natural events may
also cause the decline of populations of A. crispa, as in the case
of the severe storms of December 1999 on the western coast of
Corsica (Paradis & Piazza, 2000). The current category for this
taxon in Italy is EN (Conti et al., 1997; Scoppola & Spamp-
inato, 2005), but the strong demographic decline and critical
conservation status caused by the factors mentioned above jus-
tify the category ‘CR’ in accordance with the recent evaluation
in De Montmollin and Strahm (2005).
subsp. maritima (Vals.) Selvi & Bigazzi, Pl. Biosys. 132: 136.
1998. – Type: holo- SASSA, iso-FI
Basal leaves linear, 3–4 mm wide. Bracts slightly shorter
than calyx. Calyx divided to c. 1/3, with rounded lobes. Flowers
c. 7 mm in diam. Stigma usually placed above the level of
anthers.
Iconography. Valsecchi (1976: Fig. 9); Selvi and Bigazzi
(1998: Fig. 15).
Reproductive biology.Likessp.crispa.
Chorology. Sardinian endemic.
Described as Anchusa maritima (Valsecchi, 1976), the
taxon is closely related to ssp. crispa and intermediate forms
occur, especially at Isola Rossa and Torre Vignola. It grows
in the large, sandy bay of the Coghinas River, Gallura. The
following localities are confirmed: La Ciaccia, Valledoria, San
Pietro a Mare, Codaruina, mouth of the Coghinas River, Baia
delle Mimose, Badesi Mare at Li Junchi (Fig. 1).
Habitat and ecology.LikeA. crispa ssp. crispa.
Demographic condition, conservation status and IUCN
category
This taxon occurs almost continuously in the Coghinas bay
from S. Pietro a Mare to Badesi. Here it forms a single large
population consisting of several subpopulations with a patchy
distribution. Like ssp. crispa it is facing increasing loss of hab-
itat and disturbance as a consequence of the anthropogenic use
of the sandy strip and invasion of Carpobrotus acinaciformis.
However, we estimate a total number of individuals of c. 6000,
distributed along a coastal stretch of c. 9 km. The taxon is cur-
rently listed in the ‘EN’ category (Scoppola & Spampinato,
2005), but under IUCN criteria it should be placed in the VU
category (Table 3).
Phylogenetic relationships
ITS1 sequences are deposited in GenBank-EMBL-DDB and
can be retrieved using the accession numbers reported in
Table 2. The aligned sequence data set (available from the
authors in ‘nexus’ format upon request) is 278 bp long. In the
Maximum Parsimony analysis, 217 positions are constant, 51
are parsimony non-informative and 10 are parsimony inform-
ative. Thus, only a small proportion (3.6%) of the ITS1 region
has a useful phylogenetic signal in this group of Anchusa.
Variable positions within the ingroup, cut and condensed, are
showninTable6.
172 G. Bacchetta et al.
Figure 7 Neighbour Joining tree from ITS1 sequences. L = 75, CI = 0.91 and RI = 0.67. Bootstrap support values are reported above branches
when > 50%.
The heuristic search produced 75 most parsimonious
trees with Length = 75, Consistency Index (CI) = 0.91 and
Retention Index (0.67). The Neighbour Joining tree is topo-
logically identical to some of the most parsimonious phylo-
genies and is shown in Fig. 7; bootstrap values > 50% are
shown above the branches. The monophyly of Anchusa subg.
Anchusa includes the mainly continental A. undulata ssp. hy-
brida, which receives a medium support (75% BS), as well as
the clade of the insular species endemic to Sardinia, the object
of this study (76% BS). The latter is split in two sister lineages,
the rst of which consists of the three mountain species, A. for-
mosa, A. capellii and the newly described A. montelinasana
(68% BS). Their ITS1 sequences differ in four positions. Pos.
21 is shared by A. formosa and A. capellii, while A. montelinas-
ana is characterised by one bp deletion; pos. 63 and 183 are
shared by A. formosa and A. montelinasana, while it differs
in A. capellii; pos. 274 is shared by A. formosa and A. capel-
lii and differs in A. montelinasana. In the phylogenetic tree,
this species is basal to the two others, which appear to be sis-
ters. The second lineage (BS < 50%) is formed by the littoral
entities A. sardoa, A. crispa ssp. crispa, A. crispa ssp. mari-
tima and A. littorea
, and is divided in two subgroups, which
are not very consistent with either taxonomy or geographic
distribution. One includes A. littorea and the Sardinian acces-
sion of A. crispa ssp. maritima from the Coghinas bay, while
the second is formed by the eastern Corsican accession of
A. crispa ssp. crispa, which is sister to a terminal clade with
the Sardinian accession of the same entity and A. sardoa.
Discussion
Systematics and phylogenetic hypotheses
The discovery of the new species A. montelinasana brings to
seven the number of taxa endemic to Sardinia, providing fur-
ther evidence for the role of this island as a centre of diversity
of Anchusa in the Mediterranean. Preliminary considerations
on the hypothesis of a common origin for this insular en-
demic group were proposed on a morphological basis, although
no cladistic analyses were performed to test its monophyly
(Selvi & Bigazzi, 1998). More recently, a phylogenetic study
of tribe Boragineae based on plastid and nuclear DNA markers
showed the weak divergence of the clade A. capellii / A. for-
mosa, but the incomplete taxonomic sample of that analysis
was a major obstacle to visualise relationships in the whole
group (Hilger et al., 2004). The present reconstruction, which
is the first one based on DNA sequences from the entire set of
taxa known to date, suggests that the Sardinian endemics form
a monophyletic clade possibly sister to the euri-mediterranean
complex of A. undulata. Due to the low levels of variation of
ITS1 sequences recently observed in the whole group of An-
chusa sensu stricto (Hilger et al., 2004), the slight divergence
shown by the Corso-Sardinian clade acquires a relevant phylo-
genetic meaning and finds support in the morphological syn-
apomorphies that discriminate the insular endemics from the
rest of the genus. These are mainly represented by the special
type of dimorphic indumentum, the prostrate-ascending habit,
the brachymorphic flowers with relatively short tube and sub-
rotate, rather than hypocrateriform, limb, the small anthers,
and the tiny nutlets with a thin basal ring (Gus¸uleac, 1929;
Valsecchi, 1976; Selvi & Bigazzi, 1998). A further ecological
synapomorphy of the group, which is not found elsewhere in
the genus, is the edaphic preference for incoherent, siliceous
substrates, a factor which contributes to explain the absence
in the calcareous massifs of central-eastern Sardinia. From the
karyological viewpoint, the finding of 2n = 16 in A. mon-
telinasana supports that divergence and speciation in Sardinia
has proceeded at the diploid level, as in most of the continental
species of Anchusa (Smith, 1932; Britton, 1951; Luque, 1983;
Selvi & Bigazzi, 2003). Coupled with the low levels of ITS1
divergence, lack of chromosome variation seems to indicate
that no abrupt genetic changes have occurred during processes
of morphological differentiation. On the basis of available
evidence, we assume therefore that the present-day endemics
Systematics, phylogenetic relationships and conservation of the taxa of Anchusa (Boraginaceae) endemic to Sardinia (Italy) 173
originated in situ from a common ancestor through schizogen-
etic speciation triggered by palaeogeographical events which
have caused the fragmentation and reduction of a formerly con-
tinuous range with consequent isolation of the populations.
Molecular data suggest that a main event in the evolution-
ary history of this group has been the split between the oro-
phytic lineage of A. montelinasana, A. capellii and A. formosa,
and the coastal, psammophytic lineage of A. crispa, A. littorea
and A. sardoa. The question arose whether the former is basal
to the latter or vice-versa. Dune systems of western Sardinia
started to form with the split-off of the Cyrno-Sardinian mi-
croplate from southern France and northeast Spain in the late
Oligocene (c. 30 mya; Westphal et al., 1976; Cherchi &
Montadert, 1982; Speranza et al., 2002), suggesting that
coastal species derived from orophytic progenitors occurring
on pre-existing massifs. Events of colonisation of the sandy
coastline may have triggered a process of speciation and ad-
aptive radiation, which led to the origin of the psammophytic
taxa. In view of the lack of endemics in the rugged mountains
of Corsica, despite their mainly granitic nature, and the much
lower diversification of the group on this island, our hypo-
thesis implies that the Palaeozoic siliceous massifs of south
Sardinia, which were part of the Protoligurian mountain chain
connecting the western Alps to the eastern Pyrenees until the
late Oligocene (Westphal et al., 1976; Cherchi & Montadert,
1982) represent the centre of origin of the insular Anchusa
clade.
Conservation
Field data show that all Sardinian Anchusa taxa survive with
small, isolated populations, consisting of a minimum of 200–
350 (A. montelinasana, A. littorea) to a maximum of 6000
(A. crispa ssp. maritima) individuals. Perhaps with the excep-
tion of only the latter species, all fit into the portrait of the
typical rare and endangered species with fewer than five pop-
ulations and 5000 individuals (Holsinger & Gottlieb, 1991).
As shown for A. crispa (Quilichini et al., 2004) and for other
plant taxa (see reviews in Barrett & Kohn, 1991; Huenneke,
1991), such a small size is likely to determine low levels of ge-
netic variation, further increasing their vulnerability in case of
stochastic events which may cause abrupt habitat changes. On
the other hand, the capacity to produce offspring shown by ex
situ cultivated plants of A. capellii, A. formosa, A. crispa (both
subspecies) and A. sardoa suggests that a balanced mixture
of outbreeding and inbreeding is highly effective in ensuring
the reproductive success of natural populations. The intense
activity of insects on flowers of these species and the pres-
ence of nectar ducts and nectar and at the base of the ovaries
(Selvi & Bigazzi, 1998) imply that outcrossing is, at least po-
tentially, one of the two possible reproductive systems. On
the other hand, the capacity of autonomous selfing has been
experimentally demonstrated in A. crispa, in which the close
proximity of stigma and anthers within corollas closed at the
throat by hairy scales favours the direct transfer of pollen
(Quilichini et al., 2001). If on one side selfing is well known
to result in a loss of genetic variation and increase in homo-
zygosity in the progeny (inbreeding depression), on the other
it allows the maintenance and transmission of the genes in-
volved in the effective adaptation of the populations to the
local environment (‘outbreeding depression’, Barrett & Kohn,
1991; Frankel et al., 1995). Combined with high reproduct-
ive efficiency, this may explain the persistence and substantial
demographic stability that we could observe in the mountain
endemics which have not experienced a severe deterioration
or loss of habitat for presumably a very long time. On the con-
trary, the psammophytic taxa which are facing an increasing
anthropic pressure on the coastal ecosystems are in a more
precarious conservation status, despite their wider distribution
in past times. The disappearance of several populations of A.
crispa and A. littorea in sites, which have been strongly altered
by human activities, shows that habitat maintenance is crucial
for the conservation of the populations still surviving along
the north and western coasts of the island. Concrete actions
such as fencing and limitation of invasive plants have been
undertaken for A. crispa on western Corsica (Guyot & Mur-
acciole, 1995; Paradis & Piazza, 2000) and these are urgent
for also Sardinia especially in the case of the only known pop-
ulation of A. littorea. Coupled with the ex situ
conservation
of the germplasm of all existing populations, these actions
should increase the chances of long-term conservation of this
remarkable component of the Mediterranean island endemic
flora.
Acknowledgements
This paper is dedicated to the memory of Professor Massimo Bigazzi,
who prematurely died in April 2006. The authors wish to thank
Hartmut H. Hilger (Berlin) for fieldwork and discussions and
Elisabetta Pirodda and Roberto Angius (Cagliari) for identification
of insects and help with fieldwork. Research grants from M.I.U.R.
and the Universities of Cagliari and Firenze are acknowledged.
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This is the twenty-three of a series of reports of chromosomes numbers from Mediterranean area, peri-Alpine communities and the Atlantic Islands, in English or French language. It comprises contributions on 56 taxa: Anthriscus, Bupleurum, Dichoropetalum, Eryngium, Ferula, Ferulago, Lagoecia, Oenanthe, Prangos, Scaligeria, Seseli and Torilis from Turkey by Ju. V. Shner, T. V. Alexeeva, M. G. Pimenov & E. V. Kljuykov (Nos 1768-1783); Astrantia, Bupleurum, Daucus, Dichoropetalum, Eryngium, Heracleum, Laserpitium, Melanoselinum, Oreoselinum, Pimpinella, Pteroselinum and Ridolfia from Former Jugoslavia (Slovenia), Morocco and Portugal by J. Shner & M. Pimenov (1784-1798); Arum, Biarum and Eminium from Turkey by E. Akalin, S. Demirci & E. Kaya (1799-1804); Colchicum from Turkey by G. E. Genç, N. Özhatay & E. Kaya (1805-1808); Crocus and Galanthus from Turkey by S. Yüzbaşioǧlu, S. Demirci & E. Kaya (1809-1812); Pilosella from Italy by E. Di Gristina, G. Domina & A. Geraci (1813-1814); Narcissus from Sicily by A. Troia, A. M. Orlando & R. M. Baldini (1815-1816); Allium, Cerastium, Cochicum, Fritillaria, Narcissus and Thymus from Greece, Kepfallinia by S. Samaropoulou, P. Bareka & G. Kamari (1817-1823).
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Based on measurements of floral parts and experiments, Anchusa officinalis L. is shown to have a distylous breeding system. Dimorphism is found in the style length/anther height ratio, in stigma morphology and in pollen and corolla size. Plants are self-incompatible but intra- and intermorph compatible. Long-styled plants outnumbered short-styled in all populations. Stigmas in short-styled flowers receive a larger quantity of pollen than those of long-styled.
Article
Sono state esaminate le entità del genere Anchusa presenti in Sardegna. Risultano per l'isola: A. littorea Moris endemica sarda, psammofila e affine ad A. hybrida Ten.; A crispa Viv. endemica sardo-corsa psammofila e vicina ad A. undulata L. e A. calcarea Boiss.; A. undulata L. ssp. undulata v. undulata; A. undulata L. ssp. undulata v. maritima Vals. var. nov., psammofila e nuova per la Sardegna; A. undulata L. ssp. capellii (Moris) Vals. nov. comb., endemica sarda, localizzata a 1200 m, in due località vicine della Sardegna centrale; A. hy brida Ten. nuovo reperto per la flora sarda; A. azurea Mill.È stato accertato il numero cromosomico che per tutte le entità è risultato 2n—16, ad eccezione di A. azurea (2n = 32). Vengono inoltre riferite notizie sulla loro distribuzione in Sardegna e sull'ambiente. The author takes into consideration the species of the genus Anchusa which are present in Sardinia. The following species are listed: A littorea Moris, endemic Sardinian, psammophilous, similar to A. hydrida Ten.; A. crispa Viv., endemic Sardinian-Corsican, psammophilous, closely related to A. undulata L. and A. calcarea Bois.; A. undulata ssp. undulata v. undulata; A. undulata L. ssp. undulata v. maritima Vals, var. nov., psammophilous, new to Northern Sardinia; A. undulata L. ssp. capellii (Moris) Vals. nov. comb., endemic Sardinian, founded in two localities near Esterzili in central Sardinia (1200 m); A. hybrida Ten., new to the Sardinian flora, A. azurea Mill. The chromosome number of all species has been also studied (2n = 16, with the exception of A. azurea 2n = 32). Notes are also given concerning distribution and ecology.
Article
A biometric study of floral morphology in the taxonomically critical Anchusa undulata group from the central-eastern Mediterranean highlights a broad range of individual variation. Anther position is the only character separating A. undulata from A. hybrida, but statistical methods suggest clinal variation connecting the two taxa. A. undulata is also present in continental Greece and intermediate plants occur in Italy, Greece and Israel. This indicates that the two taxa are conspecific and suggests subspecific rank for A, hybrida. Subsp. undulata does not belong to the Italian flora, as samples from Sardinia formerly referred to this taxon belong to a group of psammophytic taxa endemic to northern Sardinia and Corsica. In subsp. hybrida, the distribution frequency of the ratio of style length to anther height shows the occurrence of Short- and long-styled forms, but in neither case is there reciprocal correspondence in the level of anthers and stigmas. In contrast, A. capellii is characterized by some peculiar features with a narrow range of variation, that warrant specific rank for this little-known Sardinian endemic. Specimens from Cyrenaica differ in quantitative and qualitative characters, but a decision on their taxonomic status requires further investigation. Keys and descriptions are provided and lectotypes of A. hybrida and A. capellii are designated.