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Novae Gesneriaceae Neotropicarum XVI: Pearcea pileifolia, a New Species of Gesneriaceae from South America

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A new species of Gesneriaceae (tribe Gloxinieae) is described from Ecuador and Peru in South America. Pearcea pileifolia J. L. Clark & L. E. Skog is vegetatively distinctive from all other species of Pearcea Regel by its oblong leaf blades with crenate to serrate margins and markedly anisophyllous, opposite leaves with the smaller leaf in a pair reduced to a scalelike appendage. Observations of the bivalved fruit dehiscence and the resulting appearance of winged appendages in P. pileifolia and other congeners are discussed.
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Novae Gesneriaceae Neotropicarum XVI: Pearcea pileifolia,
a New Species of Gesneriaceae from South America
John Littner Clark
1,2
and Laurence E. Skog
2
1
Department of Biological Sciences, Box 870345, The University of Alabama, Tuscaloosa,
Alabama 35487-0345, U.S.A. jlc@ua.edu
2
Botany Department, MRC-166, Smithsonian Institution, P.O. Box 37012, National Museum of
Natural History, Washington, D.C. 20013-7012, U.S.A. skogl@si.edu
ABSTRACT . A new species of Gesneriaceae (tribe
Gloxinieae) is described from Ecuador and Peru in
South America. Pearcea pileifolia J. L. Clark & L. E.
Skog is vegetatively distinctive from all other species
of Pearcea Regel by its oblong leaf blades with
crenate to serrate margins and markedly anisophyl-
lous, opposite leaves with the smaller leaf in a pair
reduced to a scalelike appendage. Observations of the
bivalved fruit dehiscence and the resulting appear-
ance of winged appendages in P. pileifolia and other
congeners are discussed.
Key words: Ecuador, Gloxinieae, IUCN Red List,
Pearcea, Peru.
The most recent treatment of the genus Pearcea
Regel (Gesneriaceae) is that by Kvist and Skog
(1996), who recognized 17 species, including nine
new species. The description of P. pileifolia J. L.
Clark & L. E. Skog makes Pearcea a genus of 18
species. It is remarkable that the presently described
species occurs where extensive fieldwork has been
conducted and where several other species were
recently described from Ecuador by Kvist and Skog
(1996). Ecuador is the most diverse country for
Pearcea with 13 species, followed by Peru with seven
species. Pearcea pileifolia has been collected only
four times: three times in Napo Province of Ecuador
and once in the Cajamarca region of Peru. Napo
Province of Ecuador is the most diverse region for
Pearcea with more than half of the species (10 species
of 18) evident in the genus.
The monophyly of the genus Pearcea is well
supported by two separate molecular-based phyloge-
netic analyses that focused on relationships within the
Gloxinieae. Roalson et al. (2005) included four
species of Pearcea as strongly supported based on
nuclear ITS data (nuclear ribosomal DNA ITS region)
and chloroplast data (trnL intron and trnL-trnF
intergenic spacer region). Smith et al. (2004) included
two species of Pearcea as strongly supported based on
nuclear markers (GCYC, which is a Gesneriaceae
homolog of CYCLOIDEA, ITS, and two paralogues of
the nuclear-encoded chloroplast-expressed glutamine
synthetase) and chloroplast markers (ndhF, trnL
intron, trnL-trnF intergenic spacer region, and
rpl20-rps12 intergenic spacer region).
Pearcea differs from related genera in the tribe
Gloxinieae by the detachment of the fruit walls at the
base of a dry bivalved capsule. The detachment of the
fruit wall appears like a pair of winged appendages
(Figs. 1G, H, 2). The fruits of all Pearcea initially
dehisce loculicidally and then secondarily along the
base of the capsule. The walls of the dry capsule
remain attached to the apex of the septum. Thus, the
capsule is nearly circumscissile except for the
persistence of the two septa. This type of secondary
dehiscence is unknown in any other genus of the
Gesneriaceae.
This distinctive fruit dehiscence of Pearcea is
illustrated in P. pileifolia (Fig. 1G, H). Detached fruit
walls were also recently observed and photographed in
many individuals and species of Pearcea (cf.,
selection of some of these images in Fig. 2). Images
of the fruits exist at the Clark Lab (<http://www.bama.
ua.edu/,gesner>) and in the Gesneriaceae photo
library at the Smithsonian Institution’s National
Museum of Natural History and herbarium collections
(MO, SEL, US, UNA, and elsewhere) for the following
species: Pearcea abunda (Wiehler) L. P. Kvist & L. E.
Skog (Fig. 2A), P. hypocyrtiflora (Hooker f.) Regel
(Fig. 2B), P. purpurea (Poeppig) L. P. Kvist & L. E.
Skog (Fig. 2C), P. schimpfii Mansfeld (Fig. 2D), P.
sprucei (Britton) L. P. Kvist & L. E. Skog var. sprucei
(Fig. 2E), and P. sprucei var. parviflora (Rusby) L. P.
Kvist & L. E. Skog (Fig. 2F).
Other fruits in the Gloxinieae are capsules with two
or four valves, but never with detached capsule walls
at the base. The typical fruit in the Gloxinieae is a
bivalved capsule, and some fruits in Kohleria Regel
dehisce by a single longitudinal slit on the dorsal
surface (Kvist & Skog, 1992; Clark & Skog, 2008).
Very few observations of the fruits in Pearcea have
been documented, and only one fruit was illustrated
by Kvist and Skog (1996). The few observations of the
doi: 10.3417/2008004 NOVON 19: 439–443. PUBLISHED ON 10 DECEMBER 2009.
Figure 1. Pearcea pileifolia J. L. Clark & L. E. Skog. —A. Habit. —B. Indument of abaxial leaf surface. —C. Corolla. —D.
Corolla opened to show stamens. —E. Calyx. —F. Calyx opened and corolla removed to show separate nectary glands. —G.
Lateral view of mature fruit with calyx lobes removed. —H. Dorsal view of mature fruit showing valve walls attached to
septum. —I. Seeds. A–I from the holotype, J. L. Clark, E. Narvaez & V. Grefa 5672 (US).
440 Novon
Figure 2. Variation in fruit walls found throughout Pearcea. —A. P. abunda (Wiehler) L. P. Kvist & L. E. Skog. —B. P.
hypocyrtiflora (Hooker f.) Regel. —C. P. purpurea (Poeppig) L. P. Kvist & L. E. Skog. —D. P. schimpfii Mansfeld. —E. P.
sprucei var. sprucei (Britton) L. P. Kvist & L. E. Skog. —F. P. sprucei var. parviflora (Rusby) L. P. Kvist & L. E. Skog. A from J.
L. Clark & D. Menuz, S. Quinn & M. Katan 9132; B from J. L. Clark & D. Menuz, S. Quinn & J. Vargas 9163; C from J. L.
Clark, H. Beltran & I. Salinas 8184; D from J. L. Clark & J. Rea 8037; E from J. L. Clark 7062; F from J. L. Clark 6593.
Volume 19, Number 4 Clark & Skog 441
2009 Pearcea pileifolia (Gesneriaceae) from
South America
fruit in Kvist and Skog (1996: 7) were summarized as
‘‘… field studies showed that Pearcea fruits instead
split from the apex all the way to the base, with two
fleshy valves reflexing to expose a glutinous seed
mass.’’ We suggest that the fruits of Pearcea are not
persistently fleshy as in many of the capsules of
Episcieae, but become dry. Seeds in the capsules of
Pearcea are exposed on reflexed valves that may at
first be fleshy, but the valves persist much longer
(e.g., up to weeks) instead of hours or days as in the
fleshy fruits of Episcieae (e.g., Glossoloma Hanstein or
Drymonia Martius).
A distinctive feature of Pearcea pileifolia is the
change in posture from immature to mature flowers.
Immature flowers of P. pileifolia are appressed to the
abaxial leaf surface until they mature. Upon anthesis
or soon thereafter, the pedicels become erect and the
flowers and subsequent fruits are held above the
leaves on erect pedicels. This has also been observed
in two species of Gasteranthus Bentham (G. leopardus
M. Freiberg and G. wendlandianus (Hanstein) Wieh-
ler); the significance of the change in flower posture
has not been explored, but it may facilitate pollination
or seed dispersal.
Pearcea pileifolia J. L. Clark & L. E. Skog, sp. nov.
TYPE: Ecuador. Napo: Canto
´
n Cando, N of
´
o
Jatunyacu, 01u049450S, 77u569290W, 540 m, 21
Dec. 2000 (fl., fr.), J. L. Clark, E. Narvaez & V.
Grefa 5672 (holotype, US; isotypes, AAU, BM,
BRIT, CAL, COL, E, F, K, MO, NY, P, QCA,
QCNE, SEL, UNA). Figure 1.
Haec species a congeneris laminis foliorum oblongis
margine crenatis vel serratis et foliis valde anisophyllis paris
folio minore in appendicem squamiformem reducto differt.
A terrestrial subshrub; roots fibrous, stolons and
scaly rhizomes absent; stems slender, basal diam. to
3 mm, erect, 40–100 cm tall, terminally branched,
subwoody at base and herbaceous at apex, terete,
sparsely pilose below, densely pilose to villous above.
Leaves opposite, unequal in a pair; larger leaf with
petioles terete, 1–3 mm, green, blade membranous
when dry, oblong, (2–)5–8
3 1–2 cm, base acute and
occasionally asymmetrical, apex attenuate, margin
crenate to serrate, adaxially pale green, sparsely
pilose, abaxially uniformly green, uniformly red, or
green with reddish tinge, uniformly pilose to densely
pilose on veins and leaf margins; smaller leaf sessile
or petiolate, petioles terete, up to 1 mm long, blade
orbicular, 0.5–2
3 1–2 mm, vestiture and coloration
same as larger leaf. Inflorescence epedunculate with
solitary flowers in upper leaf axils; bracteoles absent;
pedicels held below leaves when immature and
becoming erect at anthesis, 2.5–3.5 cm long, densely
pilose. Floral tube conic, 1.5–2.5
3 2–3 mm, densely
pilose; calyx lobes 5, equal, erect at anthesis,
persistent and reflexed in fruit, oblong-lanceolate,
3–5
3 0.5–1.5 mm wide at base, apex attenuate,
margin entire, light green, outside and inside
uniformly pilose; corolla 8–15 mm long, ca. 5.5 mm
diam. medially, uniformly tubular with constriction at
base, horizontal in calyx, outside mostly red with
white base, sparsely pilose, inside mostly white with
red spotting, glabrous, limb with lobes subequal,
reflexed, rotund, ca. 1
3 3 mm wide at base, red,
margin entire; stamens 4, didynamous, included;
filaments 5–6 mm, adnate to base of corolla for 1–
2 mm, glabrous; anthers longer than broad, ca. 2
3
1.5 mm, dehiscing by longitudinal slits; staminode not
observed; nectary of 5 separate glands evenly
distributed around ovary, glabrous, all ca. 0.25
3
0.25 mm; ovary half inferior, ca. 0.5 3 1 mm,
glabrous; style and stigma not observed. Fruit a
globose capsule, ca. 5
3 5 mm, appearing fleshy at
first and then becoming dry, valves reflexed, loculi-
cidally dehiscent, secondarily dehiscent along base
with valve walls attached to septum and appearing
winged; seeds numerous, subglobose, irregularly
striate, ca. 0.3
3 0.3 mm, dark brown.
Distribution and habitat. Pearcea pileifolia is
known from Ecuador on the eastern Andean slopes
in Napo Province and the Cajamarca region of Peru
from 540–2020 m. The forests where P. pileifolia
occurs have been noted on the herbarium labels as
being pluvial premontane, montane wet, or tropical
wet. The species is not locally common, but has been
observed to be abundant along streams (J. L. Clark et
al. 5672) and a ridge (J. L. Clark et al. 5308).
Otherwise, extensive fieldwork throughout Napo
Province between 1997 and 2000 has not resulted in
documenting other populations of this rare species.
IUCN Red List category. Pearcea pileifolia should
be considered Critically Endangered (CR B2b[iv])
according to IUCN Red List criteria (IUCN, 2001).
Farming and human pressures on native flora are
extensive along the eastern border of the Reserva
Ecolo
´
gica Antisana, where one of the two Ecuadorian
populations is known to exist. The population in
Parque Nacional Sumaco Napo-Galeras is 40–45 km
east of the Reserva Ecolo
´
gica Antisana and 15–20 km
east of major cities (e.g., Tena). It is likely that more
fieldwork in these areas will locate additional
populations of P. pileifolia, but so far it is considered
to have a very restricted range. Although the
population observed by the first author was locally
abundant, it is not common along most regions of the
river. It is assumed that populations are limited and
that the range is severely fragmented.
442 Novon
Phenology. Pearcea pileifolia has been collected
in flower in April, November, and December, and
collected in fruit in December only.
Etymology. The epithet pileifolia is derived from
the appearance of the leaves, which are reminiscent of
the widespread genus Pilea Lindley in the Urticaceae.
Pilea is distributed throughout the tropics and
temperate regions and is one of the larger genera in
the Urticales and eudicot rosids. The leaves of
Pearcea pileifolia have crenate margins and brochido-
dromous venation, which are features that resemble
those found in Pilea.
Paratypes. ECUADOR. Napo: Canto
´
n Archidona, Re-
serva Ecolo
´
gica Antisana, comunidad Shamato, entrada por
Km 21–Shamato, camino Sardinas–Shamato, 00u449S,
77u489W, 1700 m, 28 Apr. 1998 (fl.), J. L. Clark, E. Narvaez
& P. Mamallacta 5308 (MO, QCNE, UNA, US); Canto
´
n
Archidona, Parque Nacional Sumaco Napo-Galera, Cordille-
ra de Galeras, Bloque 19,
´
nea 30 (Compan
˜
ı
´
a Triton),
00u539S, 77u339W, 1400 m, 24 Apr. 1996 (fl.), E. Freire & J.
Cerda 543 (MO, QCNE, US). PERU. Cajamarca: San
Ignacio, San Jose
´
de Lourdes, 00u599220S, 78u53930W,
2020 m, 23 Nov. 1999 (fl.), R. Va
´
squez & S. Flores 26324
(US).
Acknowledgments. The authors thank Alain Chau-
tems and Christian Feuillet for helpful comments on
the manuscript. Support for this project for the first
author was provided by the Elvin McDonald Research
Endowment Fund of The Gesneriad Society, the
National Science Foundation (DEB 0841958), and
the Explorers Club Washington Group. We are
grateful to Cathy Pasquale for preparing the illustra-
tion. We thank Harold Robinson and Roy Gereau for
assisting with the Latin diagnosis and the herbarium
QCNE for the specimens on loan.
Literature Cited
Clark, J. L. & L. E. Skog. 2008. Novae Gesneriaceae
Neotropicarum XV: Kohleria hypertrichosa, a new species
of Gesneriaceae from northwestern Ecuador. J. Bot. Res.
Inst. Texas 2(1): 19–24.
IUCN. 2001. IUCN Red List Categories and Criteria, Version
3.1. Prepared by the IUCN Species Survival Commission.
IUCN, Gland, Switzerland, and Cambridge, United
Kingdom.
Kvist, L. P. & L. E. Skog. 1992. Revision of Kohleria
(Gesneriaceae). Smithsonian Contr. Bot. 79: 1–83.
——— & ———. 1996. Revision of Pearcea (Gesneria-
ceae). Smithsonian Contr. Bot. 84: 1–47.
Roalson, E. H., J. K. Boggan, L. E. Skog & E. A. Zimmer.
2005. Untangling Gloxinieae (Gesneriaceae). I. Phyloge-
netic patterns and generic boundaries inferred from
nuclear, chloroplast, and morphological cladistic datasets.
Taxon 54: 389–410.
Smith, J. F., S. B. Draper, L. C. Hileman & D. A. Baum.
2004. A phylogenetic analysis within tribes Gloxinieae
and Gesnerieae (Gesnerioideae: Gesneriaceae). Syst. Bot.
29: 947–958.
Volume 19, Number 4 Clark & Skog 443
2009 Pearcea pileifolia (Gesneriaceae) from
South America
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A new species of Pearcea (Gesneriaceae, Gloxiniinae) is described from the eastern Andes of southern Ecuador where it is endemic to the province of Morona-Santiago. Pearcea lutea differs from other Pearcea by the presence of tubular yellow corollas and a dark red tomentose vestiture on immature stems and leaf undersurfaces. A preliminary designation of Endangered (EN) is provided based on a conservation assessment of IUCN categories.
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Tribe Gloxinieae has been estimated to include 22 genera and approximately 290 species. This study presents maximum parsimony phylogenetic analyses of nuclear ribosomal DNA internal transcribed spacer regions sequences, the chloroplast DNA trnL intron and trnL-trnF intergenic spacer region sequences, a morphological cladistic dataset, and combined analyses of these datasets. These analyses suggest that the genera Gloxinia, Phinaea, and (possibly) Diastema are polyphyletic; Kohleria is paraphyletic in relation to Capanea; Bellonia and Pheidonocarpa should be considered members of tribe Gesnerieae; and Lembocarpus is a member of tribe Episcieae. Furthermore, the historically recognized genus Seemannia, now included in Gloxinia, appears to form a strongly supported monophyletic group; several Gloxinia species from southern Brazil appear to be most closely related to Goyazia; Capanea, Kohleria, Pearcea s. l., and Diastema vexans appear to form a strongly supported clade; and Diastema, Monopyle, Phinaea (in part), and a few Gloxinia species (Gloxinia dodsonii, G. lindeniana, and G. racemosa) form a clade. Classification issues and generic boundaries of these lineages are discussed in detail.
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a new species of Kohleria (Gesneriaceae, tribe Gloxinieae) is described from the andean cloud forests of the carchi and esmeraldas provinces province in northwestern ecuador where it is an abundant local endemic. the remarkable long wooly trichomes in combination with a fruit dehiscing by a single dorsal slit and epiphytic habit differentiate Kohleria hypertrichosa from other species of Kohleria.
Cantón Archidona, Reserva Ecológica Antisana, comunidad Shamato, entrada por Km 21-Shamato, camino Sardinas-Shamato, 00u449S, 77u489W, 1700 m
  • Ecuador Paratypes
  • Napo
Paratypes. ECUADOR. Napo: Cantón Archidona, Reserva Ecológica Antisana, comunidad Shamato, entrada por Km 21-Shamato, camino Sardinas-Shamato, 00u449S, 77u489W, 1700 m, 28 Apr. 1998 (fl.), J. L. Clark, E. Narvaez & P. Mamallacta 5308 (MO, QCNE, UNA, US);
Bloque 19, línea 30 (Compañ ía Triton), 00u539S, 77u339W
  • Cantón Archidona
Cantón Archidona, Parque Nacional Sumaco Napo-Galera, Cordillera de Galeras, Bloque 19, línea 30 (Compañ ía Triton), 00u539S, 77u339W, 1400 m, 24 Apr. 1996 (fl.), E. Freire & J. Cerda 543 (MO, QCNE, US). PERU. Cajamarca: San Ignacio, San José de Lourdes, 00u599220S, 78u53930W, 2020 m, 23 Nov. 1999 (fl.), R. Vá squez & S. Flores 26324 (US).
IUCN Red List Categories and Criteria, Version 3.1. Prepared by the IUCN Species Survival Commission
  • Iucn
IUCN. 2001. IUCN Red List Categories and Criteria, Version 3.1. Prepared by the IUCN Species Survival Commission. IUCN, Gland, Switzerland, and Cambridge, United Kingdom.