Pleurothallis chicalensis, a new species in subsection Macrophyllae-Fasciculatae (Orchidaceae: Pleurothallidinae) from northwestern Ecuador

Abstract

Resumen. Una especie nueva de Pleurothallis de la subsección Macrophyllae-Fasciculatae de Ecuador es descrita, ilustrada y su afinidad con otras especies es discutida. Pleurothallis chicalensis se compara con P. dewildei, de la cual difiere por las hojas ovadas, las flores amarillas con el sinsépalo ampliamente obovado y el labelo transversalmente cordado con el ápice apiculado. Abstract. A new species of Pleurothallis in subsection Macrophyllae-Fasciculatae from Ecuador is described, illustrated and its relationship with other species is discussed. Pleurothallis chicalensis is compared with P. dewildei, from which is distinguished by the ovate leaves, the yellow flowers with broadly obovate synsepal and the transversely cordate lip with apiculate apex.

Full text

LANKESTERIANA 18(2): 103–109. 2018.
PLEUROTHALLIS CHICALENSIS, A NEW SPECIES
IN SUBSECTION MACROPHYLLAE-FASCICULATAE (ORCHIDACEAE:
PLEUROTHALLIDINAE) FROM NORTHWESTERN ECUADOR
Marco M. JiMénez1,2,4,*, Luis e. Baquero2,3, Mark WiLson5 & GaBrieL a. iturraLde3
1 Avenida del Ejército y Juan Izquierdo, Zamora, Zamora Chinchipe, 190102, Ecuador
2 Jardín Botánico de Quito, Pasaje #34, Rumipampa E6-264 y Av Shyris, Interior Parque La Carolina,
Quito, 170506, Ecuador
3 Carrera de Ingeniería Agroindustrial y Alimentos. Facultad de Ingeniería y Ciencias Agropecuarias,
Universidad de Las Américas, Calle José Queri, Quito, Pichincha, 170137, Ecuador
4 Instituto Nacional de Biodiversidad, Pasaje Rumipamba 341 y Avenida de los Shyris, Quito,
Pichincha, 170135, Ecuador
5 Department of Organismal Biology and Ecology, Colorado College, Colorado Springs,
CO 80903, USA
* Author for correspondence: mmjimenez473@gmail.com
aBstract. A new species of Pleurothallis in subsection Macrophyllae-Fasciculatae from Ecuador is described,
illustrated and its relationship with other species is discussed. Pleurothallis chicalensis is compared with P.
dewildei, from which is distinguished by the ovate leaves, the yellow owers with broadly obovate synsepal and
the transversely cordate lip with apiculate apex.
resuMen. Una especie nueva de Pleurothallis de la subsección Macrophyllae-Fasciculatae de Ecuador es
descrita, ilustrada y su anidad con otras especies es discutida. Pleurothallis chicalensis se compara con P.
dewildei, de la cual diere por las hojas ovadas, las ores amarillas con el sinsépalo ampliamente obovado y el
labelo transversalmente cordado con el ápice apiculado.
key Words: Andes, Carchi, Pleurothallis bovilingua, Pleurothallis dewildei, taxonomy
Received 22 January 2018; accepted for publication 31 May 2018. First published online: 20 July 2018.
Licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Costa Rica License
doi: https://doi.org/10.15517/lank.v18i2.34050
Introduction. In the genus Pleurothallis R.Br.
sensu Pridgeon et al. (2005) there are between 478
and 625 species (Wilson unpubl. data), depending
on synonymy, making it the third largest genus in
Pleurothallidinae, after Lepanthes Sw. and Stelis Sw.
The genus is distributed from Central America and the
Caribbean Islands to South America, where most of
the species are epiphytes in cloud forests of the Andes
(Doucette et al. 2016).
Section Macrophyllae-Fasciculatae Lindl.
was created as part of Pleurothallis infrageneric
classication by Lindley (1859), which was later
considered by Luer (1986) in his initial systematics
of genus Pleurothallis and subsequently demoted to a
subsection of the same name (Luer 1988). However,
in 2005 he resurrected the genus Acronia C.Presl,
grouping the subsections Acroniae (C.Presl) Luer and
Macrophyllae-Fasciculatae (Lindl.) Luer (Luer 2005).
Recently, phylogenetic relationships of
Pleurothallis have been evaluated from DNA
sequence analysis (Pridgeon et al. 2001, Wilson et
al. 2011, 2013, unpubl. data). The studies revealed
the close relationship of subsection Macrophyllae-
Fasciculatae with the type species Pleurothallis
ruscifolia (Jacq.) R.Br. that supports the inclusion
of this group within Pleurothallis versus Acronia
(Wilson et al. 2016).
Luer (2005) in revision of subsection
Macrophyllae-Fasciculatae indicated that members
of the group are distinguished by their sessile leaves
with a cordate base, single owers with lateral sepals
connate into a synsepal, and a bilobed stigma. Since

LANKESTERIANA 18(1). 2018. © Universidad de Costa Rica, 2018.
104 LANKESTERIANA
Luer’s revision, about a dozen new species have
been described in this group, bringing the number
to between 236 and 305 species, depending on
synonymy (Wilson unpubl. data).
Northwestern Ecuador has been the source of
several new orchid discoveries in the recent years.
Exhaustive exploration carried out in the forests of
El Carchi Province, near the Colombian border has
resulted in the discovery of species like Porroglossum
raoi Baquero & Iturralde and Platystele baqueroi
Jost & Iturralde. In 2016, Luis Baquero found an
unknown species of Pleurothallis from subsection
Macrophyllae-Fasciculatae in this area. This species
with intense, yellow owers and cordate lip is
described here.
taxonoMy treatMent
Pleurothallis chicalensis M. Jiménez & Baquero, sp.
nov. (Fig. 1, 2A–B).
TYPE: Ecuador: El Carchi Province, near Cerro
Colorado, Chical-El Carmen road, 00°54.74’N,
78°12.34’W, 1590 m, 4 June 2016, LB 3033 (holotype,
QCNE!).
diaGnosis: Similar to Pleurothallis dewildei Luer &
R. Escobar, from which it differs in the ovate leaves,
the yellow owers with broadly obovate synsepal
and the widely cordate, apiculate lip with involute
margins versus the narrowly ovate leaves, purple
owers with ovate synsepal and the broadly cordate-
ovate lip with obtuse, saccate apex of P. dewildei.
Plant medium in size, ca. 20 cm tall, epiphytic,
caespitose. Roots numerous, slender ca. 1 mm
wide. Ramicauls green, erect, slender, 10–30 cm
long, enclosed by a tubular, brown sheath running
through the second third from the base, and 1–2
other tubular sheaths near the base. Leaf green
above, microscopically papillate, dull, light green
underneath, perpendicular to the ramicaul, coriaceous,
ovate, acuminate, 7–18 × 4–8 cm, edge entire, the
base sessile, deeply cordate, with lobes connate for
1 cm. Inorescence a solitary ower, resupinate,
produced successively from a reclining spathaceous
bract ca. 1 cm long; peduncle ca. 3–5 mm long
concealed within the spathe, oral bract 3 × 2 mm,
pedicel ca. 6 mm long. Ovary 5 mm long, clavate,
almost straight. Flower 20–23 × 13–18 mm, bright-
yellow. Sepals glabrous to microscopically papillose;
dorsal sepal ovate, 12–13 × 8 mm, 9-veined, obtuse,
margin microscopically glandulous; synsepal broadly
obovate, 10–11 × 8–9 mm, 10-veined, subacute,
margin microscopically papillous. Petals obliquely
triangular-ovate, acute, 7–8 × 2.0–2.5 mm, 3-veined.
Lip broadly cordiform, obtuse with a minute rounded
apiculus, 4 × 4–5 mm, 5-veined, with involute
margins starting near the middle towards the apex,
microscopically pubescent; the base subtruncate with
a short, deexed claw, hinged to the column-foot;
glenion a small depression between the basal lobes
of the lip, surrounded by a slightly convex disc,
thickened to the sides. Column stout, yellow-green,
2.0 × 1.6 mm, stigma bilobed. Anther cap apical,
yellow, narrowly deltoid. Pollinia 2, narrowly ovoid.
ParatyPe: Cerro Oscuro, near Chical, 00°54.445’N,
78°11.63’W, 1499 m, 29 October 2016, Baquero 3065
(paratype: QCNE!, owers preserved in alcohol).
ePonyMy: Named after Chical, a small town in El
Carchi Province of Ecuador close to the type locality.
distriBution and haBitat: Pleurothallis chicalensis
has been found in two localities, close to Cerro
Colorado on the Chical-El Carmen road and in
Cerro Oscuro near the small town of Chical (Fig.
3). Two individuals were found growing at the type
locality and a population of fteen plants was found
at the second locality. It was also found around La
Planada Natural Reserve, Department of Nariño in
southwestern Colombia (Fig. 3), based on a color
photograph in the book Orquídeas en la Niebla
(Orejuela 2011). The color and morphology of
owers is consistent between populations.
Pleurothallis chicalensis is sympatric with
P. imperialis Luer and P. crucifera Luer & Hirtz,
two species conned to northwestern Ecuador. In
Cerro Oscuro it is also found with Scaphosepalum
swertiifolium (Rchb.f.) Rolfe, S. cimex Luer & Hirtz
and other pleurothallids. Near Cerro Colorado, it is
found growing next to P. imperialis, P. crucifera,
Sobralia lancea Garay, S. crocea (Poepp. & Endl.)
Garay, S. macrophylla Rchb.f. and S. ecuadorana
Dodson.

JiMénez et aL. — P. chicalensis from Ecuador 105
LANKESTERIANA 18(1). 2018. © Universidad de Costa Rica, 2018.
conservation status: Both Ecuadorian localities are
near the Colombian border, however, the plants at the
type locality are threatened by road works, while the
population of Cerro Oscuro is protected in Ecominga’s
FiGure 1. Pleurothallis chicalensis Jiménez & Baquero A. Habit. B. Dissected ower. C. Flower close-up. D. Column and lip,
lateral view. Illustration by Luis Baquero based on the holotype.

Dracula Reserve. The status of the population near La
Planada in Nariño, Colombia is unknown. Until further
assessment can be performed, the species should be
considered “data decient” (DD) under IUCN criteria.
Discussion. Due to morphology and geographic
proximity, P. chicalensis is probably most closely
related to P. dewildei (Fig. 2C–D, 4–5), P. bovilingua
Luer & R. Escobar (Fig. 4–5), and P. calolalax Luer &
LANKESTERIANA 18(2). 2018. © Universidad de Costa Rica, 2018.
106 LANKESTERIANA
FiGure 2. Pleurothallis chicalensis ower (A) and lip (B), and Pleurothallis dewildei ower (C) and lip (D). Photos by Andreas Kay
(A–B), Sebastian Vieira-Uribe (C) and Mark Wilson (D).

R. Escobar (Fig. 5). The vegetative and oral features
shared are the unusually wide, obliquely triangular
petals and the wide lip, which is remarkable in species
of Macrophyllae-Fasciculatae subsection. However,
P. chicalensis is easily recognized in this group of
species inside the subsection, by the uniformly bright
yellow owers and the broadly cordate shape of the
lip. Other signicant differences between these species
are detailed in the Table 1.
Both P. chicalensis and P. dewildei occur in the
Pacic slopes of the Andes (Fig. 3). The type locality
for P. dewildei is south of Pueblo Rico, Risaralda,
Colombia, on the Pacic slope of the Western
Cordillera (Luer 1998) (Fig. 3). Unfortunately, P.
bovilingua was described without collection data.
acknoWLedGMents. We acknowledge to Universidad de Las
Américas (UDLA) for funding research on orchids of Ecuador.
The Ministerio del Ambiente is acknowledged for issuing
Environmental Research Permit 008-2016-IC-FLO-DNB/MA.
We also want to thank Andreas Kay and Sebastian Vieira for
giving us permission to use their photos.
JiMénez et aL. — P. chicalensis from Ecuador 107
LANKESTERIANA 18(2). 2018. © Universidad de Costa Rica, 2018.
FiGure 4. Drawings of A. Pleurothallis dewildei and B. Pleurothallis bovilingua (Reproduced from Luer (2005) courtesy of
Missouri Botanical Garden Press).
FiGure 3. Distribution of Pleurothallis chicalensis (white stars)
in Ecuador and Colombia and P. dewildei (black star) in
Colombia.

Literature cited
Doucette, A., Wilson, M., Portilla, J., Kay, A., Moreno, J.
S. & Cameron, K. M. (2016). Dos especies nuevas de
Pleurothallis y un nuevo nombre para Acronia rinkei.
Orquideología, 33(2), 123–139.
Luer, C. A. (1986). Icones Pleurothallidinarum III:
Systematics of Pleurothallis. Monographs in Systematic
Botany from Missouri Botanical Garden, 20, 1–57.
Luer, C. A. (1988). A revision of some sections of subgenus
Pleurothallis. Lindleyana, 3(3), 133–149.
Luer, C. A. (2005). Icones Pleurothallidinarum XXVII:
Dryadella and Acronia section Macrophyllae-
Fasciculatae. Monographs in Systematic Botany from
Missouri Botanical Garden, 103, 1–311.
Luer, C. A. & Escobar, R. (1998). Nuevas especies de
Pleurothallis de Colombia. Orquideología, 21(1), 72–
108.
Orejuela Gärtner, J. E. (2011). Orquídeas en la niebla. Cali,
Colombia: Universidad Autónoma de Occidente.
Pridgeon, A. M., Solano, R. & Chase, M. W. (2001).
Phylogenetic relationships in Pleurothallidinae
(Orchidaceae): Combined evidence from nuclear and
plastid DNA sequences. American Journal of Botany,
88(12), 2286–2308.
Pridgeon, A. M., Cribb, P. J., Chase, M. W. & Rasmussen
F. N. (2005). (Eds.). Genera Orchidacearum. V. 4:
Epidendroideae (Part 1). Oxford: Oxford University
Press.
Wilson, M., Belle, C., Dang, A., Hannan, P., Kenyon,
C., Low, H., Stayton, T. & Woolley, M. (2011). A
phylogenetic analysis of the genus Pleurothallis, with
emphasis on Pleurothallis subsection Macrophyllae-
Fasciculatae, using nuclear ITS and chloroplast DNA
LANKESTERIANA 18(2). 2018. © Universidad de Costa Rica, 2018.
108 LANKESTERIANA
FiGure 5. Lip drawings. A. Pleurothallis chicalensis, frontal
view. B. Pleurothallis dewildei, frontal, lateral and
ventral view. C. Pleurothallis calolalax, frontal, lateral
and ventral view. D. Pleurothallis bovilingua, frontal
and lateral view. (Modied from Luer (2005) courtesy
of Missouri Botanical Garden).
Plant part P. chicalensis P. dewildei aP. bovilingua a
Leaves Ovate, 7–18 × 4–8 cm Narrowly ovate, 10–15 × 3.0–4.5
cm
Narrowly cordate-ovate, 9–20 ×
2.5–5.0 cm
Flowers Bright yellow Purple, dorsal sepal purple to
yellow Light rose-brown, lip darker
Synsepal Broadly ovate, obtuse, 10–11
mm × 8–9 mm
Ovate, subacute synsepal, 17 ×
12 mm
Ovate, acute, 24–25 mm × 17.0
mm, 8-veined
Lip
Broadly cordiform, 4 × 4–5
mm, 5-veined, with involute
margins, apiculate
Broadly cordate-ovate, 6.0 × 5.5
mm, apparently 3-veined, concave
with involute margins above the
middle, obtuse
Ovate, 7 × 6 mm, apparently not
veined, acute, incurved
a Obtained from Luer (1998).
taBLe 1. Comparison of Pleurothallis chicalensis to P. dewildei and P. bovilingua.

sequencing. Lankesteriana, 11(3), 369.
Wilson, M., Belle, C., Dang A., Hannan, P., Kellogg, L.,
Kenyon, C., Low, H., Mochizuki, A., Nguyen, A.,
Sheade, N., Shan, L., Shum, A., Stayton, T., Volz, C.,
Vosburgh, B., Wellman, H. & Woolley, M. (2013).
A preliminary phylogenetic analysis of Pleurothallis
sensu lato based upon nuclear and plastid sequences.
Lankesteriana, 13(1–2), 139.
Wilson, M., Baquero, L., Dupree, K., Jiménez, M. M.,
LeBlanc, C. M., Merino, G., Portilla, J., Salas Guerrero,
M., Tobar Suárez, F., & Werner, J. D. (2016). Three new
species of Pleurothallis (Orchidaceae: Pleurothallidinae)
in subsection Macrophyllae-Fasciculatae from northern
South America. Lankesteriana, 16(3), 349–350. https://
dx.doi.org/10.15517/lank.v16i3.27314
JiMénez et aL. — P. chicalensis from Ecuador 109
LANKESTERIANA 18(2). 2018. © Universidad de Costa Rica, 2018.

LANKESTERIANA 18(2). 2018. © Universidad de Costa Rica, 2018.
LANKESTERIANA