Drymonia atropururea (Gesneriaceae), a new species from northwestern South America

Abstract

Recent expeditions to the western Andean slopes of Colombia and Ecuador and preliminary work on a revision of Drymonia (Gesneriaceae) have resulted in the discovery of a new species. The new species, Drymonia artropurpurea Clavijo & J.L. Clark, is distinguished from other congeners by large (up to 46 cm long) elliptic to oblong leaves, dark purple bullate calyces, and angulate (bent) corolla tubes.

Full text

DRYMONIA ATROPURPUREA (GESN ERIACE AE),
A NEW SPECIES FROM NORTHWESTERN SOUTH AMERICA
Laura Clavijo John L. Clark
Department of Biological Sciences, Box 870345 Department of Biological Sciences, Box 870345
The University of Alabama The University of Alabama
Tuscaloosa, Alabama 35487, U.S.A. Tuscaloosa, Alabama 35487, U.S.A
lvclavijoromero@crimson.ua.edu jlc@ua.edu
abstr act
Recent e xpeditio ns to the weste rn Andean sl opes of Colombia a nd Ecuador and p relimin ary work on a rev ision of Drymonia (Gesneriaceae)
have re sulted in the d iscover y of a new species . The new species , Drymoni a atropurpurea C lavijo & J.L. Cl ark, is dist inguishe d from other
congener s by large (up to 46 cm long ) elliptic to oblo ng leaves, dar k purple bull ate calyces, a nd angulate ( bent) corolla tu bes.
resumen
Expediciones recientes a la vertiente occidental de los Andes colombianos y ecuatorianos, y el trabajo preliminar de rev isión del género
Drymonia (Gesneriaceae) han permitido descubri r una nueva especie: Dr ymonia atropurpurea Clavijo & J.L. Clark, que se disting ue de
otra s especies d el género por sus hoj as grande s (hasta 46 c m de largo), de elíptica s a oblongas; por el c áliz púr pura oscuro y b ullado, y por el
tubo de l a corola angul ado (genicul ado).
Key Words: Gesneriaceae, Drymonia, t axonomy, Ecuador, Colombia
int roduction
The flowering plant family Gesneriaceae is a member of the order Lamiales (APG III 2009) and is primarily
pantropical with extensions into the subtropics and temperate regions (Weber 2004; Skog & Boggan 2006).
The family contains ca. 150 genera and ca. 3500 species and is classified into four major groups (Weber 2004).
In the Neotropics the highest concentration of species diversity for the family is found in Colombia with 32
genera and more t han 400 spe cies (Kvi st et al. 1998), followed by Ecuador w ith 29 genera and 240 species (Skog
& Kvist 1997), Brazil with 28 genera and 207 species (Forzza et al. 2010), and Peru with 28 genera and 150 spe-
cies (Kvist et al. 2005).
Drymonia, with 74 species, is the third largest genus of Gesneriaceae in the Neotropics, after Columnea
(272 species) and Besleria (200 species) (Weber 2004). It ranges from Mexico to Bolivia, including Brazil,
French Guiana, and the Caribbean. The highest species richness is found in Colombia with 31 species (Clavijo
& Clark 2008) and Ecuador with 30 species (Clark et al. 2006). Drymonia is a genus of terrestrial subshrubs,
vines or herbaceous epiphytes with campanulate, tubular or hypocyrotid flowers. Drymonia is especially di-
verse in the tropical wet forests along the western Andean slopes of southern Colombia and northern Ecuador
where there are over 35 species.
Drymonia has a wide range of morphological variation as a result of different pollinators and dispersal
mechanisms (Roalson et al. 2005; Clark et al. 2006). The morphological variation has made Drymonia a diffi-
cult genus to circumscribe. Ongoing studies on pollination biology have facilitated a better understanding of
the morphological variation that pertains to pouched flowers (bird pollinated) and campanulate flowers (eu-
glossine bee pollinated).
taxonomic t reatment
Drymonia atropurpurea Clavijo & J.L. Clark, sp. nov. (Fig. 1). type: ECUADOR. esmeraldas. Parroquia: Alto Tambo,
remn ant patch of prim ary forest on n orth side of road b etween Dura ngo and Alto Tambo on Hw y San Loren zo–Ibar ra, 0°57'59" N,
78°33'39" W, 695 m, 29 May 20 08 (fl, fr), J.L. Clark 10443 (holotype: US; isotypes: BRIT, K, MO, NY, QCNE, UNA).
Differs from other congeners by the subshrub habit, relatively large leaves to 46 cm long, dark purple inf lorescence bracts, bullate purple
dark c alyx, and ang ulate coroll a tube.
J. Bot. Res. Inst. Texas 6(1): 71 – 74. 2012

72 Journal of the Botanical Research Institute of Texas 6(1)
Fig. 1. Drymonia atropurpurea. A. Habit showing elongate unbranched stem. B. Immature fleshy bivalved capsule. C. Face view of corolla. D. Lateral
view of corolla showing angulation. (Photos A, C and D by J.L. Clark & B by L. Clavijo; A. J.L. Clark 7143; B. L. Clavijo 1689; C & D. J.L. Clark 10443).

Clavijo and Clark, A new species of Drymonia from northern South America
73
Terrestrial subshrub, 1–1.5 m tall. Stem erect, unbranched, quadrangular in cross–section, shallowly sulcate,
subwoody, green with red spots, glabrate basally, strigose apically, trichomes ca. 1 mm long, unbranched, yel-
low when dry; internodes (2.4–)5–15 cm long. Leaves opposite, decussate, equal in a pair; petioles 2.8–5.2 cm
long, terete, green with red spotting, base swollen with several pinkish gland–like enations, glabrate to strigil-
lose, str igose in the immature leaves, t richomes less than 1 mm long, yellow when dry; blade elliptic to oblong,
20–46 cm long, 6.3–21 cm wide, coriaceous, upper and lower surface green, sometimes lower surface green
suffused with light red, apex acuminate, base cuneate or sometimes slightly oblique, margin serr ulate, becom-
ing revolute when dr y, upper sur face glabrous, lower sur face glabrate; 6 –8 lateral pairs of vein s, venation raised
below, green when live, red–brown when dry, main vein strigose, secondary veins strigillose, higher order ve-
nation only evident abaxially, green when live, red–brown when dry. Inflorescence a reduced pair–flowered
cyme, 1 inflorescence per axil with 2–6 flowers; peduncle reduced to less than 1 mm long; inflore scence bracts
ca. 23 mm long, ca. 12 mm wide, dark purple, strigillose, elliptic, apex acute, margin entire; floral bract one,
10–23 mm long, 1–8 mm wide, dark purple, linear to spatulate, base decurrent, apex rounded, margin entire,
strigose to strigillose towards the apex; pedicel 16–32 mm long, red– orange, strigillose to str igose, glands scat-
tered along the pedicel. Calyx dark purple, coriaceous, bullate, persistent in fruit, apex rounded, margin en-
tire, base truncate to cordate, glabrate to strigose at the base, venation evident, the main vein strongly raised
abaxially, strigose; calyx lobes 5, 4 nearly equal, 5th lobe (dorsal) slightly smaller, lobes fused at the base for
2–4 mm, ventral lobes 18–25 mm long, 14–21 mm wide, rotund, margin occasionally involute, lateral lobes
19–28 mm long, 13–17 mm wide, ovate, margin involute apically, dorsal lobe 14–19 mm long, 8–13 mm wide,
ovate. Corolla zygomorphic, funnelform; corolla tube strongly angulate (bent) at the base, posture perpen-
dicular relative to the calyx, ca. 29 mm long, outer surface beige ventrally with some darker longitudinal lines,
red–brown dorsally, glabrous; corolla base ca. 7 mm wide, spur ca. 11 mm long, ca. 8 mm wide, white; throat
ca. 14 mm wide, light yellow, glandular trichomes on the inner surface; corolla lobes 5, subequal, red–brown,
apex obtuse, margin fimbriate, glabrous, ventral lobe longer than the other four lobes, spreading, ca. 13 mm
long, ca. 15 mm wide, orbicular, upper lobes reflexed, 6 mm long, 6 –7 mm wide, orbicular, lateral lobes re-
flexed, 9–10 mm long, 8 –9 mm wide, rotund. Androecium of 4 stamens, didynamous, 24–28 mm long, adnate
to the corolla tube for 9–10 mm, glabrous, staminode absent; anthers oblong, dehiscence by basal pores that
develop into longitudinal slits, 6–7 mm long, 1.5–2 mm wide. Gynoecium with a single dorsal nectary gland,
ovate, emarginate, 2.0 –2.6 mm long; ovary superior, ca. 6 mm long, ca. 4 mm wide, glabrous, oblong, laterally
compressed; style ca. 13 mm long, strigillose; stigma stomatomorphic, ca. 3 mm diameter. Fruit a bivalved
laterally compressed fleshy capsule, ca. 18 mm long, ca. 14 mm wide, rounded, externally red–brown with yel-
low patches towards the apex and the base, glabrous; seeds numerous, immersed in a mass of fleshy funicular
tissue, 0.4–0.6 mm long, 0.2–0.3 mm wide, brown when dry, rhombic, covered by a transparent aril.
Distribution and habitat.—Drymonia atropurpurea is known from wet forests on the western slopes of the
Andes in northern Ecuador and southern Colombia, between 350 and 1400 meters. In Colombia it has been
found in the understory of protected cloud forests that are part of the Río Ñambí Natural Reserve in the
Department of Nariño above 1000 meters. In northern Ecuador D. atropurpurea has been collected in remnant
patches of wet forest between 350 and 695 meters in the Esmeraldas Province along the San Lorenzo–Ibarra
highway.
Drymonia atropurpurea is distinguished from other congeners by the subshrub habit; large elliptic to ob-
long leaves to 46 cm long; dark purple bracts (inflorescence and floral) and calyces (Fig. 1A); bullate calyx
lobes; corolla tube strongly angulate (bent) at the base (Fig. 1D); corolla posture perpendicular relative to the
calyx; and dark redd ish–brown corolla lobes. Drymonia atropur purea is simila r to Drymonia turrialvae because
of their large leaves, relatively large funnelform corollas, and similar inflorescence. The two species are differ-
entiated by the subshrub habit in D. atropurpurea in contrast to the herbaceous habit in D. turr ialva e; the non–
bullate leaves with the abaxial surface green in D. atropurpurea in contrast to the bullate leaves with the abaxi-
al surface wine-red in D. tur rialva e; and a laterally compressed fleshy capsule in D. atropurpurea (Fig. 1B) in
contrast to a globose indehiscent berry in D. t urri alvae.

74 Journal of the Botanical Research Institute of Texas 6(1)
Etymology.—The specific epit het is Latin for dark purple: atro (=black), purpurea (=purple), in reference to
the dark purple color of the bracts and calyx.
Conservation and IUCN Red List category.—Drymonia atropurpurea is known from recently documented
populations in Ecuador and Colombia. The population in Colombia is from the well-established protected
area, Río Ñambí Natural Reserve (Nariño). The population from Ecuador is from an area that is almost com-
pletely deforested along the San Lorenzo–Ibarra highway. According to the IUCN Red List criteria for esti-
mated range, area of occupancy and population size (IUCN 2001), and considering the uncertain future of
habitat conservation in Ecuador, Drymonia atropurpurea should be listed in the category NT (Nearly
Threatened).
paratypes. COLOMBIA . Nariño: Mun icipio Barba coas, Corre gimiento A ltaquer, vered a El Barro. R eserva Nat ural Río Ña mbí, Sendero h acía
el río Ñambí. 1180–1400 m, 26 Jul 2011 (fr), L. Clavijo, M. Flores & A. Vásquez 1689 (COL, PSO). ECUADOR. Esmeraldas: Parroquia San
Loren zo, Cantón Alto Tam bo, Border region o f Awá Indigenous Terr itory, entranc e to the Río Bogot á communit y (future biologic al resea rch
stati on), near Q uebrada Pambi lar, 350–6 00 m, 0º58’57” N, 78 º35’50” W, 12 Feb 2003 (fl, fr), J.L. Clark 7145 (QCNE, SEL , UNA, US).
acKnoWl edgm ents
Support for this study was provided by the National Science Foundation (DEB–0841958 & DEB–0949169 to
JLC) and the Nellie Sleeth Scholarship from The Gesneriad Society, Inc. (to LC). We thank Alain Chautems,
Chri stian Feuillet, A lejandro Zuluaga and Steve Gi nzbarg for providi ng helpful reviews; the Herbario Nacional
Colombiano (COL) for access to their collections; and the Fundación Ecológica los Colibríes de Altaquer
(FELCA), especi ally Alex Vásquez and Mauricio Flores, for log istical support for the 2011 exp edition to the Río
Ñambí Natural Reserve in Nariño (Colombia).
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