Drymonia betancurii Clavijo & J.L. Clark, 2015

Clavijo, Laura & Clark, John L., 2015, Drymonia betancurii (Gesneriaceae), a new species from northwestern Colombia, Phytotaxa 221 (1), pp. 77-82 : 78-81

Drymonia betancurii Clavijo & J.L. Clark , sp. nov. ( Figs. 1 & 2 )

Diagnosis: Differs from other species of Drymonia by the presence of papillose-hispid trichomes on upper leaf surface and pitted on the lower surface; upper leaf surface dark green, often covered with white spots; calyx lobes densely pilose on both surfaces; corolla limb orange-red with white to yellow lobe margins; style with glandular trichomes.

Type:— COLOMBIA. Antioquia: Municipio Frontino, Parque Nacional Natural Las Orquídeas, vereda Venados Abajo, sector de Venados, sitio Arenales. 6º32’25.2”N, 76º18’38.7”W, 950–1000 m, 26 July 2011 (fl), J. Betancur, P. Pedraza-Peñalosa, M.F. González, R. Arévalo, D. Sanín, A. Zuluaga, J. Serna & A. Duque 15434 (holotype COL!, isotypes HUA!, NY!).

Herb, subshrub, or liana; terrestrial, hemiepiphyte, or epiphyte. Stem prostrate, scandent or appressed to tree, herbaceous to subwoody, with adventitious roots, branched, subquadrangular in cross-section, 2.5–3.9 mm in diameter, scarcely pilose to pilose basally, pilose to lanate apically; trichomes whitish, 1–2 mm long, unbranched; internodes 4.4–10.2 cm long. Leaves opposite, evenly spaced, decussate, subequal in a pair; petiole 0.5–2.5 cm long, terete in cross-section, green, with a gland at the base, densely pilose to lanate, trichomes 0.8–1.6 mm long; blade ovate to oblong, 3.1–8.1 × 2.5–6.0 cm, cartaceous, upper surface dark green, usually with white spots along the veins and sometimes with the venation light green, lower surface purple with light green venation, apex acuminate, base rounded to truncate, usually oblique, margin crenate to serrulate, upper surface papillose-hispid, lower surface pitted; 5–6 (–7) pairs of secondary veins, only evident abaxially, main vein sparsely pilose adaxially, densely pilose abaxially, secondary veins glabrate adaxially, densely pilose abaxially, higher order of venation only evident abaxially, pilose. Inflorescence reduced to an axillary solitary flower; bracts absent; flowers protandrous. Pedicel perpendicular or oblique relative to stem, 8–29 mm long, green, densely pilose. Calyx green to green suffused with red, membranous, venation conspicuous; calyx lobes 5, 4 nearly equal, dorsal lobe slightly reduced, free to nearly free, when nearly free fused at base for 2–5 mm, apex acute, base rounded to truncate, margin serrate, reflexed when in bud, pilose, dense at base on both surfaces; ventral and lateral lobes 13–26 × 7–18 mm, rhombic, ovate or oblong, dorsal lobe 12–19 × 6–13 mm, ovate to oblong. Corolla zygomorphic, 4.7–5 cm long, oblique to perpendicular relative to calyx, infundibuliform; tube constricted at base, 2.8– 3.2 cm long, 1.3–1.6 cm wide, outer surface white, sometimes pink ventrally, pilose, inner surface orange-red; base gibbous, 6– 5 mm in diameter, gibbosity 6–7 mm long; throat 17–19 mm in diameter, outer surface white and pilose, inner surface orange-red with short glandular trichomes dorsally; corolla lobes subequal, orange-red, margin white to yellow, 9–12 × 9–14 mm, orbicular, apex rounded, margin slightly erose, glabrous, ventral lobe slightly larger, lateral and dorsal lobes spreading, sometimes reflexed. Androecium of 4 stamens, didynamous, filaments 26–32 mm long, adnate to the corolla tube for 13–15 mm, white, glabrous, coiling after anthesis; staminode absent; anthers oblong, coherent by the lateral walls, dehiscence by basal pores that develop into longitudinal slits, 6–7 × 2–3 mm. Gynoecium with a single dorsal nectary gland, ovate, apex acute, 2–3 mm long, glabrous; ovary superior, 5–6 × 4–5 mm, ovate, orange, sericeous; style 17–19 mm long with sparse glandular trichomes, stigma stomatomorphic. Fruit not observed.

Distribution and habitat:— Drymonia betancurii is endemic to Colombia and is only known from the Pacific slopes of the Cordillera Occidental in the departments of Antioquia and Chocó, between 480 and 1000 m. Drymonia betancurii grows in scattered populations in open areas that are often near forest edges or in the shade of intact forests.

Phenology:—Flowers recorded from March to July; fruits not seen.

Etymology:—This species is named in honor of the Colombian botanist Julio Betancur, expert on Bromeliaceae and Heliconiaceae of Colombia, who has made monumental contributions to the knowledge of Colombian flora and has mentored several generations of Colombian botanists.

Additional specimens examined (paratypes):— COLOMBIA. Antioquia: Municipio Frontino, Corregimiento de Encarnación, Parque Nacional Natural Las Orquídeas , sector Venados , bosques cercanos a la cabaña de Parques Nacionales, 11 April 2011, J. Betancur, P. Pedraza-Peñalosa, J. M. Vélez-Puerta, A. Orjuela & A. Duque 15165 ( COL!, HUA!, NY!) ; Parque Nacional Natural Las Orquídeas, sector Venados, vereda Venados Abajo , sitio La Esperanza , cuenca de la quebrada Arenales , 6º42’6.8’’N, 76º18’46.03’’W, 880–920 m, 29 July 2011, P. Pedraza-Peñalosa, J. Betancur, M. F. González, R. Arévalo, D. Sanín, A. Zuluaga, A. Duque & J. Serna 2443 ( COL!, NY!) ; Parque Nacional Natural Las Orquídeas, sector Venados, vereda Venados Abajo , sitio La Esperanza , cuenca de la quebrada Arenales , 6º42’6.8’’N, 76º18’46.03’’W, 880–920 m, 20 July 2011, P.Pedraza-Peñalosa, J.Betancur, M. F. González, R. Arévalo, D. Sanín, A. Zuluaga, A. Duque & J. Serna 2486 ( COL!, NY!, UNA!) ; vereda Cruces, sitio Piñares, camino a Perdidas , poco después de la escuela La Esperanza , orilla izquierda del río Calles , Parque Nacional Natural Las Orquídeas , bosque poco perturbado, 6º28’35.5’’N, 76º19’39.5’’W, 980 m, 3 May 2013, S. E. Hoyos-Gómez, J. Betancur, R. Arévalo, M. F. González, M. S. Jaimes, F. Gómez, A. Duque, C. Rivera, W. Quinceno & F. Pino 2289 ( COL!, NY!) ; Municipio Urrao, vereda Cruces, camino al río Penderisco desde la escuela La Esperanza , alrededores de la quebrada La Balsora , márgen izquierda del río Calles , Parque Nacional Natural Las Orquídeas , bosque al lado de una quebrada y potrero al lado del camino, 6º27’58’’N, 76º19’19.11’’W, 880–900 m, 7 May 2013, J. Betancur, R. Arévalo, S. E. Hoyos-Gómez, M. S. Jaimes, A. Duque, W. Quinceno & F. Pino ( COL!, NY!). Chocó: Along road from Quibdó to Tutunendo , 1 hour past Tutunendo , vereda 21, at Alto de Veinte , hacienda of Ruben Jaramillo, 1/2 hour walk down hill from roadside ; rain forest 18 km NE of Tutunendo, 480 m, 15 March 1987, H. Wiehler 8730 B ( SEL!) .

Drymonia betancurii is similar to D. variegata Uribe (1952: 1) , but they are readily differentiated when fertile. The two species are similar in their diverse habits and foliage (e.g., dark green, papillose-hispid trichomes on upper blade surface, and pitted and purple lower blade surface). Drymonia betancurii is differentiated from D. variegata by the presence of white spots on the upper surface, although, at least one population of D. betancurii have light green venation and lack white spots. When sterile, the non-spotted populations of D. betancurii are similar to D. variegata . The two species are differentiated by the following characters in D. betancurii : petiole 0.5–2.5 cm long (vs. ca. 5 cm long); blades ovate to oblong to 8.1 cm long (vs. lanceolate to elliptic to 15.2 cm long); calyx lobes rhombic, ovate or oblong, 7–18 mm wide (vs. lanceolate, 1–6 mm wide); and corolla lobes orange with white to yellow margin (vs. white with maroon or purple lines). Drymonia variegata is widely distributed from Panama to Ecuador, while D. betancurii is restricted to the Pacific slopes of the Colombian Andes in the departments of Antioquia and Chocó, where these two species are sympatric. Hans Wiehler and the Gesneriad Research Foundation team made the first known collection of D. betancurii (H. Wiehler 8730B) during their expedition to Colombia in 1987, and although they noticed the unusual white spots on the leaves they identified the collection as D. variegata ( Milewiski 1987) .

Drymonia betancurii and Drymonia droseroides J.L. Clark & Clavijo (2010: 190) are similar because of their dark green and bullate foliage. The two species are differentiated by the following characters in D. betancurii : habit of prostrate herb, liana, epiphyte or hemiepiphytic shrub (vs. terrestrial shrub); petioles 0.5–2.5 cm long (vs. 6–7.7 cm long); leaves 3.1–8.1 × 2.5–6.0 cm (vs. 16.5–21.1 × 11.6–13 cm); calyx lobes rhombic, ovate or oblong and pilose (vs. spatulate with glandular hairs); and an infundibuliform corolla with an orange-red limb (vs. campanulate with limb yellow to pink).

The stem indument and the habit of D. betancurii are similar to D. alloplectoides Hanstein (1865: 358) . However, D. betancurii is differentiated by dark green, papillose-hispid leaves (vs. green, villous), calyx serrate (vs. entire), corolla lobes orange-red with the margin white to yellow (vs. white), and ventral corolla lobe slightly erose (vs. fimbriate).

Figures

FIGURE 1. Drymonia betancurii. A. Lower leaf surface. B. Upper leaf surface with inset showing the papillose-hispid indument. C. Lateral view of flower.D. Lateral view of flower showing androecium and gynoecium. E. Gynoecium showing single dorsal nectary gland, glandular trichomes on style, and stomatomorphic stigma. F. Habit. (from the holotype, J. Betancur 15434, and P. Pedraza-Peñalosa 2443).

FIGURE 2. Drymonia betancurii. A–B. Habit. C. Lateral view of flower. D. Upper leaf surface. E. Front view of flower. F. Front view of flower showing anthers and glandular hairs. G. Anther (from P. Pedraza-Peñalosa 2443).