Columnea combeimae Lozano-Cif., J. E. Ríos & J. L. Clark, 2025

Clark, John L., Lozano-Cifuentes, David, Ríos-Cervera, Jorge, Clavijo, Laura & Ballesteros, Sofía, 2025, Two new species of Columnea (Gesneriaceae) from the Colombian Andes, PhytoKeys 261, pp. 317-328 : 317-328

Columnea combeimae Lozano-Cif., J. E. Ríos & J. L. Clark sp. nov.

Fig. 1

Type.

Colombia • Tolima: Ibagué, vereda Ancón, Tesorito, ruta de las tres cascadas , 4°28'49.19"N, 75°13'27.54"W, 1900 m, 21 Mar 2024 (fl.), D. Lozano-Cifuentes, J. Ríos & N. Romero 554 (holotype: SURCO! [accession 016300]; isotypes: SEL, JAUM) .

Diagnosis.

Columnea combeimae and C. fuscihirta share a dorsiventral epiphytic habit, elongate tubular yellow corollas, and conspicuous flowers lacking showy floral bracts. Columnea combeimae differs in having a uniformly green abaxial leaf surface (vs. abaxial surface with red apices in C. fuscihirta ), a glabrescent region at the base of the shoots (vs. shoots uniformly hirsute), and prominent nectary glands at the apex of the pedicel (vs. nectaries absent on the pedicel).

Description.

Facultative epiphytic herbs with dorsiventral shoots; stems terete in cross-section, 1.7–2.2 cm in diameter, glabrescent at the base and densely hirsute with dark purple trichomes toward the apex; internodes 0.8–3.6 cm long, leaf scars flush with the stem. Leaves opposite, anisophyllous, larger blade broadly lanceolate to oblong, 7.5–25 cm long, 3.5–7.0 cm wide, apex acuminate, base oblique, lateral veins 6–8 per side, adaxially uniformly dark green, abaxial surface uniformly light green with prominent purple midvein for lower third and otherwise green, abaxial leaf surface uniformly pilose to hirsute with multicellular purplish-colored trichomes, denser on veins, margin crenulate to serrulate; petioles (0.8 –) 1.0–1.8 (– 2.2) cm long, pilose with multicellular purplish-colored trichomes; smaller blade 0.7–1.5 cm long, 0.4–0.7 cm wide, lateral veins 1–3 per side, petiole 0.6–0.9 mm, otherwise similar to large blade. Inflorescence reduced to 1–3 axillary flowers; bracts inconspicuous, ovate, purple, 4–5 mm long, 4.2–4.6 mm wide, slightly acuminate apex. Flowers with pedicels 3–6 mm long, light green, densely pilose with multicellular gold-colored hispid indumentum. Calyx lobes green with purplish apices, 1.7–2.2 cm long, 0.7–1.1 cm wide at base, oblong, apex acuminate and reflexed; outer surface densely pilose to hirsute with multicellular purplish trichomes; inner surface glabrous; margin with at least two large laciniate projections per side. Corolla 3.2–4.1 cm long, 0.8–1.0 cm wide at widest point and 0.6–0.7 cm at base, tubular, lobes elliptic, tube 2.8–3.3 cm long, corolla lobes 0.4–0.5 mm long, rounded, slightly ampliated on lower surface, gibbous at base, uniformly yellow, outer surface densely pilose with multicellular gold-colored trichomes, inner surface of corolla tube with glandular trichomes. Androecium of 4 didynamous stamens, filaments glabrous, ca. 2.7–3.0 cm long, connate at base for 0.3–0.4 cm and adnate to corolla, anthers ca. 2.5–2.7 mm long, 1.9–2.1 mm wide, quadrangular. Gynoecium with nectary comprised of a single-lobed dorsal and two smaller lateral glands, ovary ca. 3.0– 4.5 mm long, globose, indument pilose; style 2.0– 2.6 cm long, glabrescent, stigma stomatomorphic. Fruits not observed.

Additional specimens examined.

Colombia – Tolima. • Ibagué: ruta sur al nevado del Tolima, entre lajas y tierra de gigantes , 4°22'23"N, 75°13'58.81"W, 3200 m, 21 Mar 2024 (fl.), D. Lozano-Cifuentes & M. Rincón 95 ( JBB [accession: 41534]) ; • Líbano , 4°54'10"N, 75°6'10"W, 2340 m, 7 Oct 2022 (fl.), J. Betancur et al. 23775 ( COL [accession: 628308]) ; • Murillo, vereda el agrado, km 7.5 vía Murillo, hostal Camino Viejo , 4.90220°N, 75.10281°W, 2169 m, 9 Oct 2022 (fl.), J. Aguirre-Santoro et al. 5059 ( COL [accession: 626998]) .

Phenology.

Plants were documented in flower during January to March and October to December.

Etymology.

The specific epithet refers to the Combeima Canyon (Cañón de Combeima), the type locality where the species was discovered.

Distribution and preliminary IUCN red list assessment.

Columnea combeimae is endemic to Colombia and known from only three collections in high Andean forests of the Cordillera Central, within the department of Tolima and the municipalities of Ibagué and Libano, at elevations between 2000 and 3500 m. Its extent of occurrence (EOO) is estimated at 35.8 km 2, and its area of occupancy (AOO) is estimated at 12 km 2. One locality occurs in a recently disturbed area of Parque Nacional Natural Los Nevados, while the other two are in forested areas with no formal protection.

The species is threatened by ongoing habitat loss and fragmentation resulting from deforestation, the expansion of agriculture (especially coffee plantations), livestock, and urbanization. These threats were recently observed by the authors and have led to a recent decline in the quality and extent of suitable habitat (subcriteria B 2 b (i, ii, iii) and B 1 b (i, ii, iii )). The EOO is within the threshold of Critically Endangered (<100 km 2) and the AOO is within the threshold of Endangered (<50 km 2). The number of known locations is three, which is within the threshold of Endangered (number of known locations <5). Columnea combeimae is preliminary assessed as Endangered (EN) under IUCN Red List criteria B 1 ab (i, ii, iii) + 2 ab (i, ii, iii).

Comments.

Columnea combeimae (Fig. 1 ) and C. fuscihirta (Fig. 2 ) are similar in having uniformly bright yellow tubular corollas (Figs 1 C , 2 C ) and inconspicuous or highly reduced bracts. In contrast, most species of Columnea have persistent brightly colored bracts that cover the calyx lobes and often the lower portion of the corolla tube. Both C. combeimae and C. fuscihirta share a dorsiventral epiphytic habit and pairs of anisophyllous leaves (Figs 1 B , 2 A ).

Columnea combeimae is distinguished from C. fuscihirta by the presence of a hirsute indumentum of purple trichomes near the shoot apex and glabrescent basally. In contrast, C. fuscihirta has a uniformly golden-yellow indumentum that is consistently hirsute at both the base and apex of the shoots. The abaxial leaf surface of C. fuscihirta is green with red apices (Fig. 2 B ), whereas in C. combeimae it is uniformly green (Fig. 1 A, B ). Additional diagnostic features of C. combeimae include a purple midvein on the lower surface of the leaf (vs. uniformly green in C. fuscihirta ) and prominent extrafloral nectary glands on the upper portion of the pedicel (Fig. 1 H ), which are absent in C. fuscihirta .

Figures

Figure 1. Columnea combeimae J. Lozano-Cif., J. E. Ríos & J. L. Clark. A. Habit; B. Abaxial and adaxial leaf surfaces; C. Lateral views of flower; D. Front view of corolla; E. Calyx lobes; F. Stigma and style; G. Floral bract; H, I. Gynoecium featuring nectaries; J. Androecium (A – I. from D. Lozano-Cifuentes et al. 554). Photos by David Lozano-Cifuentes.

Figure 2. Columnea fuscihirta L. P. Kvist & L. E. Skog. A. Habit; B. Abaxial leaf surface; C. Lateral view of flower; D. Gynoecium; E. Immature fruit; F. Front view of corolla (A, B. from Oscar Marin s. n. C – F. from J. L. Clark et al. 15808). Photos A, B. by Oscar Marin and C – F. by John L. Clark.