Columnea fluidifolia J.L.Clark & F.Tobar, 2022

Tobar, Francisco, Smith, James F. & Clark, John L., 2022, Two new pendulous epiphytic Columnea L. (Gesneriaceae) species from the Choco forests of the Northern Andes, PhytoKeys 196, pp. 49-61 : 49

Columnea fluidifolia J.L.Clark & F.Tobar sp. nov.

Figs 2 , 3

Type.

Ecuador. Pichincha: cantón Quito, parroquia Pacto, primary road between the town of Pacto and Mashpi Lodge , 0°9'49.3"N, 78°49'14.6"W, 1662 m, 15 Mar 2019, J.L. Clark & L. Jost 16286 (holotype: US; isotypes: ECUAMZ, QCA, SEL).

Diagnosis.

Similar to Columnea ceticeps , differing in calyx and corolla uniformly orange (vs. calyx green and corolla bright red in C. ceticeps ) and corolla shallowly bilabiate (vs. deeply bilabiate in C. ceticeps ).

Description.

Epiphytic herb with elongate pendent shoots, 1.0-1.5 m long, red-brown, with zigzag appearance, densely pilose with gold-colored multicellular trichomes; internodes 2.0-4.0 cm long. Petioles 0.2-0.4 cm long, pilose with multicellular trichomes; leaves opposite, pairs either strongly anisophyllous or isophyllous, sometimes anisophyllous and isophyllous on the same shoot, larger leaf 9.5-10.5 cm long, 3.9-4.5 cm wide, ovate-elliptic, apex long acuminate, base slightly oblique, lateral veins 5-8 per side, adaxially dark-green, with multicellular white-transparent trichomes, abaxially light-green, densely pilose with multicellular white transparent trichomes, more densely pubescent on veins, margin serrulate; smaller leaf 1.3-1.9 cm long, 0.2-0.3 cm wide, lateral veins 2-3 per side, petiole 0.1-0.2 cm long, otherwise similar to larger leaf. Inflorescence reduced to a single axillary flower; bracts not seen, presumably caducous. Pedicels 2.6-3.7 cm long, bright orange, densely pilose with multicellular rust-colored trichomes. Calyx loosely clasping corolla, uniformly bright orange, lobes 2.6-4.2 cm long, 0.4-0.6 cm wide, oblong to narrowly-elliptic, apex acuminate to obtusely acuminate, exterior pilose, with multicellular rust-colored trichomes, more pubescent on veins and margins, interior glabrous, margin serrulate. Corolla 4.5-4.9 cm long, 0.6-0.8 cm at widest point, tubular throughout, inflated near center, slightly gibbous at the base, 0.6-0.7 cm wide before the limb, 0.2-0.4 cm at narrowest point of the base, bright orange externally, densely pubescent with multicellular rust-colored trichomes, interior with short white trichomes; ventral and lateral lobes reflexed, ventral lobe narrowly triangular to oblong, 0.4-0.5 cm long 0.2-0.3 cm wide, dorsal lobes fused, 0.2-0.3 cm long, 0.4-0.5 cm wide, lateral lobes triangular to narrowly triangular, 0.2-0.3 cm long, 0.2-0.3 cm wide. Filaments ca. 4.5 cm long, connate at base for 0.3 cm and adnate to corolla, anthers ca. 1.0 mm long, 1.0 mm wide, included in the corolla throat, quadrangular. Ovary ca. 4.0 mm long, conical, densely pubescent, with multicellular transparent trichomes; style 3.5-4.0 cm long, white with yellow apex, glabrescent; stigma unlobed, papillate, included in corolla tube. Nectary a bilobed dorsal gland. Fruit an indehiscent succulent berry, globose, distally acuminate, uniformly white, pilose; seeds not seen.

Phenology.

Flowering during June, August, and November. Mature fruits observed in June.

Etymology.

The phyllotaxy in most neotropical Gesneriaceae is opposite with pairs that are either equal in size (isophyllous) or strongly unequal in size (anisophyllous). The leaves in C. fluidifolia are unusual for having anisophyllous leaf pairs (Fig. 2B ) and isophyllous leaf pairs (Fig. 2C ) on the same shoot. The specific epithet reflects the remarkable variability of this vegetative character in C. fluidifolia .

Distribution and preliminary assessment of conservation status.

Columnea fluidifolia is endemic to the northwestern Andean slopes of Ecuador. The only known populations are located in the Mashpi-Pachijal conservation area, in the northwestern province of Pichincha (Fig. 1 ). The Mashpi-Pachijal conservation area is located in the broadly defined ecoregion referred to as the Chocó Biogeographic Region or the Tumbes-Chocó-Magdalena biodiversity hotspot. According to the vegetation classification system by the Ecosystems of Continental Ecuador ( MAE 2012), the vegetation is classified as Bosque siempreverde piemontano de Cordillera Occidental de los Andes (BsPn01) (premontane evergreen forest) and represents a narrow band between 300 and 1400 meters, that ranges from the Esmeraldas province in the north to the Santo Domingo de los Tsáchilas province in the south. Most remnants of this vegetation have been converted to agriculture crops or livestock. Fewer than 40 individuals of C. fluidfolia are known, with a majority in the privately owned reserves of Mashpi and Amagusa. Additional populations of C. fluidifolia are known along the primary road that connects the two reserves. Based on the available information and according to the IUCN Red List criteria ( IUCN 2012; IUCN Standards and Petitions Committee 2019) C. fluidifolia is preliminarily assessed as Critically Endangered (CR) based on an EOO <100 km2 (B1), limited geographic range (criteria B1 + 2a, b), and restricted population of fewer than 50 individuals (D).

Comments.

Columnea fluidifolia differs from most Columnea by the presence of pendent elongate shoots and paired leaves that are both anisophyllous (Fig. 2A ) and isophyllous (Fig. 2B ). In addition, the shallowly bilabiate to tubular corolla and relatively large leaves (> 4 cm long) are not typical for other Columnea with pendent elongate shoots. In contrast, most Columnea with pendent elongate shoots have corollas that are deeply bilabiate and small leaves (<4 cm long). Columnea fluidifolia is similar to C. ceticeps . The calyx lobes and corolla are orange in C. fluidifolia (Fig. 2 ). In contrast, the calyx lobes are green, and the corolla is bright orange in C. ceticeps (Fig. 4 ). The corolla tube in C. fluidifolia is nearly tubular without the presence of a bilabiate limb (Figs 2 , 3 ). In contrast, the corolla tube in C. ceticeps is deeply bilabiate (Fig. 4 ).

Ecuador. Pichincha: Distrito Metropolitano de Quito, Bosque protector Mashpi, Trasecto Mashpi Laguna 0.169750°N, 78.872120°W, 1150 m, 27 Jun 2017, F. Tobar et al. 2908 (QCA); Bosque protector Mashpi, Trasecto Mashpi Laguna 0.169750°N, 78.872120°W, 1150 m, 21 Sep 2018, F. Tobar et al. 3267 (QCA).

Figures

Figure 1. Distribution of Columnea ceticeps (squares), C. fluidifolia (triangles), and C. pendens (circles). Note that range of C. ceticeps extends into the Colombian departments of Choco, Antioquia and Risaralda (not featured here) (map provided by Marco F. Monteros).

Figure 2. Columnea fluidifolia J. L. Clark & F. Tobar A lateral view of mature flower B anisophyllous leaf pairs C isophyllous leaf pairs (base & apex) and anisophyllous leaf pairs (middle) D immature berry E mature berry (A, B, D from J. L. Clark 16286 C, E from A. J. Perez & F. Tobar sn). Photos A, B, D by J. L. Clark & C, E by F. Tobar.

Figure 3. Columnea fluidifolia J. L. Clark & F. Tobar A pendent shoot B lateral view of flower C bilobed dorsal nectary gland and ovary D mature calyx with style E stomatomorphic stigma F corolla opened featuring mature anthers G mature corolla. Illustration by M. J. Gavilanes.

Figure 4. Columnea ceticeps J. L. Clark & J. F. Sm. A mature flower B pendent shoot C deeply bilabiate corolla D calyx lobes (A-D from J. L. Clark 12950 D photos by J. L. Clark.