MARISOL AMAYA-MÁRQUEZ
Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Apartado 7495, Bogotá D.C., Colombia. mamayam@unal.edu.co
ABSTRACT
A new species of Columnea (Gesneriaceae) recently found in a premontane forest in the National Natural Park Las Orquídeas (Cordillera Occidental), in the Department of Antioquia in Colombia , is described and illustrated.
Key words. Columnea, Gesneriaceae, Corolla appendages, Ornithophily, Antioquia, Flora of Colombia.
RESUMEN
Una nueva especie de Columnea (Gesneriaceae) hallada en un bosque premontano en el Parque Nacional Natural Las Orquídeas (Cordillera Occidental), en el departamento de Antioquia, en Colombia es descrita e ilustrada.
Palabras clave. Columnea, Gesneriaceae, Apéndices de la corola, Ornitofilia, Antioquia, Flora de Colombia.
Recibido: 11/10/2013
Aceptado: 18/11/2014
INTRODUCTION
Columnea is a neotropical genus containing over 205 species (Möller & Clark 2013) that is presumably exclusively pollinated by hummingbird species (Morley 1966, 1971; 1973; Wiehler 1983). As a consequence mutual co-adaptations between these two groups of organisms have emerged (e.g. Amaya-Márquez 1996). Traits of Columnea species associated with ornithophilous pollination are: 1) larger leaf with extrafloral marks or red indument that functions as a secondary and lasting attractant for the birds (Jones & Rich 1972; Kastinger & Weber 2000; G. Stiles pers. com.); 2) diurnal nectar production in concentrations between 12-25 % (Amaya-Márquez 1996); 3) tubular corolla that is basally spurred, often sigmoid, the tube slightly inflated, straight or dorsally curved, less often funnelform, and the limb bilabiate or subactinomorphic, 1 to 7 cm long (values that match most of the range in hummingbirds bill length); 4) corolla tube color orange, red, or yellow, sometimes with contrasting nectar guides on the limb; 5) calyx and bracts may be of the same color as the corolla, in which case the reproductive structure, as a whole, contrasts with the foliage; and 6) in other cases the calyx and the bracts are colored differently than the corolla, and the final result in both cases is an increase in the visual impact. During recent years, along with discovering new species, new floral traits have been described. In particular, investigations on corolla appendages have broadened our knowledge on the architecture of the flower of Columnea (Amaya-Márquez et al. 2004; Clark & Clavijo 2012). In this paper a new species of Columnea recently found in a premontane forest in the National Natural Park Las Orquídeas ( Cordillera Occidental) is described and illustrated. This species has a corolla limb adorned with four white, geniculate external appendages.
Columnea figueroae M. Amaya sp. nov.
Fig. 1 & Fig. 2.
TYPE: Colombia: Antioquia, municipio Urrao, corregimiento La Encarnación, vereda Calles, National Natural Park Las Orquídeas, road between Calles and La Encarnación after the confluence of Río Polo and Río Calle, before Río San Pedro, sitio La Quiebra. 16001850 m, Jan 31 Feb 2, 2011, Pedraza-Peñalosa, P. et al. 2096 (holotype: COL).
Columnea figueroae differs from C. paraguensis by having a red corolla with longitudinal white stripes (vs. homogenously yellow orange); corolla limb bent downward (vs. corolla limb erect); four white corolla appendages of different size, geniculate (vs. four yellow corolla appendages of same size, not geniculate); nectary one dorsal gland (vs. two dorsal glands); and 12-13 veins on the larger leaf in a pair (vs. 9-10 veins).
Suffrutescent vine, 1.5 m tall. Stem subterete, 0.5 cm in diam., epidermis green, indument reddish pilose (of 8-12-celled trichomes); internodes 1- 2 cm long. Leaves opposite, strongly anisophyllous in a pair, chartaceous; larger leaf in a pair with petioles 0.6- 1 cm long, densely reddish-pilose (7-9-celled trichomes), blade asymmetrical, narrowly oblanceolate to falcate, 19.0-23.5 X 3.9- 5.8 cm, base oblique, shorter side acute, larger side rounded, apex acuminate, margin dentate, adaxially green, reddish-pilose (6-12-celled trichomes), abaxially green, reddish-pilose (6-12-celled trichomes) more dense on the veins, 12-13 veins on the larger side of the blade; smaller leaf in a pair sessile, lanceolate, 1.5 X 0.3 cm, base oblique, apex attenuate, adaxially reddish-pilose (6-12-celled trichomes), abaxially reddish-pilose (6-12-celled trichomes). Inflorescence fasciculate, up to 5 flowers and 8 bracts per axil; bracts lanceolate (basally cuneate), unequal, ranging from 1.1 X 0.1 cm to 3.4 X 0.8 cm, adaxially glabrous, abaxially reddish-pilose (5-8-celled trichomes), margin denticulate. Flower shortly pedicellate, pedicel 0.3- 0.4 mm with white glands near the calyx. Calyx apically red, white-pale green at the base; lobes connate basally by 0.1 cm of their length, subequal, lanceolate, 1.8-2.5 X 0.2- 0.3 cm, adaxially glabrescent, abaxially reddish-pilose (7-10-celled trichomes), margin dentate with 2-3 subulate teeth per side. Corolla red with longitudinal white lines on the exterior surface of the tube, corolla tube slightly curved dorsally, 2.8- 3.3 cm long, 0.7 cm wide at the middle, constricted at the base 0.4 cm, base dorsally gibbous, gibbosity 0.3 X 0.5 cm, limb zygomorphic, 0.5 cm wide, lobes bent inward, unequal, the two dorsal lobes obtuse, 3-5 X 3 mm, the three ventral lobes acute, 1.3-1.5 X 1.3- 2.3 mm, margin erose; pilose, except on longitudinal stripes that are white and glabrous, inside glabrescent, glandular in the throat; 4 white external reflexed and geniculate appendages outside the lobes, two of the appendages 7- 9 mm long, 1 mm wide, pilose (2-5-celled trichomes), two lateral appendages 4 mm long, 1 mm wide. Androecium of 4 stamens, filaments glabrous, basally connate by 0.3 cm of their length forming a staminal blade; anthers subquadrate 2.1 X 2.0 mm. Gynoecium with ovary conical, 4.0 X 2.5 mm, apically pilose (7-11-celled trichomes), style 2 cm long, glandular (2-celled trichomes) along its length; stigma bilobed. Nectary of one dorsal tridentate gland, 2 X 2 mm. Fruit an ovoid berry, 1.3 X 1.0 cm. Seeds honey colored, obliquely striated, 2.0 X 0.5 mm.
Etymology. The species is named for my husband, Jorge Luis Figueroa, to whom this species is dedicated as an expression of love and admiration for him, and also in acknowledgment of his great value as a person who is kind, compassionate, responsible, very intelligent, and who seeks to help those around him as much as is possible. He has given me invaluable support through the entirety of my career.
Phenology: Flowers and fruits have been recorded on the holotype specimen collected between January and February of 2011.
Distribution: A rare species collected in a premontane wet forest in the Cordillera Occidental of Colombia in the department of Antioquia at an elevation between1600- 1850 m. The species can be considered vulnerable because it is known from only one locality in a relic of a premontane forest surrounded by disturbed vegetation. The relic is probably in good shape because it is found on steep terrain of difficult access. The species has not been collected before despite the fact that several botanists have visited the region over many years. According to the IUCN these two criteria will place the species in the category of endangered, however in this paper the species is considered in the category of vulnerable due to two factors: (1) around the area where the species was collected the natural habitat was disturbed, but the locality is found within the limits of a National Natural Park, therefore there is hope that the deforestation does not advance; (2) due to the fact that the vegetative shoot of the species looks similar to the specimens of the complex of species C.sanguinea/C.purpurata, it might happen that the species is not rare, but that it has been collected before in a sterile phase, and the specimens might be misplaced in the herbaria. If the last were the case then the population of C. figueroa might be in good shape in other well conserved places of the National Natural Park Las Orquídeas. Thus, further investigation on the status of this species is required.
Representative specimens: COLOMBIA : The species is known only from the holotype.
Distinctive characters
Columnea figueroae has a dorsiventral shoot, the leaves are chartaceous, adaxially green and abaxially pale green with a reddish indument throughout the blade. The red bracts from different leaf axils overlap forming a structure that contrast with the rest of the plant. The corolla is red with white longitudinal stripes, tubular with the limb bent downward, and it has 4 white geniculate appendages (Figure 2).
Classification
The four external appendages in the corolla of C. figueroae are similar to those found in some species of section Ortholoma Benth. However, C. figueroae and C. paraguensis a recently described species (Amaya-Márquez & Smith 2012) are unique within the genus Columnea by having a mix of traits typical of section Ortholoma (i.e., external corolla appendages) and of section Collandra (Lem.) Benth. (i.e., vegetative dorsiventral shoots with short internodes). In the description of C. paraguensis the species was considered unique within the genus due to this combination of traits. In fact, a sterile specimen of C. paraguensis can be confused with a specimen of C. fuscihirta (sect. Collandra). The same situation occurs with C. figueroae where the vegetative shoots without flowers can be confused with specimens of the Columnea sanguinea/Columnea purpurata complex. However, C. figueroae when seen with flowers is a unique species, distinct from any other species of Columnea known so far; the four external appendages, homogenously white, long, and geniculate give the corolla an impressive visual impact (Figure 2).
There are other species of section Collandra that also have appendages in the corolla, for example Columnea coronata. In C. coronata there are five external appendages, laminar, and set in whorls that resemble the corolla limb, while the real corolla limb is in an inner position resembling a corona (Figure 3). In fact, this corolla limb was interpreted as a corona by Amaya-Márquez et al. (2004), based on the continuity of the petal veins in the appendages. However, additional morphological observations of live C. coronata flowers have shown that the external appendages are located under the corolla limb, at the sinuses of the corolla (Figures 3A, 3B). The position of these appendages is equivalent to those found in some species of section Ortholoma, as is the case for Columnea minor. Additionally, there are other species in section Collandra for which the corolla lobes are long, free, and filiform (C. nematoloba, C. filifera, and C. incredibilis). In two of these species, C. filifera and C. incredibilis the corolla appendages are located in front of each corolla lobe (Figure 4).
Here C. figueroae is not assigned to any section of Columnea. It likely belongs to clade C of the phylogeny obtained by Smith et al. (2013) based on the shared morphological traits: corolla shape, stripes along the corolla, leaves oblanceolate, slightly falcate with a dorsiventral arrangement similar to those of section Collandra, and the stem and the leaves often with a tawny hispid indumenta. However, the species in Clade C such as C. brenneri, have five external appendages, while C. figueroae has four. Given the different position, number, shape and texture of the corolla appendages found within the species of Columnea, a detailed study about these structures is needed.
As far as we know, Columnea is a genus strictly pollinated by hummingbirds (Morley 1971; Jones & Rich 1972; Wiehler 1983; Amaya-Márquez 1996; Kastinger & Weber 2000). However, floral phenotypes with external appendages on the corolla have not been acknowledged within the syndrome of ornithophily (e.g., Proctor et al. 1996).
ACKNOWLEDGMENTS
The author thanks the National University of Colombia for the opportunity to do research, Juan Carlos Pinzón for the drawings, Jim Smith for his discussion on the taxonomical placement of the new species, Julio Betancur for his collaboration and for allowing the use of his picture shown in Fig. 2 in this publication, Oscar Humberto Marín Gómez collected flowers of C. coronata to conduct the morphological study of the corolla and he allows the use of his pictures shown in Figs. 3C, 3D, 4A & 4B; and finally to Larry Skog, John L. Clark, Jim F. Smith, and three anonymous reviewer for their help in revising the manuscript, and their valuable observations which helped to greatly improve the manuscript. The NSF funded the project Flora of Las Orquídeas National Park to Paola Pedraza (DEB 1020623) provided funding to do the collections.
LITERATURE CITED
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