Telipogon diabolicus (Orchidaceae, Oncidiinae), a new species from southern Colombia

Abstract A new species of the orchid genus Telipogon, Telipogon diabolicus, is described and illustrated. The information about its habitat is provided. The novelty resembles Telipogon tabanensis and Telipogon guacamayensis and it is characterized by the translucent flowers, the glabrous, distinctly clawed petals, the transversely elliptic lip, and the gynostemium ornamented with long setose hairs on both sides and shorter hairs at the apex.


Introduction
Th e Neotropical genus Telipogon was established about 200 years ago by Karl Kunth (1816) who recognized only two species within newly published taxon: T. angustifolius and T. latifolius. Th e former orchid was earlier recognized as Tradescantia nervosa and transferred to Telipogon by Druce (1917). During the 19th century, over 40 new species within the genus were described by Reichenbach (e.g. Reichenbach 1854, 1877. Pfi tzer (1887) included Telipogon in Notylieae tribe while Schlechter (1915) proposed to unite Trichoceros, Telipogon and Stellilabium in a separated subtribe named Telipo-goninae. Dressler and Dodson (1960) classifi ed those genera in Ornithocephalus alliance, but Schlechter's proposal was accepted by subsequent morphological taxonomists (e.g. Burns-Balogh and Funk 1986, Dressler 1993, Szlachetko 1995. Th e results of molecular studies provoked Chase et al. (2003Chase et al. ( , 2015 to lump all genera mentioned before together with over 50 other taxa in Oncidiinae. Until 2005 about 190 specifi c epithets were applied to Telipogon. Williams et al. (2005) revealed that, according to the results of phylogenetic studies, Stellilabium is embedded within Telipogon and 36 species of the former genus were transferred by the authors to Telipogon. Th e novelties within the genus have been frequently published in the last years (e.g. Dressler 2007, Nauray Huari and Galán de Mera 2008, Baquero and Fortunato 2012, Jiménez Pérez 2012, Collantes and Martel 2015 and so far a total of about 250 specifi c epithets are listed under Telipogon according to Th e International Plant Names Index (2016).

Description of the new species
Etymology. Th e specifi c name refers to the distinctive gynostemium which resembles devil's head.
Distribution and ecology. So far this species is known exclusively from southern Colombia, on the border between departments Putumayo and Nariño. It was found  Conservation status. IUCN Red List category: Critically Endangered, [CR B2ab(iii)]. Th is species is only known from the type specimens, which represent one location in highly vulnerable habitat near the main road Pasto-Mocoa. It is expected that the current reconstruction of this road will have negative impact on the habitat of T. diabolicus.
Discussion. Th e new species can be misidentifi ed with its Colombian congener T. tabanensis Dodson & R. Escobar (1993) and Ecuadorian T. guacamayensis Dodson & R. Escobar (in Dodson 1989a), but both those orchids are characterized by yellow fl owers with dark (wine-red to maroon) gynostemium and callus (vs fl owers translucent in T. diabolicus). Flowers of both T. tabanensis and T. diabolicus are resupinate (non-resupinate in T. guacamayensis), but those of T. tabanensis are much largersepals are about 17 mm long (vs 9-10 mm in T. diabolicus), petals reach 20 mm in length (vs 12 mm). Petals of the former are densely spinose-hirsute at the base while in the new species and in T. guacamayensis (Fig. 3) they are glabrous. In both T. tabanensis (Fig. 4) and T. guacamayensis the lip is 17-veined (vs 15-veined in T. diabolicus) and it is subtrullate (T. guacamayensis) or elliptic (T. tabanensis). All three species are  Dodson and Escobar (1993). Scale bars: A-F = 10 mm, G = 5 mm. characterized by presence of prominent, more or less cordate basal lip callus which is about 6 mm long in T. tabanensis and T. guacamayensis (up to 4 mm in T. diabolicus). Only in T. diabolicus the basal lip margin is covered with short spines. Th e additional diff erence between T. tabanensis and the new species is found in the gynostemium ornamentation. In the former orchid it is covered with equally long setose hairs while in T. diabolicus (and T. guacamayensis) the lateral bundles of hairs are elongated, longer than the dorsal bundle covering the anther.
Th e most distinguishing character of the new species are prominently clawed petals. At the best of our knowledge, this character is not found in any other Colombian species of the genus. Interestingly, at least 3 species from Peru share this feature, i.e. T. intis Braas (Fig. 5), T. lueri Dodson & Bennett (Fig. 6) and T. mendiolae Dodson & Bennett (Fig. 7). In the fi rst of the Peruvian species aforementioned the obtuse lip has 17 nerves, petals are acute and gynostemium is sparsely setose on clinandrium. T. mendiolae can be characterized by transversely elliptic, obtuse lip with 17 nerves, and transversely elliptic, shortly apiculate petals. Flowers of this species are about twice larger than those of T. diabolicus. T. lueri diff ers from our new species by having twice larger fl owers, densely setose gynostemium and petals with 11 nerves.
Telipogon diabolicus somewhat resembles also Ecuadorian T. ecuadorensis Schltr. (Fig. 9) and T. bruchmuelleri Rchb.f. (Fig. 8) known from Ecuador and Venezuela. In all aforementioned species the lip is similar in form, i.e. more or less transversely elliptic with ovate-cordate basal callus. Unlike in T. diabolicus the gynostemium of T. bruchmuelleri and T. ecuadorensis is densely covered by setose hairs (vs setose hairs found only on clinandrium), and petals are sessile (vs clawed).   Dodson and Bennett (in Dodson 1989b