Pleurothallis tenuisepala Mark Wilson 2019 SUBGENUS Pleurothallis SECTION Pleurothallis SUBSECTION Acroniae SERIES Acroniae Luer 1988

Comparrison between P luctosa and P tenuisepala

LCDP Photos by Mark Wilson

Common Name The Thin Sepal Pleurothallis

Flower Size 2.4” [6 cm] long

Found in Choco, Risaralda and Cauca departments of Colombia at elevations around 2200 meters as a miniature sized, cold growing caespitose epiphyte with suberect, slender, terete ramicauls enveloped basally by a papyraceous sheath and carrying a single, apical, suberect to spreading, narrowly ovate-lanceolate, acute, minutely mucronate, cuneate below into the sessile base leaf that blooms in the spring and again in the fall on an arching, arising through a reclining spathe, peduncle 1.08” [2.7 cm] long, distichous, 3.2” [8 cm] long overall, 4 to 6 flowered inflorescence with a tubular, membraneous, much shorter than the pedicel floral bract and carrying long flowers.

”Although previously misidentified, Pleurothallis tenuisepala from Cauca, Colombia is very easily distinguished from the Costa Rican species Pleurothallis luctuosa based on floral morphology. How then could such a misidentification occur? Vegetatively the species are indeed very similar and both produce lax racemes of pale purplish flowers. It is likely that Luer had not seen living material of P. luctuosa in Costa Rica when, presumably in comparison to the drawings by Reichenbach and Endrés, or to the type material, he concluded that the Ecuadorian species was P. luctuosa. A drawing under that name was included in Icones Plantarum Tropicarum series I (plate 242 - Dodson et al. 1980). Then, in 1991, upon examination of the material from PNN Gorgona collected by Killip and Garcia, presumably due to the similarity with the Ecuadorian material, Luer identified this Colombian specimen to also be P. luctuosa (Fig. 9). Subsequently, the use of the P. luctuosa drawing from Icones Plantarum Tropicarum in the monograph on subsection Acroniae (Luer 1998) cemented the belief that the species in Ecuador and Colombia were P. luctuosa, that is until the identification was questioned by Pupulin et al. (2010). Future studies in the Acroniae will examine the species from Santo Domingo, Pichincha, Ecuador, to determine whether it is distinct from Pleurothallis tenuisepala and will investigate the phylogenetic relationships between P. tenuisepala, Pleurothallis sp. “Santa Domingo” and the other members of the Central and South American subsection Acroniae.” Wilson etal 2019

Synonyms

References W3 Tropicos, Kew Monocot list , IPNI ; Icones Planetarum Tropicarum plate 242 Dodson 1980 drawing not = P tenuisepala?; Icones Pleurothallidinarum Vol XVII Systematics of Pleurothallis Section Abortivae, Truncatae, Subsection Acroniae, Subgenera Dracontia and Uncifera Luer 1998 drawing fide; Native Colombian Orchids Vol 6 COS 1998 photo fide; *Lankesteriana 19(2). 82 2019 photo fide

----------------------------------------------------------------------------------------------------------