Pleurothallis bicornis Lindl. 1859 SUBGENUS Pleurothallis SECTION Pleurothallis SUBSECTION Macrophyllae-Racemosae [Lindl] Luer 1986

Photo courtesy of Lourens Grobler

Another Flower

Photo by NELOCACTUS Website

Drawing of Comparison of lips

Drawings by C A Luer

Full shade Cool Cold

Common Name The Two Horned Pleurothallis [refers to the petals]

Flower Size .2" [5 mm]

Found in Venezuela, Colombia, Ecuador and Peru in moist forests at elevations of 1250 to 3000 meters as a medium to large sized, cool to cold growing epiphyte with stout erect ramicauls enveloped basally by 2 to 3, close tubular sheaths and another below the middle and carrying a single, apical, erect, coriaceous, elliptical, acute, cuneate below into the sessile base leaf that blooms in the fall on 1 to 7, arching, lax, several flowered, 4 to 7.2" [10 to 18 cm] long, racemose inflorescence arising from a spathe and has infundibular floral bracts.

" Pleurothallis caucensis can be distinguished from P. bicornis by the petals, which in P. caucensis are free, projected laterally and downward and in P. bicornis are adpressed and project forwards; by the lip which is completely fimbriated in P. caucensis and only fimbriated on the margin of the central lobe in P. bicornis; and by the lateral lobes of the lip which are flattened and surpass the column in P. caucensis and which are auriculate, not surpassing the column in P. bicornis. Pleurothallis caucensis differs from P. subreniformis in the length of the raceme, sepals and petals, which are longer in P. caucensis than in P. subreniformis; and in the lip shape, which is suborbicular in P. caucensis and hippocrepiform with an acute apex on the midlobe in P. subreniformis. Pleurothallis caucensis differs from P. torrana in the length of the ramicauls, raceme, sepals and petals, all of which are longer in P. caucensis than in P. torrana in the lip shape which is suborbicular in P. caucensis and rhombiform in P. torrana; and in the lip callus, which consists of a pair of lunate calli in P. caucensis and a single transverse callus in P. torrana." Wilson etal 2017

Synonyms Humboldtia bicornis (Lindl.) Kuntze 1891

References W3 Tropicos, Kew Monocot list , IPNI ; Orchids of Venezuela An Illustrated Field Guide Vol 3 Dunsterville & Garay 1979 as P secunda in part drawing hmm; Icones Pleurothallidinarum III. Systematics of Pleurothallis Luer 1986; Native Colombian Orchids Vol 6 Img #1215 COS 1998 photo fide; Icones Pleurothallidinarum XVIII Luer 1999 drawing fide; Orchids of Venezuela [An illustrated field guide] Vol. 3 Ramiro and Carnevali 2000 drawing hmm; Native Orchids of Ecuador Vol 4 Dodson 2003 drawing fide; Orquideas Nativas del Tachira Cesar Fernandez 2003 photo not; Orchid Species of Peru Zelenko & Bermudez 2009 photo fide; LANKESTERIANA 17(2) Wilson 2017 drawing/photo fide

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