Oncidium exauriculatum (Hamer & Garay) R. Jiménez 1992 SECTION Rostrata

Comparison shot of O exauriculatum and O cheirophorum TYPE Drawing/Photos R Jimenez © and The Herbario AMO Website

Fragrance Part Shade Warm Cool EARLIERFall EARLYWinter

Common Name The Without Ears Oncidium [refers to the lack of column wings]

Flower Size .32 to 52" [8 to 13 mm]

Found in Chiapas state of Mexico, Guatemala, El Salvador, Nicaragua and Costa Rica in montane rainforest at elevations of 700 to 1400 meters as a mniature to small sized, warm to cool growing epiphyte with clustered, ovate to sub-rhombic, strongly compressed, smooth, rugose with age, green often with purple spots which can be dense to be almost totally purple pseudobulbs carrying 1 to rarely 2, apical, sub-coriaceous, linear-elliptic to lanceolate, erect-arcuate, dorsally carinate, acute, basally conduplicate leaves that blooms in the earlier fall through early winter on 1 to 3, basal on a mature pseudobulb, erect to slightly arcuate, peduncle laterally compressed, from 2.4 to 6" [6 to 15 cm] long, paniculate, 2 to 4 branched, each branch .6 to 1.8" [1.5 to 4.5 cm] long, sometimes with secondary branches, 4.8 to 10.4" [12 to 26 cm] long, laxly, successively 7 to 28 flowered inflorescence with triangular, basally tubular floral bracts and carrying lightly scented flowers

Differs from the often cited as synomonous Onc cheirophorum by the lack of the aruricles of the column, geograpically, as it is not found in Panama and Colombia and in the autopollination of the flowers of Onc exauriculatum. O auriculatum also has mostly erect, paniculate, more spaced, less flowered inflorescence as well as successively opening flowers with a narrow stipe. Onc cheirophorum has large prominent auricles to the column, is found in Costa Rica, Panama and Colombia, is rarely cleisostogamus, arcuate-pendent inflroescence with many, simultaneously opening, clustered, flowers which have a wider stipe

CAUTION Kew keeps this one as a synonym and variety of Oncidium cheirophorum but I, like R Jimenez, feel that it is substantially different and so i have kept its species status.

Synonyms Oncidium cheirophorum var. exauriculatum Hamer & Garay 1974

References W3 Tropicos, Kew Monocot list , IPNI ; *Orquídea (Méx.) 12(2): 269-276. R Jimenez 1992. photo/drawing fide

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