Aa leucantha (Rchb.f.) Schltr. 1920
TYPE Drawing as Aa nigriscens by Schlechter and The Swiss Orchid Foundation at the Jany Renz Herbaria Website
LATE 
EARLY
Common Name The White Flowered Aa
Flower Size Minute
Found in Santander, Cundinamarca and Nariño departments of Colombia and Imbabura province of Ecuador at elevations of 3000 to 4200 meters as a medium sized, cold growing terrestrial with when present, rosulate, ovate-lanceolate, acute, fleshy, shortly petiolate base leaves that blooms in the late spring and summer on an erect, completely enveloped by imbricating, diaphanous sheaths terminated by a short to 2.4" [6 cm] long, cylindrical, densely many flowered inflorescence with lanceolate, ovate-lanceolate to oblong-lanceolate, acuminate, diaphanous, coarse erose margins, almost 4 times longer than the ovary floral bracts and carrying small, more or less fleshy-coriaceous flowers.
"Distinguished by the elongate floral bracts recurved at the midpoint and entire sepal margins. The most similar species is Aa maderoi which also has elongated floral bracts, but the sepals are irregularily denticulate to erose along the margins. Additionally the floral bracts of A Leucantha are acute to acuminate versus long attenuate in A maderoi. A leucanthat has very short, scale like and subsessile leaves." Szlachetko & Kolanowska 2019
Synonyms Aa nigrescens Schltr. 1920; *Altensteinia leucantha Rchb.f. 1886; Altensteinia nigrescens (Schltr.) Løjtnant 1977
References W3 Tropicos, Kew Monocot list , IPNI ;
Flora 69: 548 Rchb.f 1886 as Altensteinia leucantha
* Repert. Spec. Nov. Regni Veg. Beih. 7: 213 Schlechter 1920
Repert. Spec. Nov. Regni Veg. Beih. 7: 49 Schlechter 1920 as Aa nigrescens
Venezuelan Orchids Illustrated Vol 5 Dunsterville & Garay 1966 as Altenstenis leucantha not = Aa hartwegii;
Bot. Not. 130: 164 Løjtnant 1977 as Altensteinia nigrescens
Flora of Ecuador 9(225: 1): 168 Garay 1978 drawing fide;
Flora Of Ecuador # 76 225[2] Dodson & Luer 2005;
Orchids, A Colombian Treasure Vol 1 Ortiz & Uribe 2014
Materials to the Orchid Flora of Colombia Vol 2: 22 Szlachetko & Kolanowska 2019 drawing not = Aa hartwegii
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