Maguire, Bassett & Wurdack, John J. 1958. The botany of the Guayana Highland--Part III. Mem. New York Bot. Gard. 10: 1-156.
Xyridaceae
Species Description - Caulescent perennial herb; herbage not glaucous; stems 0.5-2.0 m tall; leaves numerous, rather laxly conferted but not rosulate, linear-lanceolate, obviously or not at all brown-margined, pungently acute, 15-30 cm long1, 1-5 cm broad; peduncles more often several (solitary in the type) : sterile bracts in 2 whorls of 3's; inflorescence and flowers otherwise similar to those of O. sceptrum.
Abolboda ptaritepviann Steyermark, Fieldiana Bot. 28: 104. 1951.
Type: in dense thickets and Bonnetia roraimae forest southwest facing shoulder, Ptari-tepui, Edo. Bolivar, Venezuela, Nov 2, 1944, Steyermark 59760.
Orectanthe ptaritepuiana is distinguished from O. sceptrum largely by means of vegetative differences, and to some extent on geographical grounds. The first is characterized by well developed leafy stems and the prevalence of 3 or more peduncles, as contrasted to O. sceptrum which has very short stems and densely rosulate leaves. Although variable in size and trivial detail, there seems to be no way conclusively to separate the two species by floral distinction. They both occupy the geographical range in eastern Guayana, but only O. sceptrum is to be found in western Venezuelan Guayana. Both species inhabit upper cumbre habitats; only 0. sceptrum occurs also at low altitude (1000 m) on the Gran Sabana.
Venezuela South America|