Monographs Details: Conceveiba ptariana (Steyerm.) Jabl.
Authority: Maguire, Bassett. 1967. The botany of the Guayana Highland--Part VII. Mem. New York Bot. Gard. 17: 1-439.
Family:Euphorbiaceae
Description:Distribution and Ecology - Known only from high altitudes of Bolivar. VENEZUELA. Bolivar: Uriman region, below the second mesa of Aprada Tepui, alt 1350 m, Aug 1953, Bernardi 976 (sterile NY); Chimanta Massif, forested slopes adjacent to Quebrada, vicinity of camp 3, northwest part of Abacapa-tepui, alt 1300 m, 20 Apr 1953. Steyermark 75185 (sterile NY); Chimanta Massif, vicinity of Bluff Camp, at base of west-facing sandstone bluffs of Chimanta-tepui (Torono-tepui), alt 1700 m, 2-4 Jun 1953, Steyermark 75619 (sterile NY); wet forest on summit of low pass over summit of Sierra Lema, headwaters of Rio Chicanan, 80 km SE of El Dorado, lat 6°5'N, long 62° W, alt 700m, 22 Aug 1961, Steyermark 89406 (fr. NY); Cerro Venamo, alt 1220-1275 m, 6-7 Jan 1964, Steyermark & Dunsterville 92712 (sterile NY); wet forest in the vicinity of km 119 S of El Dorado, alt 1030 m, 12 Jan 1964, Steyermark & Dunsternille 92990 (female, male NY)

Discussion:

Conceveibastrum ptaianum Steyermark, Fieldiana Bot. 28: 308. 1952.

Type. Ptari-tepui, southeast-facing slopes, altitude 1585-1600 m, 10-11 Nov 1944, State of Bolivar, Venezuela, Julian A. Steyermark 60021 (isotype NY) The type is a sterile specimen.

This is a highly interesting, well-defined, and the best-collected species of Conceveiba. A typical endemic of high altitude, it differs from all other known Conceveiba by the lack of differentiation of the androeceum into an inner sterile portion and a fertile outer circle. However the fruit, and stigmata and the vegetative characters are all very typical of Conceveiba. It is a matter of personal judgment rather than a precise conclusion whether C. ptariana should be referred to a distinct genus. Early confusion caused by inadequate collection of male and female individuals led to an unnecessary splitting of the genus into Conceveiba, Conceveibastrum and Veconcibea. Should we follow this old tradition, then C. ptariana would certainly deserve to be established as a new genus.

Distribution:Venezuela South America|