Monographs Details: Xyris atriceps subsp. chimantensis Maguire & L.B.Sm.
Authority: Maguire, Bassett & Wurdack, John J. 1964. The botany of the Guayana Highland--Part V. Mem. New York Bot. Gard. 10: 1-278.
Family:Xyridaceae
Description:Latin Diagnosis - Herbae ex comparatione parvae; foliis 12 cm hand superantibus; scapo plerumque 15-20 cm longo; spica ca. 6 mm longa; bracteis lanceolatis, plus minusve carinatis, valde rugosis, marginibus profunde pectinato-incisis.

Distribution and Ecology - Distribution. Only the type collection known; quite distinctive in habit, of spikes and form of spicular bracts.

Discussion:Type. Sheaths blackish-purple at base, culms purple-black, involucre blackish, petals deep yellow, 5 m m long, locally frequent, Rio Tirica, alt. 1925 m, 5 Feb 1955, Chimanta Massif, Bolivar, Venezuela, Julian A. Steyermark & John J. Wurdack 485 (holotype N Y , isotype U S ) .