Monographs Details: Psychotria iodotricha subsp. atricapilla (Bremek.) Steyerm.
Authority: Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.

Petagomoa atricapilla Brem., Rec. Trav. Bot. NĂ©erl. 31: 296. 1934.

This is a variation of P. iodotricha having the upper surface of the leaf blades glabrous or nearly so. Two to four inner bracts free to the base are present within the outer involucre or may be absent. The outer bract of the involucre is united at the base and varies from one nearly uniform split into four bilobate or trilobate lobes, to a more unequally lobate type having two to four main lobes often trilobate with the lateral lobes shorter and narrower. The lateral nerves on the iso type collection vary in number from 7-8 each side on the smaller leaves to 12-13 on the larger leaves, although Bremekamp states that only 12-13 are present on each side. The lower surface of the leaf blades is stated in the original description to be sparsely hirsute, but an examination of an isotype specimen at NY shows a moderately to nearly densely hirsute lower surface, as do other collections, such as Irwin, Prance, Soderstrom & Holmgren 54733.