Monographs Details: Oreobolus obtusangulus subsp. rovaginatus (Kük.) T.Koyama
Authority: Maguire, Bassett. 1969. The botany of the Guayana Highland-part VIII. Mem. New York Bot. Gard. 18: 1-290.
Family:Cyperaceae
Description:Distribution and Ecology - Additional distribution. BRAZIL. Amazonas: Rio Negro, Serra da Neblina, openslopes to base of cliffs, alt 8500-9000 ft, B. Maguire et al 60492 (NY); Rio Negro,summit of Serra da Nebhna, alt 8000-8500 ft, Maguire et al 60540 (NY).

Discussion:

Oreobolus obtusangulus Gaudichaud var rubrovaginatus Kiikenthal, Repert. Sp. Nov. 48: 69. 1940. Type. COLOMBIA. El Boqueron near Bogota, 3200-3700 m, C. Troll 3790 (B).

The discovery of Oreobolus obtusangulus from the Serra da Neblina is of considerable phytogeographical interest. In South America the genus Oreobolus has hitherto been strictly confined to the Andean region from Chile through Andean Ecuador and Colombia northward to the State of Tachira of Andean Venezuela. The two collections cited mark the first record of Oreobolus in the Guayana Highland. Although the specimens from Neblina lack flowers they precisely agree with Oreobolus obtusangulus subsp rubrovaginatus of Ecuador and Colombia in every vegetative aspect. Subspecies rubrovaginatus differs from subsp obtusangulus in the reddish or orange-brown coloration of leaf sheaths and by the leaf blades that are shiny and only 3-veined on the obtuse back. In the latter subspecies the leaf sheaths are grayish, and the leaf blades are dull with prominently ridged three costas on the abaxial side.

Distribution:Brazil South America|