Monographs Details: Cassia sect. Absus
Authors:Howard S. Irwin, David J. Rogers
Authority: Irwin, Howard S. & Barneby, Rupert C. 1978. Monographic studies in Cassia (Leguminosae, Caesalpinioideae). III. Sections Absus and Grimaldia. Mem. New York Bot. Gard. 30: 1-300.
Discussion:

1. CASSIA sectio ABSUS DeCandolle ex Colladon emend. Irwin & Barneby

Cassia sect. Absus DeCandolle ex Colladon, Hist. Casses 82, 116, pro parte, exclus. C. absus. 1816. — Sp. typica, the decandrous species that alone agrees with the sectional diagnosis: C. hispida Colladon = C. tetraphylla Martyn. — Cassia absus L., chosen as lectotypus by Symon (1966, p. 77) must be rejected, despite the eponymous epithet. — C. sect. Absus sensu Bentham, 1870, 130—155 (exclus. C. absus); 1871, pp. 558—567 (exclus. C. absus).

Cassia sect. Lasiorhegma Vogel, Syn. Gen. Cass. 49, quoad divisionem A, exclus. C. absus. 1837, nom. iIlegit.

Grimaldia sensu Britton & Rose, 1930, p. 299, exclus. typ.; Britton & Killip, 1936, p. 187, exclus typ.; non Grimaldia Schrank, sens. str., quae = Cassia sect. Grimaldia (Schrank) Irwin & Barneby

Characters as given in subgeneric synopsis and sectional key above.

A complex group of 163 species, highly concentrated and diversified on the Brazilian Planalto, especially at elevations between 800 and 1200 m in the Goiás highlands and through the length of Serra do Espinhaço in Minas Gerais, but with outlying members extending to southern Mexico and the West Indies, there entirely intertropical, but two species extending in Brazil to warm-temperate Paraná and Santa Catarina (to ±27° S). For further extended commentary see under title of subsect. Absus (p. 18).