Monographs Details: Cassia orbiculata Benth. var. orbiculata
Authors:Howard S. Irwin, Rupert C. Barneby
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.
Family:Caesalpiniaceae
Synonyms:Cassia orbiculata Benth.
Description:Species Description - Lfts (2-3 pairs) glabrous, puberulent dorsally near the pulvinus, or thinly villosulous both sides, loosely reticulate, the areoles mostly >1.5 mm diam; inflorescence viscid-villosulous and -setulose or simply setulose, the setules not more than 0.5(-0.8) mm long. — Collections: 44. Cerrados, exposed rocky creek-banks, and margins of gallery forests, on sandstone, red soils, or occasionally on limestone, (800-)850-1175(-1300) m, locally plentiful in e.-centr. and s.-e. Goias and adjoining Bahia and Minas Gerais, extending from upper Rio Preto (11°S) s. through Espigao Mestre and Chapada dos Veadeiros to Sa. dos Pireneus and Piracanjuba (near 17° 30'), w. into s. -centr. Mato Grosso near 19° S (R. Verde), rarely e. to the Sao Francisco-Velhas valley in Minas Gerais (Curvelo). - Fl. III-VIII.

Distribution and Ecology - "In Claussen's collection."

Discussion:

One of the commonest cassias of the Goias highlands, a characteristic, often locally abundant element of the cerrado scrub forest. Our colleague Robert Goodland (pers. comm.) found it present in 67 out of 200 sites within Distrito Federal studied ecologically in 1971, dominant in three of these, and in one site (3.1 km. e. of Rio Piporopau, 1150 m) attaining an importance value of 21.84 p.c.

The range of C. orbiculata as given in Flora Brasiliensis (Bentham, 1870, p. 79) is unrealis- tically extensive. Gardner's collection attributed to Pernambuco originated in northwestern Bahia, as shown by the date and locality (Santa Rita, not "Sta. Rosa", Rio Preto, Sept. 1839) recorded on labels of duplicates not seen by Bentham. The type-locality, in view of the known dispersal of the species, is also under suspicion. Claussen had already acquired his fazenda near Curvelo before he started collecting plants at Lund's suggestion, and Caxoeira do Campo was his place of business. What appears, from identical stage of anthesis, discoloration of leaves, etc., to be isotypic material, even though passing under a different number (849) is a sheet at Paris actually labelled Curvelo. Even this would be the only indication that typical C. orbiculata occurs to the east of Rio Sao Francisco.

Distribution:Goiás Brazil South America| Distrito Federal Brazil South America| Brazil South America|