Monographs Details: Cassia conferta var. machrisiana (R.S.Cowan) H.S.Irwin & Barneby
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 machrisiana Cowan
Description:Species Description - Shrubs to 1.5 m, glabrous throughout or the branchlets and lf-margins sometimes charged with a few glandular setules (but villosulous hairs 0); lvs 2-5 cm, all 4-foliolate, the petiole 5-9 mm, the rachis 5-12 mm; lfts oblanceolate, 1-3.5 x 5-13 mm, abruptly cordate-rounded at base, on both faces smooth except for the elevated midrib and secondary venation, not reticulate; racemes subcorymbose, not or scarcely exserted, the axis 1.5-6 cm; sepals yellowish, 9-11 mm; petals yellow to 12-16 x 8-13 mm; ovary and pod glabrous, the latter reddish with pallid sutures. — Collections: 3.

Distribution and Ecology - Outcrops in cerrado, ca 1000 m, known only from the s. end of Chapada dos Veadeiros, on the head of the Piçarao fork of Rio Tocantinzinho, e.-centr. Goias. — Fl. III-V. "Type: Dawson 14598. "sandstone outcrop 7 km south of Chapada dos Veadeiros, Goias, Brazil, April 24, 1956."

Discussion:

As recognized by Cowan, C. machrisiana is closely related to C. conferta, but more especially to its var. virgata, identical in the flowers and almost so in foliage. At maturity it is apparently truly fruticose, like var. conferta and the vicariant var.simulans, not a wandlike undershrub like var. virgata. Apart from differences in habit of growth, C. machrisiana differs from var. virgata in the smoother, pinnately venulose but not reticulate leaflets and a completely glabrous inflorescence and pod, differential characters hardly specific. The two known collections agree in all details except that the type has some few setules on the young branchlets and margins of leaflets, and collectively contrast sharply in size, shape, and reticulation of leaflets with almost sympatric var. simulans.

Distribution:Goiás Brazil South America| Brazil South America|