Monographs Details: Macrolobium campestre var. arirambense R.S.Cowan
Authority: Cowan, Richard S. 1953. A taxonomic revision of the genus Macrolobium (Leguminosae-Caesalpinioideae). Mem. New York Bot. Gard. 8 (1): 257-342.
Family:Caesalpiniaceae
Description:Latin Diagnosis - Ramuli minute puberuli. Petiolus 10-20 mm. longus, leviter sulcatus. Foliorum lamina 2-3-jugata, paripinnata; rachibus 15-40 mm. longis, leviter sulcatis. Foliola 4-6.5 cm. longa, 2-3 cm. lata, ovalia ad elliptica, ad basim obtusa, ad apicem abrupte acuta, extremitate acuta. Inflorescentiae 25-28 cm. longae, axe brevipilosulo; bracteis 8 mm. longis, 3 mm. latis, elliptico-lanceolatis, acuminatis, intus glabris, extus brevi-pilosulis; bracteolis glabris intus, extus pilosis. Flores immaturi vel ab insectis vastati. Fructus (nimis maturus) circa 6 cm. longus, 3 cm. Iatus, oblongus, glaber, carpophoro 10 mm. longo, glabro.

Discussion:

Type Collection: A. Ducke 14848, "campos do Ariramba, Rio Trombetas," Para, Brazil, Sept. 1913 (HOLOTYPE G, isotype G).