Monographs Details: Macrolobium suaveolens Spruce ex Benth. var. suaveolens
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:Species Description - Shrub to 5 m. tall or small tree, the branchlets and leaves glabrous. Petioles 5-6 mm. long. Leaflets 8-11.5 cm. long, 3-4 cm. wide, falcate, the apex acuminate with the extremity obtuse, the upper margin nearly straight, the lower arcuate; costa plane above, salient beneath, the venules prominulous. Inflorescences 4.5-6.5 cm. long, the peduncle about 1 mm. long; bracts 1.5 mm. long, 1 mm. wide, ovate, acuminate, glabrous except for the ciliolate margins; pedicels 1-3-5 mm. long, sparsely and minutely puberulous; bracteoles 5-6 mm. long, 3~3.5 mm. wide, oblong, minutely apiculate, glabrous within, externally minutely puberulous at least on the apex and costa. Sepals dimorphic, the adaxial ones 1-1.5 mm. long, about 1 mm. wide, triangular, acute, the others 2.5 mm. long, 1.5 mm. wide, oblong-lanceolate, acute, glabrous. Petal blade about 4 mm. in diameter, orbicular, the claw 4 mm. long, broader at the base but not auriculate. Filaments 16 mm. long. Stigma peltate. Style 11 mm. long, glabrous. Ovary 2 mm. long, 1 mm. wide, glabrous, oblong, the gynophore 2.5 mm. long, pilosulose on the adaxial surface.

Discussion:

Vouapa suaveolens (Spruce ex Benth.) Taub. Bot. Centralbl. 47: 394. 1891.

Vuapa suaveolens (Spruce ex Benth.) Kuntze, Rev. Gen. 1: 213. 1891.

Type Collection: R. Spruce 2771, "In sylvis 'Caatingas'... fluv. Uaupes," Brazil, Nov. 1852 (HOLOTYPE K, isotypes F, G, GH, NY, P, W).

The relationships of this species are not particularly well defined but it is perhaps more nearly related to M. amplexans than to any other species. It may be distinguished by its minutely puberulous branchlets, ramiflorous inflorescences, and four-parted calyx.

The prime character utilized in segregating the varieties is the distribution of the pubescence on the ovary. The ovary of varieties pakarimense and rondonianum is puberulous on all surfaces, while that of varieties petiolatum and uaupesense is puberulous only on the margins, and the ovary of the typical variety is completely glabrous.