Monographs Details: Mimosa gracilis subsp. filiformis var. leiocarpa (Burkart) Barneby
Authors:Rupert C. Barneby
Authority: Barneby, Rupert C. 1991. Sensitivae Censitae. A description of the genus Mimosa Linnaeus (Mimosaceae) in the New World. Mem. New York Bot. Gard. 65: 1-835.
Family:Mimosaceae
Synonyms:Mimosa selloi var. leiocarpa Burkart, Mimosa graminiformis Chodat & Hassl., Mimosa burchellii Benth., Mimosa guaranitica Chodat & Hassl., Mimosa capillipes var. capillipes
Description:Variety Description - Stems humifuse 2-6.5 dm, remotely aculeolate or sometimes unarmed; leaf-formula (i—)ii—iii(— iv)/4-9(-10); pods subsessile, 22-37 x 2.8-4.5 mm, 6-13-seeded, the replum undulately constricted between seeds, the articles 3-3.8 mm long.

Distribution and Ecology - In campo, mostly below 600 m but ascending in e. Sta. Catarina to 900 m, locally plentiful, sometimes in hard red soils, e. Paraguay s.-ward from río Apa near 22°S to n.-e. Argentina (Misiones, Corrientes), thence s.-e., perhaps interruptedly, to the sources of rio Iguaçú in Sta. Catarina, to upper Pelotas valley in Rio Grande do Sul (Bom Jesus), and n.-e. Uruguay.—Fl. XI-III. Map 21.

Discussion:

The var. leiocarpa was first described and figured by Burkart in his revision of Argentine Mimosa but was subordinated to the not very closely related M. selloi, a species at that time known to Burkart only through photographs. His mistake was acknowledged in Flora Ilustrada Catarinense, but he made no disposition of var. leiocarpa other than to suggest that it deserved specific status. I have failed to disentangle it from the complex of M. gracilis, of which it has the flower and pod, or to distinguish it at any level above that of variety from M. gracilis subsp. filiformis, which is similarly glabrous and commonly remotely aculeolate. The var. leiocarpa seems barely to differ from var. filiformis in slightly fewer pairs of leaflets, but it ranges far southward, mostly below the tropic line. It is notable that Burkart, while adhering to Bentham’s serial criteria and accordingly referring var. leiocarpa to ser. Asperatae, noted its striking likeness to M. (ser. Leptopodae) capillipes, that is to M. gracilis subsp. capillipes of this account. here interpret the fragmentary type of M. graminiformis as an etiolated stem of var. leiocarpa, perhaps drawn out in competition with taller campo grasses. It has leaf-stalks to 12 cm, petioles to 8.5 cm, interpinnal segments of leafstalk to 2 cm, and pinna-rachis to 12 mm long.

Distribution:Argentina South America| Misiones Argentina South America| Corrientes Argentina South America| Paraguay South America| Uruguay South America| Brazil South America| Rio Grande do Sul Brazil South America| Santa Catarina Brazil South America|