Barneby & Isely drawing
Drawings scanned from Barneby & Isely 1986 [p. 121].

M. aculeaticarpa var. biuncifera & M. texana

by Bob Harms  email-here
A proposal to split M. biuncifera into two species by Rupert Barneby and Duane Isely ("Reevaluation of Mimosa biuncifera and M. texana (LEGUMINOSAE: MIMOSOIDEAE)," Brittonia 38 (1986) has gained general acceptance, although their M. biuncifera is now recognized as M. aculeaticarpa var. biuncifera. The split species are distinguished as follows (p. 119):

M. biuncifera (= M. aculeaticarpa var. biuncifera): Long-shoots armed at all or most nodes with 1 (2) infrastipular aculei (cf. above drawings) inserted at one or both sides of the rib leading to the petiole and on the ribs leading to the stipules; pinnae of primary leaves 3-9 pairs and leaflets of their longer pinnae (7) 8-14 pairs; corolla strigulose or puberulent; pod commonly decurved and its replum undulately constricted between seeds.

M. texana: Long-shoots armed at all or at random nodes with a singular aculeus inserted on the rib leading to and immediately below the petiole (at rare nodes 1 or 2 infrastipular aculei also present); pinnae of all leaves 1-4 ... pairs and leaflets of even the longest pinnae no more than 7 pairs; corolla externally glabrous, the lobes sometimes minutely fimbriolate at tip; pod commonly straight or only slightly decurved, its replum scarcely constricted between developed seeds though deeply so where ovules abort.

M.tex prickle
M. texana		 M.aculeaticarpa prickle1 M.acul. prickle 3
M. aculeaticarpa var. biuncifera

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