Monographs Details: Mimosa somnians subsp. longipes (Barneby) 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.
Description:Subspecies Description - In habit resembling var. viscida, the stems virgately erect from xylopodium 4-20 dm, either unarmed subglabrous or remotely aculeate and glandular-setose, simple or paniculate and efoliate distally; lf-stks of lvs at mid-stem 10-19 cm, the petiole 7-14 cm; pinnae 2-5-jug., the rachis of longer ones (2.5-)3-6 cm, their lfts to 30—47- jug. and to (2-)2.5-7 mm long; floral bracts elliptic or lanceolate 0.6-2 mm, 1-5-nerved; calyx 0.9-1.6 mm, the delicately striate tube 0.7-1 mm, unequally 2-4-toothed, the longest tooth ovate 0.3-0.6 mm; corolla 3.1-4 mm; pods (of var. longipes) ±60 x 5 mm and ±6-seeded, at base attenuate into a stipe 1 cm, the valves glabrous, the elliptic articles 11-13 mm.
The subsp. longipes is well differentiated from other forms of M. somnians by slenderly long-petiolate leaves and by relatively large and firm-textured, unequally toothed calyx. The elongate articles of the pod, at present known only in var. longipes, are equally notable. The small known range of subsp. longipes lies within that of subsp. viscida var. viscida, which otherwise resembles it except that the stems are never aculeolate as in var. possensis.