Monographs Details: Mimosa egregia Sandwith
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.
Scientific Name:Mimosa egregia Sandwith
Description:Species Description - Macrophyllidious drought-deciduous shrubs attaining 1.5-4 m, either unarmed or randomly armed on few internodes with 1-2 stout recurved aculei ±3-5 mm, the young branches, lvs and inflorescence silky-pilosulous or -tomentulose with fine shining, mostly dense and spreading but on upper face of lfts thinner, subappressed hairs, the ample lfts pale green, a little paler on lower face, the inflorescence an efoliate or basally few-lvd pseudoraceme of amentiform spikes 1-4 dm above foliage. Stipules firm lanceolate 26 mm, bluntly 1 -nerved or almost nerveless. Leaf- formula ii—iii/1—2, the lf-stks 6-12 cm, the ventral sulcus either continuous between pinnae or weakly bridged and then sometimes charged with 1-2 small pallid spicules; pinnae either subequilong and all bifoliolate, or accrescent upward and the distal pair then 4-foliolate, the rachis of the latter 1-5.5 cm; lfts obliquely obovate, either obtuse mucronulate or depressed-acuminulate at apex, the larger ones ±3-6 x 2-4.5 cm, all (3-) 4-5-nerved from pulvinule, the forwardly curved midrib pinnately 5-7-branched on each side, the inner posterior nerve similarly pinnate and produced well beyond mid-blade, the secondary and tertiary nervules pallidly discolored on both faces of blade but sharply prominulous only on lower one. Flower-spikes verticillate by 2-5(-7), without filaments 4.5-5 mm diam., the pliant axis, including peduncle, 6-11 cm; bracts less than 1.5 mm, caducous; fl-buds obovoid, densely pallid- sericeous; flowers sessile, 5-merous 10-androus, all bisexual; calyx membranous campanulate 0.8-1 mm, weakly 5-nerved, the depressed-deltate teeth 0.1-0.15 mm; corolla 2.1-2.4 mm, cleft ± half-way, the 1-nerved lobes at first ascending, recurved in age; filaments pale pink fading whitish, at very base united to corolla, exserted 4-6 mm; ovary sericeous after fertilization. Pods scattered along spike-axis, sessile or almost so, in profile linear or linear-oblong, straight or gently curved, 25-45 x 4-8.5 mm, 5-8-seeded, the shallowly undulate or nearly straight replum ±0.4 mm thick, the replum and valves alike densely pilosulous and randomly granulate overall, the valves bullately elevated over each seed, when ripe becoming papery stramineous and breaking up into free-falling, individually indehiscent articles 4.5-6 mm long, either broader or narrower than long.

Distribution and Ecology - On dry brushy hillsides at elevations not recorded, apparently local, known only from the Balsas Basin in s.-e. Mexico (Temascaltepec) and Guerrero (Coyuca), Mexico.—Fl. VI-VIII.


Remarkable for few, very large leaflets, in which it differs from related M. guatemalensis and M. spirocarpa. It has the fruit of the former, but almost the leaf-formula of the latter.

Distribution:Mexico North America| Guerrero Mexico North America| México Mexico North America|

Narratives:Mimosa egregia