Monographs Details: Mimosa pseudotrachycarpa 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 trachycarpa Benth.
Description:Species Description - Stiffly branched microphyllous shrubs attaining 9-12(-?) dm, armed either close below or far below each node with one infrapetiolar and two infrastipular, straight or recurved, stout vulnerant aculei 3-5.5 mm (one or more of each triad sometimes wanting), the young stems, lf-stks and peduncles densely viscid-puberulent with minute, forwardly incurved hairs and erect gland-tipped setulae 0.1-0.2 mm tall, the foliage (dry) brown-olivaceous concolorous, the thick-textured plane lfts glabrous on ventral or on both faces, minutely ciliolate, the globose or plumply ellipsoid capitula single in primary lf-axils or in lf-axils of a succession of lateral short-shoots, forming an effuse leafy thyrse or panicle. Stipules firm ovate-deltate 1-2 x 1-2 mm, those of primary lvs spreading-recurved, ventrally convex, becoming dry deciduous, those of axillary brachyblasts smaller ascending. Leaf-stalks (1-)2-11 mm, the petiole often reduced to livid pulvinus, potentially attaining 2 mm, the interpinnal segments 0.5-4 mm, the ventral groove continuous (spicules 0); pinnae of most lvs 2-4-jug. (of some small distal lvs 1-jug., no further described), accrescent distally, the rachis of furthest pair 5-9.5 mm, the interfoliolar segments 0.4-1 mm; lfts of distal pinnae 7-12(-13)-jug., sube- quilong except at base of rachis, the first pair 0.2-1.2 mm distant from ovate paraphyllidia 0.30.5 mm, the blades oblong obtuse from semicordate base, the longer ones 2-3 x 0.85-1.2 mm, 2-3 times as long as wide, the venation immersed. Peduncles 5-30 mm; capitula without filaments ±7 x 5-6 mm, prior to anthesis moriform, the plumply obovoid fl-buds either glabrous or gray-puberulent; bracts elliptic or oblanceolate 1-1.5 x 0.3-0.6 mm, either puberulent dorsally or merely ciliolate, caducous; flowers 4-merous 8-androus, all or almost all bisexual; calyx submembranous campanulate 0.6-0.8 mm, externally either glabrous or puberulent, the broadly triangular or depressed-deltate teeth 0.1-0.25 mm, the rim microscopically ciliolate; corolla narrowly turbinate 2.1-3 mm, the membranous, shallowly concave, ovate lobes 0.7-1 x 0.8 mm, the central nerve faintly branched; filaments lilac-pink, united at very base into a stemonozone below the ovary, exserted 4-5.5 mm; pod not seen.

Distribution and Ecology - In dry stony campo and at edge of gallery woodland, best known from ±700-900 m in n.- e. Paraná (Jaguariaiva, Arapoti, Ponta Grossa), Brazil; not reported from Sta. Catarina (Burkart, 1979), but reappearing near 700 m in n.-e. Rio Grande do Sul (mun. Vaccaria).—Fl. IX-XII(- ?).

Discussion:

The type-collection of M. pseudotrachycarpa was misidentified by Dusen as M. trachycarpa Bentham, a name that is here interpreted as a synonym of M. cruenta Bentham. From the latter it is clearly different in strongly or at least incipiently revolute stipules and in almost nerveless leaflets.

Distribution:Brazil South America| Santa Catarina Brazil South America| Rio Grande do Sul Brazil South America| ParanĂ¡ Brazil South America|