Monographs Details: Mimosa paraibana 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
Scientific Name:Mimosa paraibana Barneby
Synonyms:Mimosa platycarpa Benth.
Description:Species Description - Amply leafy, xerophytic but not notably xeromorphic subsarmentose shrubs and slender trees attaining 9 m, either randomly armed on internodes and along dorsal rib of some lf-stks with recurved aculei 0.5-1.5 mm or some leafy stems unarmed, the homotinous branchlets, foliage and axes of inflorescence villosulous with soft, spreading or incumbent, whitish hairs to 0.1-0.3 mm mixed (especially at stem-nodes) with minute livid granules, the lfts when dry either dull brown-olivaceous on both faces or pallid beneath, puberulent on both faces, the globose or plumply ellipsoid or oblong capitula fasciculate in distal lf-axils, forming an exserted pseudoraceme only in very early anthesis. Stipules firm, erect-incurved, narrowly lanceolate ±3-6 x 0.3-0.7 mm, puberulent both within and without, tardily deciduous. Leaf-stalks (reddish when fresh) 3.5-9.5(-10) cm, the petiole including livid pulvinus 1.5—4.5 cm, at middle 0.6—1 mm diam., bluntly carinate dorsally and laterally, openly grooved ventrally, the interpinnal segments 4— 15 mm, the groove interrupted between pinna-pairs by a short spicule; pinnae 4-7-jug., accrescent distally, the rachis of furthest pair 2.5-5.5 cm, the longer interfoliolar segments 2.5—4 mm; lfts of distal pinnae 8-16-jug., on slender livid pulvinule 0.3-0.5 mm, either subequilong or markedly accrescent upward, the small first pair 1-3.5 mm distant from subdeflexed subulate paraphyllidia 0.3—0.5 mm, the larger blades obliquely oblong-obovate from semicordate or obtusangulate base, 5-11 x 2-4.3 mm, ±2.2-3.4 times as long as wide, at apex broadly rounded but minutely apiculate, veinless above, beneath slenderly 3-nerved from pulvinule, the forwardly displaced costa dividing blade 1:2-2.5 and giving rise on each side to 2-4 secondary venules brochidodrome well within the margin, the inner posterior vein produced to mid-blade or beyond, the outer one(s) weak and short. Peduncles 1-2.5 cm; capitula without filaments 5-7 mm diam., prior to anthesis moriform, the axis becoming 2-7(-16) mm; bracts membranous oblanceolate ±0.3-0.9 x 0.2 mm, either deciduous or subpersistent; flowers 4-merous 8-androus, many proximal ones staminate; calyx submembranous campanulate 0.7-1.3 x 0.6-0.7 mm, externally either glabrous or puberulent, the very short lobes depressed-deltate; corolla membranous vase-shaped or narrowly turbinate, the bisexual ones 2.1-3.1 mm, their ovate acute 1-nerved lobes 0.8-1.3 x 0.6-0.8 mm, minutely puberulent at tip; filaments pink, free from base, exserted 3.5-5.5 mm. Pods 1-4 per capitulum, shortly stipitate, the stipe 1-3 mm, the body broadly oblong rounded at both ends 50-60 x 17-28 mm, planocompressed except for a colliculus over each of 8-10 seeds, the replum 0.5-0.7 mm wide, abruptly produced at apex into an erect, sometimes deciduous cusp 2.5-4 mm, the papery valves reddish drying brown, minutely thinly puberulent and densely minutely glandular-punctate, not seen fully ripe but apparently separating from replum and certainly breaking up into articles 5-6.5 mm long, hence nearly thrice as broad as long; seeds not seen.

Distribution and Ecology - In caatinga and disturbed semideciduous woodland, sometimes locally abundant on granitic substrates, endemic to n.-e. Brazil, from centr. Maranhão e. to n.-centr. Pernambuco, n. to n. Ceará.-Fl. III-V, VIII, XII, the full cycle unknown. Map 15.

Discussion:

Mimosa paraibana has the general organization of M. bimucronata, but differs at anthesis in broader leaflets and pink filaments, and is unmistakable when bearing the broad papery pods, unlike those of any sympatric member of the genus.

Distribution:Brazil South America| Pernambuco Brazil South America| Maranhão Brazil South America| Ceará Brazil South America|

Narratives:Mimosa paraibana