Monographs Details: Mimosa nitidula 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.
Synonyms:Mimosa pseudopetiolaris Barneby
Description:Species Description - Slender unarmed subshrubs with wandlike ribbed castaneous stems, including the simple virgate pseudoraceme of small globose capitula to ±12 dm tall, sparsely hispid with scattered spreading-ascending setae 0.5-1.5 mm, the brown-glaucescent concolorous lfts glabrous lustrous on both faces, continuously callous-marginate and finely setose-ciliolate, the inflorescence developing in regular acropetal sequence. Stipules firm ascending, lance-attenuate 4-7 x 0.4-0.9 mm, glabrous 3-nerved dorsally, weakly setose-ciliolate, persistent. Leaf-stalks narrowly ascending 4.5-7.5 cm, at middle 0.4-0.5 mm diam., the ventral groove open and very shallow, spicule 0; pinnae 1-jug., the rachis 4-7.5 cm, the interfoliolar segments 4-5.5 mm; lfts of longer pinnae 10-18 (of some proximal lvs only 5-8, no further described)-jug., scarcely graduated, the first pair 3—4.5 mm distant from erect subulate paraphyllidia 0.8-1.2 mm, the blades obliquely ovate from broadly semicordate base, abruptly mucronate, the larger ones 6-10 x 2.6-4.5 mm, ±2.2 times as long as wide, all veinless or almost so above, beneath 3-4-nerved from pulvinule, the gently incurved midrib displaced to divide blade ± 1:2, distally 1-2-branched, the inner posterior nerve brochidodrome beyond mid-blade, the pallid marginal nerve ±0.1 mm diam., the scattered 1-seriate cilia free for 0.2-0.7 mm. Peduncles solitary 8-18 mm; capitula without filaments 7.5 mm diam., prior to anthesis moriform, the 4-angulate fl-buds obtuse, granular at tip; bracts narrowly oblong, abruptly incurved and distally acuminate ±2 x 0.6 mm, 1-nerved, glabrous dorsally, the distal margins with minute thickened trichomes; flowers 4-merous 4-androus; calyx obsolete or almost so; corolla narrowly vase-shaped ±3.5 mm, the ovate incurved, scarcely thickened but dorsally carinate lobes ±1.1 x 0.9 mm, charged near margin with minute thickened trichomes; filaments (probably pink) free to base, exserted 6.5 mm; ovary minutely ciliolate dorsally; pod unknown.
Distribution and Ecology - In unrecorded habitat, but to be sought in treeless campo, known only from the type-collection, surmised to originate in department of Cordillera, Paraguay.—Fl. XII(-?).
This and the next following differ from other Brevipedes in their relatively few, distant and long- petiolate leaves. They may be misplaced in the subseries, but I can find no more appropriate affiliation in ser. Mimosa. Specific characters of M. nitidula in this setting are the wandlike growth- habit and relatively numerous and small, lustrous leaflets which forcefully recall those of the microphyllidious varieties of M. dolens found in southeastern Paraguay, one of which may have played a part in its genesis. It is known at present from the one collection cited, the origin of which is not precisely recorded.
Distribution:Paraguay South America
| Cordillera Paraguay South America