Mimosa

  • 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

  • Type

    394bis. Mimosa sp.—Brazil. Bahia: in cerrado at 600 m, 8 km n.-w. of Barreiras toward Sta. Rita de Cássia, valley of rio das Ondas, 3.III.1971, Irwin (with Harley & G. L. Smith) 31431 (G, K, NY, R, UB, US, mostly sterile leafy stems).

  • Description

    Species Description - Stout erect few-branched shrubs 2.5 m with dark defoliate trunks and densely long-lvd developing branches, strigose throughout with forwardly appressed setae, those of stems and lf-stks scaberulous, those of lft-faces smooth or almost so, the firm glaucescent lfts coarsely continuously callous-marginate and appressed-ciliolate, the inflorescence unknown. Stipules firm, narrowly lanceolate 2-4 x 0.5 mm, densely strigose dorsally, glabrous castaneous within. Leafstalks reduced to pulvinus or almost so, 1-3 mm; pinnae 1-jug., the rachis 8-14 cm, the interfoliolar segments 2.5-4 mm, paraphyllidia 0; lfts 3347-jug., the small unequal first pair close to pulvinus, the blades lance-oblong from semicordate base, abruptly deltate-apiculate, those near mid- rachis 8.5-16 x 2.2-4 mm. (3.2-)3.5-4.5 times as long as wide, all veinless above, beneath 4-6- nerved from pulvinule, the midrib strongly displaced, the innermost posterior nerve produced almost to blade apex, the outer ones progressively shorter. Fruiting peduncles solitary 1-1.5 cm; fresh flowers unknown, but dried fragments suggestive of M. hypoleuca, the calyx certainly paleaceous. Pods (fragmentary) 3-4-seeded, the replum ascending-setose ±0.5 mm wide, otherwise unknown.

  • Discussion

    This differs from M. hypoglauca in stem-pubescence of barbellate setae, in very long pinnae (8-14, not 6-9 cm), and in leaflets pubescent on both faces. The specimens do not provide good comparisons with the distantly allopatric M. callithrix, but differ materially in leaves all sessile and leaflet-indumentum of simple smooth setae.