Mimosa daleoides

  • Title

    Mimosa daleoides

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Mimosa daleoides Benth.

  • Description

    212. Mimosa daleoides Bentham, J. Bot. (Hooker) 4: 389. 1841.—"Brazil, Sello; Prov. St. Paul [Riedel commun.] Langsdorff. ’’—Lectotypus (Lins, 1984: 25), Sello s.n., K (herb. Benth.)!; isotypi, G! K (herb. Hook.)!; syntypus, Langsdorff ex herb. petrop. 169, K (herb. Benth.)!

    M. daleoides fma paraguariensis Chodat & Hassler, Bull. Herb. Boissier II, 4: 554 [=P1. hassler. 2: 410]. 1904.—"[Paraguay:] pr. Curuguaty, Sept. [Hassler] n. 4584; . . . pr. Chololo, in valle fluminis Y-aca, Dec. [Hassler] n. 6601."—Syntypi, G!; isosyntypi, A! NY! W!—M. daleoides var. paraguariensis (Chodat & Hassler) Hassler, Repert. Spec. Nov. Regni Veg. 9: 1. 1910.—Reduced to typical M. daleoides by Burkart, 1964: 361.

    M. daleoides fma psammophila Burkart, Darwiniana 13(2-4): 361. 1964.—"Brasil. Rio Grande do Sul: Osorio (nordeste maritimo del estado). .. B. Rambo 45.188, en flor 4-1-1950... .’’—Holotypus, SI, not seen.—Lins (1984: 25, in discussion) included this in M. daleoides and cited an isotypus at PACA.

    M. daleoides sensu Bentham, 1875: 411, 1876: 353, Burkart, 1948: 118, fig. 16D, 1964: 359; Lins, 1984: 24, fig. 2 + map (Rio Grande do Sul).

    Slender unarmed shrubs and subshrubs, with either ascending or diffuse (then exceptionally subradicant), distally forking or simple, relatively distant-lvd stems, tomentellous throughout with contracted stelliform and (upward, especially on peduncles and lf-stks) fine erect yellowish plumose setulae to 0.2-0.4(-0.6) mm, the foliage yellowish-green concolorous, the thick-textured lfts stellate-tomentulose on both faces, the narrowly amentiform or slenderly ellipsoid fl-spikes solitary or 2-3(-4)-nate in several or many successive lf-axils along all terminal branchlets, or late in season forming a shortly exserted pseudoraceme. Stipules erect, linear-attenuate (2-)3-7 mm, tomentulose dorsally like stem, persistent. Leaf-stalks including hard pulvinus 2-6(-9) x 0.4-0.8 mm, the ventral sulcus concealed by pubescence; pinnae 1-jug., the rachis of each 1.5- 5.5(-6) cm, the longer interfoliolar segments (1.2-)1.4-2(-3.4) mm; lfts of all but rare diminished rameal lvs 1l-21(-25)-jug., alternate along rachis, the first pair 0.8-1.6 mm distant from subulate paraphyllidia 0.2-0.5 mm, only a little decrescent at ends of rachis, the plane blades oblong or oblong-elliptic from obtusangulate base, obtuse or subapiculate, those near mid-rachis (2-)3-8.5 x 1.5-2.8 mm, (2-)2.2-3.4 times as long as wide, the slightly displaced midrib and sometimes one posterior nerve faintly raised beneath, the venation otherwise immersed. Peduncles (0.6-) 1.5-5 cm; flower-spikes cylindric or (when short) narrowly ellipsoid-ovoid, without filaments 3-4.5 mm diam., the axis (4-)5-16(-25) mm; bracts linear-oblanceolate or spatulate 0.8-2 mm, deciduous; flowers 4-merous 4-androus, subuniform in size but those below mid-axis all or mostly staminate; calyx reduced to a minute ciliolate disc ±0.2 mm diam.; corollas subglobose 1.4-1.8 mm, densely yellowish-stellate externally, the connivent deltate-triangular lobes 0.5-0.7 mm; filaments yellow, monadelphous through 0.5-0.8 mm into a cup bearing between each pair a rudimentary staminode less than 0.1 mm, the fertile ones exserted 1.6-2.3 mm; ovary tomentulose. Pods usually numerous along distal half of receptacle, sessile by cuneate base, in profile undulately linear-oblong 8-17(-24) x 2-3 mm, 2-5(-6)-seeded, densely subuniformly yellowish- or sordid-stellate overall, the constricted replum 0.3-0.45 mm wide, the firmly papery valves low-colliculate over each seed, when ripe separating from replum and breaking up into oblong-elliptic, individually dehiscent articles 3-5 mm long; seeds basipetally descending, plumply obovoid ±2-2.5 x 1.5 mm, the testa fuscous dull.

    In seasonally dry campo and in pasture thickets, ascending from near sea-level s.-ward to 1050 m in mountainous e. Paraná and to 1600 m in s.-e. Bolivia, interruptedly widespread in s.-e. Brazil from e. Rio Grande do Sul n. to and perhaps just beyond the Tropic of Capricorn in S. Paulo, w. just into Misiones and Corrientes, Argentina, thence n.-w. through Paraguay into s.- e. Bolivia (Sta. Cruz), and n. just into s.-most Mato Grosso do Sul (rio Iguatemí).—Fl. freely XII-IV, intermittently thereafter, the pods (or empty repla) often persisting on annotinous stems.

    This common and well-known species has recently been treated in detail by Burkart and by Lins. It is readily recognized among Calothamnos with conjugately pinnate leaves by yellowish-green coloration of the relatively sparse foliage, by narrow, often amentiform capitula, by basally connate filaments, and by narrow, uniformly stellate pod shallowly constricted between seeds.