Mimosa glanduliseta

  • Title

    Mimosa glanduliseta

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Mimosa glanduliseta Burkart

  • Description

    145. Mimosa glanduliseta Burkart, Darwiniana 8(1): 58, fig. 5. 1948.—“Argentina. Misiones: Bonpland ... E. L. Ekman 1630, 26.XII.1907.. . .’’—Holotypus, S (not seen); isotypi, MO! NY!; paratypi, Fiebrig 5901, G! GH!

    Slender microphyllidious shrubs or subshrubs 5(-?) dm tall, viscid throughout with erect gland-tipped setulae 0.1-0.4 mm tall and armed on subterete intemodes and along dorsal and lateral ribs of lf-stks with scattered slender, stramineous or brown, subrecurved aculei 0.5-1.5 mm, the sparse foliage olivaceous concolorous, the faces of lfts densely sprinkled with minute sessile or subsessile glands, the small ellipsoid capitula solitary or rarely geminate at random lf-axils on a capillary peduncle about as long as subtending lf. Stipules ascending or subdeflexed, herbaceous ovate-triangular 1.5-3.5 x 0.5-1.2 mm, slenderly 3-6-nerved, persistent. Leaf-stalks 2-6 (of flowering branchlets seldom over 3) cm, the petiole to ±5-7 x 0.25-0.4 mm and the interpinnal segments about as long, the narrow ventral sulcus interrupted between pinnae by a livid-glandular bridge but true spicule 0, the terminal appendage lanceolate foliaceous; pinnae 4-6(-7)-jug., accrescent distally, the rachis of longer ones 10-23 mm, the interfoliolar segments ±0.5 mm; lfts of longer pinnae 8-13(-15)-jug., subequilong, the first pair 0.6-1.1 mm distant from ovate-subor-bicular green paraphyllidia 0.3-0.5 mm, the blades oblong or linear-oblong obtuse from obliquely obtusangulate base, the larger ones 1.8-3.5 x 0.6-1.3 mm, ±2.5-3.5 times as long as wide, all veinless above, beneath faintly l(-2)-nerved from pulvinule, the immersed midrib subcentric, the margin minutely gland-fimbriolate. Peduncles 2.5—3.5 cm; capitula without filaments 8—11 x 5.5—6 mm, prior to anthesis moriform; bracts oblanceolate or linear-spatulate 0.7-1.3 x 0.2-0.4 mm, deciduous; flowers 4-merous 8-androus, some lower ones staminate; calyx shallowly campanulate 0.3-0.4 mm, the rim entire or obscurely denticulate, either glabrous or fimbriolate with minute setulae 0.1-0.2 mm; corolla funnelform 1.9-2.4 mm, the ovate lobes 0.8-1 x 0.6 mm, a little thickened at very apex, densely minutely glandular-setulose externally; filaments pink, free to base, exserted 6.5-8.5 mm. Pods ±1-6 per capitulum, in profile undulately linear (2-)2.5-3.5(-4) cm x 3—4 mm, 6-10(-12)-seeded, at base tapering into a stipe or pseudostipe ± 2 mm and at apex into a slender cusp 1-2.5 mm, the replum 0.4-0.5 mm diam., the valves bullately raised over each seed, the replum and valves alike densely minutely viscid-setulose overall and the valves in addition hispid with stronger pallid setae to 0.6-1.2 mm crowded toward middle of each article, the ripe valves fuscous-brown papery, breaking up into free-falling, individually dehiscent articles 2.5-3 mm long; seeds obliquely basipetal, obtusely rhombic-lentiform ±2.5 x 2-2.2 mm, the fuscous-brown testa sublustrous.

    In dry stony campo and at edge of thickets, below 250 m, known only from the lower Paraná valley in s.-e. Paraguay (depto. Alto Paraná, without precise locality) and adj. Misiones, Argentina (Sta. Ana; Bonpland).—Fl. X-I(-?).

    Mimosa glanduliseta appears fully distinct from sympatric and nearly sympatric Stipellares in aculeate stems and ellipsoid capitula. As noted by Burkart, this combination of characters recalls M. (ser. Glandulosae) adenocarpa, but the dilated paraphyllidia and lack of interpinnal spicules are decisive differences.