Mimosa scabrella Benth.

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 scabrella Benth.

Type

205. Mimosa scabrella Bentham, J. Bot. (Hooker) 4: 387. 1841.-"Brasilia, Sello"-Holotypus, Sello s.n., K (hb. Benth.)! = NY Neg. 1846; isotypi, Sello 4450, +B = F Neg. 1370, Sello s.n., BM! NY! P! W! M. scabrella sensu Bentham, 1875: 410, 1876: 350 (exclu

Synonyms

Mimosa bracaatinga Hoehne, Mimosa bracaatinga var. aspericarpa Hoehne, Mimosa bracaatinga f. paucijuga Hoehne, Mimosa verrucosa Benth.

Description

Species Description - Unarmed trees of rapid growth, attaining 20 m or sometimes more with trunk to 4 dm diam. and broad low-convex crown of foliage, the brittle reddish-brown annotinous branchlets, lf-stks and peduncles scabrous with erect, densely plumulose setulae 0.1-0.4(-0.5) mm sometimes mostly contracted into lepidote stellae, the dense but variably ample foliage decisively or weakly bicolored, the lfts gray-stellate beneath, usually less densely so or rarely subglabrous above, the usually numerous globose or shortly oblong-ellipsoid capitula for the most part axillary but at times some distal ones shortly pseudoracemose, the long-persistent fruits immersed in foliage and often retained on annotinous defoliate branchlets. Stipules lanceolate or linear 2.5-7 x 0.5-1.3 mm, caducous usually before maturity of associated lf. Leaf-stalks mostly 3.5-9 cm, of some small early and few depauperate distal lvs shorter (no further described), the petiole 1.5-4 cm, at middle 0.5-1.1 mm diam., the longer interpinnal segments 5-13(-20) mm; pinnae of lvs on flowering branches 3-8(-9)-, on some vigorous nonflowering shoots to 14-jug., usually a little accrescent distally, the axis of longer ones 3-8(-9) cm, their longer interfoliolar segments 1—3.3(—4) mm; lfts of distal pinnae (12-) 15-32-jug., decrescent only at very ends of rachis, the first pair (0.1-)0.3-0.8 mm distant from subulate or narrowly ovate paraphyllidia 0.5-1.2 mm, the blades narrowly oblong or oblong-elliptic obtuse from semicordate or obtusangulate base, those near mid-rachis usually 3.5-9 x 1.2-2.7 mm, on Mt. Itatiaia in Rio de Janeiro attaining 12-14 x 4 mm, in either case 2.7-3.9 times as long as wide, the venation of smaller lfts concealed by gray indumentum, the subcentric costa of ampler ones and sometimes a short posterior nerve weakly raised beneath. Peduncles solitary or mostly 2-3-nate, 6-20 mm; capitula without filaments 5-12 x (4.5-)5-8mm, 1-1.5 times as long as diam., prior to anthesis moriform, the densely creamy- or yellowish-silky-strigulose, obovoid fl-buds surpassing the oblong-oblanceolate obtuse or apiculate bracts, these 0.7-1.8 mm, dorsally tomentulose distally, persistent; flowers 4-merous 4-androus, a few random ones (not seen) reportedly 5-androus, some proximal ones staminate; calyx membranous campanulate 0.4-0.8 mm, glabrous externally, the truncate or broadly low-denticulate orifice minutely ciliolate; corollas 2.2-2.9 mm, the firm ovate concave lobes 0.7-1.3 x 0.7-0.9 mm; filaments sulfur-yellow, monadelphous with intervening subulate staminodia into a cup 0.7-1.3 mm enveloping the puberulent ovary, exserted 3.5—4.5 mm. Pods usually several per capitulum, sessile, in profile broad-linear, abruptly apiculate, 15-42 x (5-)6- 8(-9) mm, the replum 0.5-0.8 mm wide, obscurely or not at all constricted between seeds, the epidermis of stiffly papery low-convex valves concealed by a coat of contracted verruciform or stelliform brownish setulae, when ripe breaking into individually dehiscent articles 5-7 mm long; seeds (described by Boelke, Darwiniana 7(2): 255, in clave. 1946, sub M. bracaatinga) 4.2-6.4 x 3.7-4.6 mm, the testa black, the cotyledons green.

Distribution and Ecology - A characteristic tree of disturbed woodland and Araucaria forest in the mountains and campos of extratropical s.-e. Brazil n.-ward from centr. Rio Grande do Sul, in places forming a closed woodland called bracaatingal, extending only weakly across the Tropic of Capricorn, at 700-1900 m, along Sa. do Mar into the e. lobe of S. Paulo (Cunha) and along Sa. da Mantiqueira to Mt. Itatiaia in w. Rio de Janeiro; cultivated in Brasília and doubtless elsewhere in tropical Brazil; widely planted for ornament, fuel, pulp and charcoal in Central and n. S. America and in the Old World tropics.-Fl. in Brazil (VII-)VIII-I(- III), perhaps intermittently later .—Bracaatinga; abaracaatinga; paracaatinga.

Discussion

The morphology, dispersal and economic virtues of M. scabrella have been most fully described by Burkart and by Lins in the places cited above. A curious form under cultivation in Paraná (mun. Bocaiva do Sul, Moreira & A. Miguel s.n., NY) has pod-valves grossly verrucose as well as stellate.

Burkart (1948: 225) plausibly suggested that the type-locality of M. scabrella is near Lages in Sta.  Catarina, where Sello must have encountered it on his fifth voyage.

Distribution

Brazil South America| Rio de Janeiro Brazil South America| São Paulo Brazil South America| Rio Grande do Sul Brazil South America|