Monographs Details: Mimosa suburbana 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 diplotricha C.Wright ex Sauvalle
Description:Species Description - Slender, diffusely ascending or scrambling subshrubs to ±8-11 dm, the sharply trigonous, internally pithy stems densely armed along ribs with recurved stramineous brown-tipped aculeoli to 0.5-1 mm, otherwise glabrous except for minutely puberulent lf-axes and pulvini, the thin-textured lfts bicolored, olivaceous above, pallid beneath, the small globose capitula borne on filiform peduncle either directly from lf-axils or on short leafless axillary branchlets, in either case much shorter than subtending lf. Stipules erect or deflexed, narrowly subulate 1.2-2.5 mm, 1-nerved. Leaf-stalks (4-)5-8.5 cm, aculeolate dorsally like stem, the subterete petiole 25-55 x 0.5 mm, the longer interpinnal segments 7-14 mm, the pulvini (commonly livid, evidently sensitive) of each pair of pinnae separated by a 1-2-spiculate bridge; pinnae (3-)4(-5)-jug., subequilong, the rachis 2.5-5.5 mm, the longer interfoliolar segments 1-1.4 mm; lfts 23-31-jug., the first pair 0.8-1.5 mm distant from minute subulate paraphyllidia, except for small proximal pairs subequilong, the blades in outline linear subacute (3.5-)4-7 x 0.75-1.2 mm, faintly 2(- 3)-nerved from pulvinule, the midrib subcentric, the outer venule(s) expiring well below mid-blade. Peduncles (12—) 15—30 x 0.1-0.15 mm; capitula globose, without filaments 3—4 mm diam., prior to anthesis moriform, the plumply obovoid fl- buds glabrous or minutely papillose-puberulent; bracts ovate-elliptic ±0.4—0.65 mm; fls 4-merous 8-androus, the lower ones staminate, few distal ones bisexual; calyx membranous campanulate ±0.4—0.5 mm, broadly short-toothed, the orifice beaded with minute reddish granules; corolla reddish, broadly turbinate 2—2.5 mm, the membranous, weakly 1-nerved lobes lanceolate or lance-ovate, distinctly longer than the tube; filaments pink, monadelphous through 0.1 mm below glabrous ovary, exserted 3—3.5 mm. Pods 1-2 per capitulum, stipitate, the slender stipe 0.4-6 mm, the piano-compressed body in profile broad-linear from cuneate base, 35-40 x 5.5-6.5 mm, 8-10-seeded, the subundulate replum 0.2-0.35 mm wide, apiculate distally, armed (sometimes discontinuously) with recurved aculeoli 0.2-0.6 mm, the papery, pale green or at length stramineous, glabrous, exiguously venulose valves low-colliculate over seeds, breaking up when ripe into free-falling articles 4-5 mm long; ripe seeds not seen.
Distribution and Ecology - In disturbed cerrado thickets and at edge of gallery forest, ±950-1100 m, apparently local (but inconspicuous, perhaps overlooked) in Distrito Federal, Brazil (Parque do Gama; Fda. Fazendeira; road to Unaí), to be sought in adj. Goiás and far w. Minas Gerais.—Fl. III-VI(-?). Map 22.
A slender prickly mimosa resembling common M. diplotricha in habit, M. suburbana is sharply distinguished by trigonous (not 4-5- ribbed) stems, capillary peduncles, corollas lobed to well below middle, and particularly by the pods. These are borne one or two together in a capitulum and not in dense umbelliform clusters and are slenderly stipitate, not sessile; moreover the valves are glabrous and one third to one half wider. Mimosa selloi, a close relative with similarly stipitate pods, has subterete or obscurely 5-ribbed stems, only two or three (not in most leaves four) pairs of pinnae, larger leaflets, and capitula excluding the filaments 5-6, not 3-4 mm diam.
Distribution:Brazil South America
| Minas Gerais Brazil South America
| Goiás Brazil South America
| Distrito Federal Brazil South America