Monographs Details: Mimosa rava 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 auriberbis Barneby
Description:Species Description - Erect unarmed, awkwardly branched, densely foliolate shrublets 3-5 dm, densely villosulous and hispid with fine erect gray villi less than 0.5 mm and spreading-ascending strong yellowish setae to 2-3.5 mm, at times mixed with random minute gland-tipped setulae, the small crowded lfts softly pubescent on both faces, weakly setose-ciliolate, the inflorescence a small leafy-bracteate or shortly exserted pseudoraceme of subglobose capitula. Stipules stiffly erect, narrowly lance-attenuate 4-9 x 0.5-0.9 mm, pubescent both within and without, persistent. Leaf-stalks 2-5.5 cm, the discolored pulvinus and petiole together 3-6 mm, the longer interpinnal segments 5-10 mm, the ventral groove continuous between pinna-pairs (spicules 0); pinnae 4-7(-8)-jug., accrescent distally, the rachis of furthest pair 25-55 mm, the longer interfoliolar segments ± 1 mm; lfts of distal pinnae 26-47-jug., the proximal pair not more than 0.5 mm distant from a pair of subulate or subfoliaceous paraphyllidia, all in outline linear-oblong obtuse, the longer ones 4.5-5.5 x 0.9-1.2 mm, at maturity faintly 3-nerved dorsally. Peduncles both solitary and geminate 2-4 cm; capitula without filaments 9-11 mm diam., prior to anthesis hispid with emergent bracts; bracts linear-attenuate 3-6 x 0.3-0.5 mm, setose dorsally and setose-ciliate; flowers 4-5-merous diplostemonous, the proximal ones staminate and a little shorter than the rest; calyx-tube 0.4-0.5 mm, ciliate around the vestigial pedicel and both around and externally just below the rim with fine setae to ±1 mm; corolla 3.8-5.2 mm, the funnelform tube glabrous externally, the ovate, subapically callous lobes 1.3-1.5 mm, loosely finely setulose dorsally; filaments pale pink, monadelphous through 0.8-1.1 mm, exserted to 7-9 mm. Pods 1-3 per capitulum, sessile, in profile oblong or oblong-elliptic 30-50 x 10 mm, strongly compressed, the replum ±1-1.3 mm wide, commonly contracted at apex into a stout cusp 1-3 mm (this sometimes 0), the valves (not seen fully ripe) low-colliculate over ±9—12 transverse seeds, composed of livid exocarp and stiffly papery endocarp each ±0.1 mm thick, the valves and replum alike variably villosulous but equably hispid overall with stout ascending tapered yellowish setae ± 2-4 mm; dehiscence and seeds not seen, but the valves most probably detached entire from replum.
Distribution and Ecology - On dry hillsides in cerrado, 700-1000 m, known only from the type-locality on sources of rio S. Bartolomeu in Distrito Federal, Brazil.— Fl. VIII-IX.
Mimosa rava and M. auriberbis, which were collected together and are known only from this one place, seem closely related, but are so different in leaf-formula (as given in diagnosis), as well as in quality of leaf-pubescence, form of stipules and size of capitula, that it seems impossible to conceive of them as conspecific. The plants bear a strong resemblance in habit to the more paucipinnate forms of M. foliolosa var. foederalis, but the leaflets are much more numerous, more crowded, and densely villosulous on both faces. Nevertheless, when better known, M. rava may emerge as no more than an extreme satellite of the M. foliolosa complex. Pentamerous flowers in this species seem to occur only at random among more normal tetramerous ones.
Distribution:Brazil South America
| Distrito Federal Brazil South America