Monographs Details: Mimosa decorticans 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 setosissima Taub., Mimosa densa Benth.
Description:Species Description - Amply leafy microphyllidious arborescent shrubs and treelets 2-3.5 m with trunk attaining 1 dm diam., the epidermis of branchlets exfoliating with fall of lvs, the new foliage crowded at tip of homotinous branchlets on a framework of naked cinnamon-brown older ones, the axis of young stems, lvs and peduncles strigose with fine tapering appressed-ascending setae to ±1—1.5 mm commonly mixed with minute villi or subsessile glands or both, the tiny crowded lfts either glabrous or puberulent above, commonly puberulent beneath, finely setulose-ciliolate, the inflorescence a compact, scarcely or shortly exserted pseudoraceme of conelike globose or squatly ovoid-ellipsoid capitula, the pods axillary. Stipules caducous (little known), lance- or ovate-acuminate ±4-6 x 1.5-3 mm, internally glabrous castaneous. Leaf-stalks 6-16 cm, the petiole together with or reduced to the obese pulvinus 2.5-6 mm, the longer interpinnal segments 2-6(-6.5) mm, the ventral groove concealed by setae but continuous between pinna-pairs (spicules 0); pinnae (15-) 17-28-jug., strongly decrescent proximally and a little so distally, the rachis of longer ones 23—43 mm, the longer interfoliolar segments 0.4-0.9 mm; lfts of longer pinnae 30-47-jug., the first pair directly next to pulvinus (paraphyllidia 0), all in outline narrowly oblong, linear, or (when very short) oblong-elliptic, obtuse or apiculate, smooth veinless above, weakly 1-2-nerved beneath. Peduncles 2.5-5 cm; capitula without filaments 10-12 mm diam.; bracts oblanceolate mostly 5-6.5 x 0.9-1.5 mm, the lowest sometimes shorter, all setulose and usually glandular dorsally; flowers 4-merous 8-androus, some lower ones staminate; calyx 0.6-1 mm, the undulately truncate rim with few plain or gland-tipped setulae to 0.3-0.5 mm; corolla 3-5.5 mm, the narrowly funnelform tube glabrous, the ovate lobes 1-1.3 mm, 1-nerved, densely minutely setulose externally; filaments pink fading whitish, monadelphous through ± 1 mm, exserted to 9-15 mm. Pods ±2-4 per capitulum, sessile, when well fertilized broadly linear in profile 45-60 x 11-13 mm, the replum 1-2 mm wide, the low-convex valves shallowly depressed between the 8-11 seeds, the livid exocarp 0.05-0.1 mm and the papery-crustaceous endocarp 0.1-0.2 mm thick in section, the replum and valves alike densely strigose-hispid with forwardly subappressed-ascending setae to 1-1.5 mm mixed with shorter gland-tipped setulae, the ripe valves separating entire from all but very base of replum, recurved from apex to release the seeds, these not seen.
Distribution and Ecology - About sandstone outcrops in campo, ±1200-1250 m, endemic to the heights of Sa. dos Cristais within a radius of ± 10 km of Cristalina, near 16°45'S in s.-e. Goiás.-Fl. III-IV.
Very closely related to M. densa, M. heringeri, and M. setosissima, which see for comment.
Distribution:Brazil South America
| Goiás Brazil South America