Monographs Details: Mimosa pseudofoliolosa 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.
Family:Mimosaceae
Synonyms:Mimosa foliolosa Benth. var. foliolosa
Description:Species Description - Of unrecorded stature but apparently a functionally herbaceous subshrub from xylopodium, the prostrate unarmed stems freely branched distally and passing into a panicle of efoliate pseudoracemes elevated 1-3 dm above developed lvs, the stems and all axes of lvs and inflorescence densely pilose and viscid-villosulous with fine erect plain yellowish setae to 2-2.5 mm, minute pallid incurved hairs, and filiform erect gland-tipped setulae to 0.8-1.2 mm, the minute concolorous, when dry brownish sublustrous lfts ciliolate with plain and gland-tipped setulae but facially glabrous, the small capitula subglobose. Stipules firm reflexed lanceolate ±4-6 x 1 mm, pubescent dorsally like adjacent stem, persistent. Leaf-stalks of major cauline lvs 4-7 cm, the petiole and livid pulvinus together 1.5-3 mm, the interpinnal segments 2.5-4 mm, the narrow ventral groove bridged between pinna-pairs but spicules 0; pinnae 12-17-jug., of subequal length, the rachis (5-)7-10 mm, the interfoliolar segments ±0.5 mm; lfts 14-18-jug., the first and last pairs smaller but the rest subequilong, the first pair 0.2-0.3 mm distant from pulvinus (paraphyllidia 0), all oblong obtuse from semicordate base, the largest 1.2-1.7 x 0.4-0.7 mm, ±2.7 times as long as wide, all indistinctly costate dorsally, otherwise veinless. Peduncles solitary and geminate 1.7-2.3 cm; capitula including interfloral bracts but without filaments 4-5 mm diam., the linear-elliptic bracts 2-2.5 x 0.3-0.4 mm, distally glandular-puberulent, prior to anthesis projecting beyond the obovoid fl-buds; flowers 4-merous 8-androus, the lower ones staminate; calyx 0.5-0.8 mm, glabrous externally, the obscurely denticulate rim either glabrous or with a few minute cilia; corolla turbinate 2.5-3.1 mm, the almost plane nerveless lobes 1.2 x 1 mm, thinly puberulent externally with plain and gland-tipped setulae; filaments pink, shortly monadelphous around base of glabrous ovary, exserted 4.5-6.5 mm; pod unknown.

Distribution and Ecology - On gravelly soil in cerrado, near 1000 m, known only from the type-locality on the headwaters of rib. Samambaia, a source-tributary of rio S. Marcos, at 16°10'S, 47°35'W in s.-e. Goiás, Brazil.— Fl. I-II(-?).

Discussion:

This ambiguous mimosa resembles M. foliolosa var. foliolosa in short pinnae and minute leaflets, but differs in prostrate, paniculately branched stems, shorter leaf-stalks, and very small capitula. In habit it recalls M. gracilis, but its stipules suggest (in absence of the pod, which would be decisive) much closer affinity to M. prorepens, from which it differs in pronounced viscid-villosulous indumentum of stem, leaf and inflorescence, in subsessile leaves, in pinnae 2-3times shorter, leaflets less than half as many (14-18-, not 26-50-jug.) and minute leaflets (less than 2, not 2.5-5.5 mm long).

Distribution:Brazil South America| Goiás Brazil South America|