Monographs Details: Mimosa capito 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 oedoclada Barneby, Mimosa manidea Barneby
Description:Species Description - Pachycaul treelets 2-3 m with trunk attaining ± 1 dm diam. and symmetrically branched crown of stout defoliate branches bearing a rosette of amply microphyllidious lvs, the annotinous branchlets ± 1-1.5 cm diam., transversely ridged by lf- and stipule-scars but the bark not exfoliating, the lf- and inflorescence-axes densely hispid with flagelliform setae to 3-4 mm long and 0.2-0.3 mm diam. at bulbous base, below the floral bracts eglandular, the subcoriaceous lfts concolorous, when dry brown-olivaceous lustrous glabrous on both faces, setose-ciliate, the inflorescence of globose capitula pseudocorym- bosely crowded into a dense cluster nestled in the terminal lf-rosette. Stipules coriaceous triangular-lanceolate ±10 x 4 mm, densely setose dorsally, glabrous within, early deciduous. Leaf stalks 12-22 cm, the petiole including (or reduced to) the obese hard pulvinus 5-15 x 3-4 mm, the longer interpinnal segments 7-11 mm, the narrow ventral sulcus bridged between pinna-pairs but spicules 0; pinnae 14-22-jug., strongly decrescent proximally but scarcely so distally, the rachis of longer ones 6-8 cm, the longer interfoliolar segments 1.2-1.8 mm; lfts of longer pinnae 33-55-jug., subequilong except at very ends of rachis, the first pair close to pulvinus (paraphyllidia 0), the blades oblong from bluntly auriculate base, obtuse or subapiculate, the longer ones 5.5-8 x 1.7-2.5 mm, 3.1-3.5 times as long as wide, all faintly or subobsoletely 3-4- nerved from pulvinule, the slightly excentric midrib a little porrect beyond mid-blade. Peduncles at anthesis 1.5-2.5 cm, subtended by an incipiently expanding hysteranthous lf; capitula without filaments 15-17 mm diam., prior to anthesis conelike and densely setose overall; bracts linear-oblanceolate 5.5-7.5 x 0.7-1 mm, barbate dorsally with plain and a few gland-tipped setae; flowers 4-merous 8-androus, all but a few lower ones bisexual; calyx membranous campanulate 0.6-0.8 mm, its subtruncate orifice ciliolate with a few plain and gland-tipped setulae 0.2-0.3 mm; corolla glabrous overall, narrowly vase-shaped 6-7 mm, the ovate-triangular subacute 1-nerved lobes 1.2-1.5 mm; filaments lilac-pink, united below ovary into a stemonozone ±0.7 mm, exserted 10-15 mm; ovary setose after fertilization; pod unknown.
Distribution and Ecology - Colonial on rocky ridges and hilltops in campo rupestre, 1000-1200 m, known only from the heights of Chapada dos Veadeiros in the vicinity of Alto Paraíso, ± 14°-14°10'S in e.-centr. Goiás, Brazil.-Fl. X-XII.
Mimosa capito differs from the several compatriot pachycaul arborescent species in the dense inflorescence of shortly pedunculate capitula nestling in the terminal rosettes of ample leaves and in the completely hairless corollas. It has larger leaves than either M. oedoclada or M. manidea and differs from the first of these in nonexfoliating bark of annotinous branchlets and from the second by early deciduous stipules. Its close neighbors M. densa and M. laniceps have exfoliating bark combined with smaller leaves, fewer leaflets, shorter peduncles, smaller flowers, or some of these characters combined. The foliage is completely eglandular, but there are a few capitate excretory setulae hidden among the longer plane setae of the floral bracts. In this respect the species recalls M. claussenii, in practice easily distinguished by an extended inflorescence and setulose corolla-lobes.
Distribution:Brazil South America
| Goiás Brazil South America