Monographs Details: Mimosa flavocaesia 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 cyclophylla Taub., Mimosa rigida Benth.
Description:Species Description - Functionally herbaceous, macrophyllidious subshrubs from xylopodium, including the simply pseudoracemose inflorescence 3-7 dm tall, the 1-few incurved-ascending or erect stems bearing at each of (2-)3-6 nodes between rootstock and middle a narrowly ascending lf, the stems, lf-stks and axes of inflorescence all hispid (or the latter strigose) with widely to narrowly ascending tapering yellow setae to 2-6 mm, the firm glaucescent lfts grossly corneous-marginate and serrately ascending-spinulose-ciliate, all facially glabrous or the 1-2 proximal pairs of some lvs thinly strigose-setose dorsally. Stipules associated with lvs firm, lanceolate or linear-oblong 5-13 x 0.8-3 mm, obscurely nerved externally, persistent, those subtending peduncles narrower and often less enduring. Leaf-stalks near base of stem 3-8 cm, of some distal lvs only 0.5-3 cm, all at middle 1.3-1.8 mm diam., bluntly 3-ribbed, broadly shallowly sulcate ventrally; pinnae 1-jug., the axis of each (5-)7-14 cm, the first pair of lfts (1.5—)3—8 mm distant from pulvinus, its anterior lfts much smaller than the posterior one, the longer interfoliolar segments ± 1-2.5 cm; paraphyllidia minute conic, or obsolete; lfts (5—)6—1 l(-13)-jug., subdimidiately or very obliquely ovate obtuse, at base broadly semicordate proximally, the longer ones 19-27 x 1016 mm, 1.6-2.2 times as long as wide, all palmately (5-)6-9-nerved from broad short nigrescent pulvinule, the almost straight excentric costa dividing blade ±1:2, the primary and weak secondary venation immersed on upper face, sharply prominulous beneath, the stout yellowish corneous margin with a single file of subappressed tapering setae free for 1.5-2.5 mm. Peduncles solitary (2-)2.5-6 cm; capitula globose, without filaments 10-11 mm diam., prior to anthesis moriform but the minutely puberulent or glabrous fl-buds only shortly emergent from bracts, these linear-oblanceolate 2.2-3.5 x 0.6-0.8 mm, glabrous dorsally, near apex ciliate on each margin with ±3-5 setae to 1-2 mm; flowers 4-merous 4-androus, some or many in a capitulum functionally staminate; calyx paleaceous 2.5-3.8 mm, cleft to below middle into 4 irregularly lacerate lobes; corolla narrowly funnel-form 3.8—4.8 mm, the narrowly cymbiform subcorneous, dorsally keeled lobes 1.2-1.5 x 0.65-1 mm; filaments pink, connate around pistil into a tubular sheath 2-3.5 mm, exserted 6-8 mm, thickened subapically. Pods to 3(-?) per capitulum, seen only half-formed but at that stage closely resembling those of M. cyclophylla, the valves densely strigose with forwardly appressed, basally dilated, pale yellowish setae; ovules 4-5.

Distribution and Ecology - On stony or sandy campo subject to fire in the dry season, 950-1100 m, known with certainty only from the s. end of Chapada dos Veadeiros within a 20 km radius of Alto Paraíso, near 14°30'S in e.-centr. Goiás, Brazil, the single record from Sa. dos Pireneus, ±250 km to s.-w. of Veadeiros (Glaziou 21074, G, P) requiring confirmation. -Fl. XI-III(-?)

Discussion:

Mimosa flavocaesia resembles M. cyclophylla in growth-form, in thick-textured corneously marginate, relatively ample leaflets, and in paleaceous calyx and monadelphous stamens, and is clearly a close relative. It differs, however, in lesser stature, in stems foliate about to middle and not only radically, and particularly in the obliquely or dimidiately ovate (not suborbicular), rather smaller leaflets ciliate with emergent cilia. The visually striking contrast between yellowish-setose margin and glaucescent faces of the leaflets suggested the epithet.

Distribution:Brazil South America| Goiás Brazil South America|