Chamaecrista venulosa

Precociously flowering herbs becoming suffruticose, variable in habit, the primary stem erect, its branches often diffuse or humifuse, at anthesis 1.5-15 dm, except for the glabrous faces of the serrulately ciliolate lfts pilosulous with shorter incurved and longer, straighter spreading hairs to 0.7—1.3(—12.6) mm, the long, often yellowish hairs sometimes almost or quite lacking below the pedicels or calyx, the stems equally but usually not densely leafy, the straight internodes 8-20 mm, as long or longer than stipules.

Stipules erect, lance-acuminate from an obscurely cordate base, 5-13 (-15) x 0.7-1.5 mm, submembranous, from base 5-9-nerved, glabrate facially, ciliolate, feebly persistent.

Lvs ascending, straight or outwardly arcuate, 1.5—5(—6) cm, shortly petiolate, the expanded blade ovate in outline; lf-stalk 1-3.5(-4.2) cm, narrowly margined ventrally, the petiole 2-4(-5) mm, the rachis slightly dilated under the pulvinules; petiolar gland (sometimes 2) near middle of petiole or immediately above pulvinus, round or nearly so, 0.35-0.7 mm diam, squatly short-stalked or subsessile, 0.3-0.4(-0.5) mm tall; lfts 4-8 pairs, slightly diminished upward, obliquely oblong, lance-oblong, or oblong-elliptic, (5—)7— 16(—21) x 1.5-4(-5.2) mm, at asymmetric base shallowly cordate, at abruptly acuminulate apex contracted into a cusp 0.4-0.8 mm, from base on both faces prominently 5-9-nerved, the excentric, penninerved midrib displaced to ± the distal 1/3 of blade, straight or slightly incurved distally, finely penninerved.

Peduncles exactly axillary, ±1 mm, concealed by stipules, 1-fld; bracts and bracteoles lance- or narrowly ovate-acuminate, (2-)2.5-5 mm; pedicels widely ascending, 2-3.3 cm; buds ovoid-acuminate, pilose; sepals membranous, greenish where exposed in bud but with wide petaloid margins, ovate- or lance-acuminate, 7.5-10.5 x 2.4-4.4 mm; petals yellow, the 4 similar obovate-cuneate, 9-13 mm, the strongly oblique landing-petal 12-14.5 mm; stamens 10, the anthers yellow 4.7-9 mm, the 3 longer ones 7-9 mm, all minutely puberulent along the sutures; ovary densely white-pilose; style glabrous linear 4.3-7 mm; ovules 8-12.

Pod linear-oblong, (2.5-)3-4 x 0.6-0.75(-0.9) cm, the green, softly pilose valves becoming dark brown or blackish; seeds 3.5-4 mm long, the testa black, dull, lineolate-pitted.—Collections: 18.

Open grassy, sometimes disturbed sites in cerrado, in seasonally inundated campo (brejo), and in quartz sand along streams and about rock outcrops, 1100-1320 m, along the crest and higher e. and w. slopes of Sa. do Espinhaço from Belo Horizonte n. to Sa. de Curumataí in lat. 17°50'-20°S; disjunct, on carrasco at 1700 m, near the s. end of Chapada Diamantina in s. Bahia (Pico de Almas) near 13°35'S; and (if data correct) found once by Martius on the Sao Francisco-Paraná divide in the n.-w. comer of Minas Gerais near lat. 15°S, the occurrence w. of Rio São Francisco requiring confirmation.—Fl. I-V(?VIII).

Although from a locality remote from the main range of Ch. venulosa in Minas Gerais, the cited isotypus of Cassia luetzelburgii matches closely some collections from the Diamantina region. Harms compared C. luetzelburgii with the small-flowered Ch. serpens and Ch. trichopoda, from which it is, of course, amply distinct.