Chamaecrista ramosa var. erythrocalyx

Erect or diffuse, freely branching subshrubs, at anthesis (1.5-)2.5-10 dm, the olivaceous or exceptionally glaucescent foliage either glabrous or finely pilosulous, the purplish-castaneous annotinous branchlets naked; stipules ovate-cordate to broadly lanceolate (1.5-) 1.8-8 x (1-) 1.3-3 mm, usually shorter than the internode, deciduous with or before the lf; lf-stalks of larger lvs (1.5-)2-4.5(-5) mm, the petiole 1.5-3.5(-4), the rachis 0.2-1 mm; gland urceolate (0.2-)0.3-0.8(-0.9) mm diam, sessile or shortly stipitate, if the latter then in profile obconic to tack-, peg- or shortly trumpet-shaped, 0.3-0.8 mm long, from 0.7 mm shorter to 0.25 mm longer than diam of head; lfts linear-oblanceolate to narrowly obovate obtuse, obtuse-mucronulate, rarely acute, the larger (distal) pair ±¼-½ longer than the proximal, up to (6—)7—15(—19) x 1.5—4.5(-6) mm, (3—)3.5—6(—9) times longer than wide; pedicels (13—) 15—30(—35) mm, glabrous, unilaterally puberulent, or puberulent all around; long sepal (8—)10—16 mm; longest petal (10—)11—16(—17) mm, either a little longer or shorter than the longest sepal; pod 22-48 x 5.5-7.5(-8.5) mm, finely strigulose or glabrous; ovules 10-19.—Fig. 53.

High campo sujo, stony or sandy meadows, rocky stream-banks and about outcrops, 950-1400, on Chapada dos Veadeiros up to 1750 m, locally abundant along the crest of Sa. do Espinhaço from Grão Mogol s. to Sa. do Cipó (± 16°30'- 19°30'S) in centr. Minas Gerais, and on the caprock of Chapada dos Veadeiros and Sa. dos Cristais in e.-centr. and s.-e. Goiás.—Fl. (X-)XI-III(-V).

The well known phase of var. erythrocalyx corresponding to Cassia langsdorfii var. tenuis, which occurs on Serra dos Cristais both in common pilosulous and rarer glabrate forms, is a slender erect shrublet some 5-15 dm tall with wiry naked trunks and gracefully drooping branchlets clothed in neat glaucescent foliage. The stipules are ovate-cordate and much shorter than the internodes, and the petiolar glands are shortly stipitate, trumpet-shaped in profile. An almost exactly similar except slightly larger-flowered race (Irwin et al. 23326) occurs on Sa. Grão Mogol, far distant in northern Minas Gerais, and this in turn very closely resembles the type-collection of C. gracilis var. erythrocalyx, obtained by Martius in the same general region. The latter, mentioned inconclusively in the last revision (Irwin, 1964, p. 68) as a probable synonym of var. tenuis, is now known to us through the holotypus and imposes an earlier varietal epithet.

The populations of var. erythrocalyx on the crest of Chapada dos Veadeiros like most of those known from Sa. do Espinhaço southward from Diamantina differ in longer or at least proportionately longer, lanceolate stipules often coinciding with a more bushy growth-form and sometimes (but not always) with sessile glands. The immediate environs of Diamantina have yielded in addition two visually arresting forms, one (Mexia 5828; Irwin 2474; Irwin et al. 22629) notable for relatively ample foliage, lanceolate stipules and stud-shaped glands, closely simulating in general aspect small-leaved forms (or late-season specimens) of Ch. desvauxii; the other (Glaziou 19091; Irwin et al. 21964, 27677) remarkable for tiny ovate stipules, minute foliage and relatively short and broad sepals. The one character common to all these is the early loss of the stipules and in consequence a framework of naked wiry atrocastaneous old stems supporting the leafy annotinous branchlets. This, too, is the one feature useful in practice to distinguish var. erythrocalyx from sympatric var. parvifoliola and its otherwise virtually identical but more southern form described as C. chartacea var. tenuicaulis.