Cassia ciliolata

  • Title

    Cassia ciliolata

  • Author(s)

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Cassia ciliolata Benth.

  • Description

    78.  Cassia ciliolata Bentham in Martius, Fl. Bras. 15 (2): 146. 1870, sens, restr. sub var. ciliolata infra.

    Diminutive undershrubs with few slender castaneous simple or widely few-forked stems 1-3 dm ascending from a knotty xylopodium, except for the often glabrate faces of the small roundish always setose-ciliolate lfts in all parts villosulous and viscid-hispidulous with yellowish setules up to 0.4-1.7 mm, the concolorous foliage glaucescent in age, the very slender terminal simply racemose inflorescence not or shortly exserted.

    Stipules erect, subulate, rather firm, 1-4 mm persistent.

    Lvs ascending, 3-8 cm, petioled; pulvinus ± bulbous-dilated, livid, when dry wrinkled, 0.6-1 mm; petioles 5-18 mm, at middle 0.4-0.6 mm diam, openly shallow-grooved ventrally; rachis 2-7 cm, sometimes abruptly nodular-dilated under each pair of lfts; lfts 4-21 pairs, divaricate from or tilted forward from the rachis, turned adaxial margin to the meridian, on livid pulvinule 0.2-1 mm, in outline suborbicular or broadly ovate, obtuse or broadly deltate- acute, 2-14 x 2-9 mm, at oblique base cordate on both or at least the distal side, the margins plane, entire or obscurely crenulate, glandular-setulose, the adult blades stiffly chartaceous, on both sides olivaceous or pinkish-brown, when young densely papillate, when adult glaucescent, the midrib with a single or from below middle of blade 1-2 pairs of secondary veins prominulous beneath, the venation above immersed or almost so, the tertiary venulation imperceptible.

    Inflorescence terminal, simply racemose, 5-30-fld, the lowest 1—3 fls sometimes leafy-bracteate, the axis becoming 1.5-9 cm, the several simultaneously expanded fls standing somewhat below the unopened buds; bracts subulate castaneous 1.5-2.7 mm, persistent; pedicels subfiliform ascending (8-) 10-18 mm, bracteolate 1-3 mm below calyx; bracteoles like bracts, slightly smaller, tardily deciduous; buds subglobose, obtuse, microscopically villosulous and thinly yellow-setulose; sepals widely ascending, elliptic-oblanceolate to obovate, obtuse, 5.5-6.7 x 2.2-3.4 mm; petals yellow, the four plane ones of almost equal length but different widths, broadly to narrowly obovate-cuneate, the longest 9-10 x 6.5-8 mm, the fifth almost as long but falcately half-ovate and coiled over the androecium; ovary setulose; ovules 4-6.

    Pod (not seen fully ripe) 2.5-3 x ±6.5 mm, minutely pilosulous and thinly yellow-setulose.

    A diminutive undershrub with slender stems rising annually, mostly less than a foot high, from a knoblike xylopodium, C. ciliolata has been confused with its neighbor and close relative C. multipennis. The latter is a true shrub with persisting aerial trunks that can reach the proportions of a treelet, and is further distinguished by subsessile leaves, leaflets usually not pectinately ciliate, acute or apiculate flower-buds, longer muticous anthers, and a characteristic broad and short, few-seeded pod. In its immediate group the distantly allopatric C. nanodes alone has similar dwarf growth-habit, but combined with buds and anther-connective almost of C. multipennis.

    In its rather compact range around the upper forks of Rio Sao Francisco and southern Serra do Espinhaço, C. ciliolata has become subject to some minor but taxonomically significant varietal differentiation. Strictly typical var. ciliolata, known certainly only from the west side of the valley, probably not above 1000 m, is notable for the modified leafstalk, dilated at insertion of the 4-10 pairs of leaflets into a conspicuous pallid hemispherical nodule which supports a very short and inconspicuous pulvinule. At similar altitudes on Serra do Cabral east of the Sao Francisco, the species is represented by var. caprina, differing chiefly in the almost unmodified leafstalk and more numerous (9-21) pairs of leaflets. Finally in southern Serra do Espinhaço, at about 1500 m and extending eastward across the Sao Francisco-Doce divide to Itabira, the species is represented by var. pulchella, like var. ciliolata in number of leaflets, like var. caprina in the rachis, but different from both in the hispidly yellow-setose stems and more ample, obviously petiolulate rather than subsessile leaflets.

    Key to varieties of C. ciliolata

    1. Lfts 4-10 pairs, glabrous on both faces or (when young) rarely puberulent.

    2. Rachis strongly dilated under each pair of lfts, the pallid, hemispherical dilation nearly as tall as the length of the very short pulvinule (0.2-0.4 mm); stems hispidulous with setules up to ± 0.5 mm.

    a. var. ciliolata

    2. Rachis not dilated under the lfts, the pulvinule much longer, 0.6-1 mm; stems hispid with setae up to 1-1.7 mm.

    b. var. pulchella

    1. Lfts 9-21 pairs, thinly pilosulous on both faces. Rachis not dilated, but pulvinules short and pubescence setular as in var. ciliolata. 

    c. var. caprina