Cassia juruenensis

  • Title

    Cassia juruenensis

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Cassia juruenensis Hoehne

  • Description

    150.  Cassia juruenensis Hoehne in Commissao Linh. Telegr. Matto Grosso, Hist. Nat., Bot. 12 (Contr. Conheç. Legum. Rondonia): 13, t. 185, fig. II. 1922. — "No. 1841, Hoehne, Juruena, Rondonia, Matto-Grosso, em Maio de 1909." — Holotypus, R (no. 27420)! = NY Neg. 2882.

    Cassia desertorum sensu Bentham in Martius, Fl. Bras. 15 (2): 153, p. p. (Gardner 2546), exclus. typ.

    Erect bushy shrubs 1-2 m with few slender blackish, finally furrowed and striped but not peeling trunks paniculately branching distally into a rounded crown of foliage, except for the often glabrous or glabrescent upper lf-surface densely softly pilosulous or tomentellous with fine, forwardly incurved, curly, or sometimes largely spreading hairs up to 0.2-0.5 (-0.6) mm, below the terminal, simple or paniculate, finely viscid-setulose, exserted inflorescence not or scarcely glandular, the rather thick-textured lfts moderately bicolored, finely wrinkled above when dry.

    Stipules erect, subulate-setiform, 0.9-2.7 mm, persistent.

    Lvs ascending (1.5-)2.5-6.5(-7) cm, stoutly short-petioled; pulvinus ellipsoid, discolored, when dry wrinkled, 2-3 mm; petiole (5-)7-17(-20) mm, at middle (0.5-)0.65-1 mm diam, coarsely winged, narrowly sulcate, the wings dilated under the pulvinules; lfts 2 pairs, ascending from rachis, turned half face to face on dilated pulvinule mostly 0.5-1.4, rarely 1.3-2.3 mm, in outline obovate obtuse or commonly emarginate, mucronate or mucronulate, (0.7-) 1-3.6 x (0.5-)0.7-2.4 cm, at base cordate on proximal side, subcordate to cuneate on distal one, the ciliolate margins usually at least incipiently revolute, the blades chartaceous, above brownish-olivaceous dull or (young) glutinously sublustrous, glabrous or rarely puberulent, beneath always densely pilosulous and paler, the stout, tapering, often reddish midrib depressed above, cariniform beneath, the 4-7(-8) pairs of very slender secondary veins either finely prominulous on both faces or only beneath, the tertiary venulation imperceptible.

    Racemes subsessile, ascending-erect, either terminal to stiffly ascending branchlets or by suppression of some lvs forming a terminal distally leafless panicle, the individual racemes ± 5-30(-35)-fld becoming 2-14(-18) cm, the one expanded flower displayed near level of the corymbose unopened buds; bracts submembranous triangular-subulate 0.8-1.3 mm, becoming dry, brown, tardily deciduous; pedicels stiffly ascending straight, or widely spreading and geniculate under the pod, 1-1.5 cm, bracteolate 2-10 mm below calyx; bracteoles 'ike bracts, slightly smaller; buds ovoid obtuse, appressed- or spreading-pilosulous and minutely glandular-setulose; sepals yellow-brownish or reddish-tinged, elliptic or broadly oblance-elliptic, obtuse, 9.5-13 x 3.8-5.2 mm; petals yellow, loosely ascending, the four plane ones of different sizes, broadly oblanceolate to obovate-cuneate, 14-19 x 6.5-10.5 mm, two of them smaller and broader, the dimidiate coiled one longest, 16-21 mm; ovary densely velutinous and minutely viscous-setulose; ovules 5-8.

    Pod linear-oblong, ±3.5-4.5 x 0.55-0.7 cm, the reddish valves thinly villosulous and viscid-setulose; seeds (few seen) 4.6-5.2 x 3.2-3.7, compressed-pyriform, the testa brown turning black, lustrous, lineolate. — Collections: 9.

    Cerrado, cerradao, and disturbed woodland (capoeira), 200-600 m, sometimes on sandstone outcrops, scattered around and near the n. margins of the Brazilian Planalto in n. Mato Grosso (Chapada dos Parecis; Serra do Roncador), n. Goias (Serra dos Cordilheiros), e.-centr. Maranhao (Caxias) and n.-w. Bahia (n. Espigao Mestre). — Fl- VI —IX.

    A species well marked among the Absoideae by the soft gray vesture of stems, leaf-stalks, and leaflets which fully masks or commonly replaces any setular pubescence below the always viscid inflorescence, and by the coarsely winged and relatively short petiole which is dilated immediately below the two pairs of usually very short pulvinules.