Monographs Details: Cassia scabra J.E.Pohl ex Benth.
Authors:Howard S. Irwin, Rupert C. Barneby
Authority: Irwin, Howard S. & Barneby, Rupert C. 1978. Monographic studies in Cassia (Leguminosae, Caesalpinioideae). III. Sections Absus and Grimaldia. Mem. New York Bot. Gard. 30: 1-300.
Family:Caesalpiniaceae
Description:Species Description - Subshrub with 1-5 mostly simple, coarsely and amply few-lvd stems erect or ascending from a knotty xylopodium and deeply penetrating root-system, densely glandular-villosulous and -setose or -setulose almost throughout, the stems, lf-stalks and axes of the terminal, complexly paniculate inflorescence hispid with erect glabrous glutinous setae up to 1-4.5 mm, the foliage bicolored, above glutinously lustrous and thinly scabrid-setulose, beneath paler, intricately reticulate and softly gray-pilosulous and setulose or the villi rarely reduced to papilli and then merely setulose. Stipules stiffly erect or incurved-ascending, linear-lanceolate, 3-8.5(-11) mm, prominently ribbed dcrsally, persistent. Lvs of each stem 5-12, increasing in size upward, the small lower ones mostly deciduous by anthesis, all rigidly ascending, stoutly and shortly petioled, (4.5-)7-18 cm; pulvinus obscure, scarcely differentiated; petiole stiffly ascending at a narrow angle to the stem (3-)5-20(-26) mm, 1.4-2 mm diam, widely open-sulcate ventrally, abruptly dilated at apex; rachis 0, reduced to a stipuliform appendage arising between the two lfts; lfts 1 pair, stiffly erect from apex of petiole, pointing toward the meridian, turned half face to face on ovoid or drum-shaped, when dry wrinkled pulvinule 1.4-2 mm, in outline obovate or rhombic-obovate to oblanceolate or elliptic-oblanceolate, obtuse and shallowly emarginate to acute or shortly acuminate, always mucronulate by the excurrent midrib, (3.5-)5-16.5 x (1.5-)2.5-7 cm, at base asymmetrically cuneate-attenuate, the margin entire, revolute, the blades firmly chartaceous or subcoriaceous, above olivaceous or brownish, lustrous, glutinous, thinly scabrid-setulose (-setose) along the veins and venules, beneath pallid, similarly setulose and also commonly villosulous with fine hairs divergent from and erect between the venules, the midrib and (7-)9-16 pairs of secondary veins above pallid-yellowish, superficial to slightly depressed or bluntly prominulous, beneath commonly brownish, always sharply elevated and riblike, the connecting tertiary and reticulate venulation above obscure, beneath sharply prominent, forming a mesh of sunken areoles < 1 mm diam. Inflorescence a terminal, closely branching, subcorymbose, round- or flat-topped leafless or basally leafy-bracteate panicle of racemes 8-18 cm, (5-)6-12 cm diam, elevated to or shortly above the uppermost foliage, the axes of individual racemes mostly few- but densely fid, becoming 3-9(-11) cm, the 1-2 flowers simultaneously expanded raised ± to level of succeeding buds; bracts lanceolate, 2-5.5 mm long, persistent; pedicels 1.6-2.7(-3.5) cm, bracteolate 2-7 mm below calyx; bracteoles resembling bracts but shorter, subulate or lanceolate, 1-2.5 mm, persistent; buds plumply ovoid, obscurely or shortly apiculate by the incurved tip of exterior sepal, thinly setose or setulose and usually also minutely villosulous, sepals reddish- green, the inner with petaloid margin, elliptic or elliptic-oblanceolate, the outer acute or subacute, the inner obtuse, 9.5-14 x 3-4.5 mm; petals yellow, four ascending at ±45 from vertical, unequally obovate-cuneate, up to 12.5-16 x 6-8.5 mm, the fifth obliquely dimidiate, coiled; ovary densely setose; ovules 6-9. Pod linear-oblong, straight or slightly curved downward, 3.5-6.5 x (0.6-)0.7-1 cm, the valves green turning reddish-brown, viscid-villosulous and densely hispid with erect purplish setae; seeds (few seen) compressed-obovoid, purplish-black, moderately lustrous, finely crackled transversely, imperceptibly lineolate. — Collections: 17.

Distribution and Ecology - Open stony campo and steep rocky slopes above the gallery forest, 700-1200 m, highly localized but locally abundant, highlands of s.-e. Goias, from the sources of Rios Maranhao and Tocantins s. over the watershed to the upper forks of the Rio Paranaiba, w. to Serra dos Pireneus, e. to Serras Geral do Parana and do rio Preto on the Minas border, s., perhaps interruptedly, in the Contraforte Central to Catalao. — Fl. (X) XII —III. "Habitat inter Montes Claros et Ouro fino, prov. Goyaz: Pohl."

Discussion:

A species of striking aspect, notable for the short stems clad in a few coarse upswept bifoliolate leaves of stiffly chartaceous texture and reticulate beneath, and for the closely ramified terminal panicle of racemes, when fresh sparkling like a sundew with innumerable drops of exudate poised at the tip of reddish setae. It appears related to C. setosa, C. ochrosperma, and C. campicola, all more or less sympatric, and all different in their bijugate leaflets. In the characters of low stature, setose pod, and often elongate leaflets, C. scabra resembles C. campicola more closely than the two others, but has erect, not diffusely trailing stems.

In the material studied there are three instances of a notable variant in which the villosulous vesture of the foliage is reduced to pallid papillae while the armament of setae remains unchanged. This variant is analogous to C. setosa var. subsetosa, but is known to occur in the same population with normal C. scabra (Irwin & at 12977; Glaziou 21003) as well as in apparently pure stands (Irwin & at 31816). It thus seems best evaluated as taxonomically insignificant.

Distribution:Minas Gerais Brazil South America| Goiás Brazil South America| Paraná Brazil South America| Brazil South America|

Narratives:Cassia scabra