Senna uniflora

  • Title

    Senna uniflora

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Senna uniflora (Mill.) H.S.Irwin & Barneby

  • Description

    71.  Senna uniflora (P. Miller) Irwin & Barneby, comb. nov. Cassia uniflora P. Miller, Gard. Diet. ed. 8, Cassia no. 5. 1768.—"Senna spuria herbacea orobi Pannonici foliis . . . Houston MSS . . . Sent me from Cam- peachy by the late Dr. Houston."—Holotypus, labelled "Campeachy, Houston, 1730," ticketed by Houston and by Miller, BM (plant second from left only)! = BH Neg. 5165 = NY Neg. 113.—C. sericea Swartz, Prod. 66. 1788 & Fl. Ind. Occ. 2(1): 724. 1798, nom. substit. illegit. C. monantha DeCandolle, Prod. 2: 506. 1825, nom. illegit. Sericeocassia uniflora (P. Miller) Britton ex Britton & Rose, N. Amer. Fl. 23(4): 246. 1930.

    Cassia ornithopoides Lamarck, Diet. 1: 644. 1785.—". . . croit dans l’Amerique meridionale . . . communiquee par M. Thouin."—The only spm in P-LAM is a lf acquired from Aublet, possibly clastotypic. Neotypus, labelled "C. ornithopoides, " collected in Santo Domingo by Poiteau, FI (hb. Webb, via Desfont.)!

    Cassia sensitiva Jacquin, Collectanea 362. 1789 & Ic. PI. Rar. 3: t. 459. ±1790.—"Jamaica patria est."—Holotypus, grown at Schonbrunn, W. (hb. Jacqu.)!

    Cassia ciliata Hoffmannsegg, Verzeichniss Pflanzenkult. 208. 1824.—"H. in Cuba."—Described from cultivated plants, thought to differ from a description of C. sericea by Link, but certainly C. uniflora e descr.—C. sericea (?) var. ß [C.] ciliata (Hoffmannsegg) Vogel, Syn. Gen. Cass. 24. 1837.

    Emelista mucronulosa Pittier, Jour. Wash. Acad. Sci. 19: 176. 1929.—"Lara: vicinity of Bar- quisimeto; flowers and fruits July, 1925 (J. Saer d’Heguert 282 . . .)."—Holotypus, US!

    Cassia sericea sensu Bentham, 1870, p. 116, t. 35, fig. 1; 1871, p. 536, the illegitimate epithet preferred because more appropriate.

    Coarse malodorous monocarpic herbs from shallow blackish root, usually stiffly erect and simple or paniculately few-branched distally, rarely branched from base, diminutive when starved or crowded but commonly at anthesis 2-12, rarely 20 dm tall, variably pubescent with extremely fine short whitish villi mixed with stouter, forwardly subappressed or some spreading rufescent setae up to (0.8-)l-2 mm, only the lower stem and some early lvs glabrate, the subconcolorous lfts always setose dorsally (especially along veins) and setose-ciliate, on the upper face thinly or densely (even subvelutinously) villosulous, the shortly pedunculate racemes of few small short-pedicelled fls axillary to and shorter than all major lvs.

    Stipules erect or subfalcately erect, narrowly linear-attenuate or -caudate (5-)7-24 x 0.3-1.2 mm, the thinly herbaceous blades asymmetrically 1-nerved, deciduous before the lf.

    Lvs (disregarding those of late depauperate branchlets) 5-16 cm; petiole including moderately swollen pulvinus 1.5-4(-4.5) cm, at middle 0.7-1.7 mm diam, bluntly 3-ribbed dorso-laterally, narrowly margined and open-sulcate ventrally; rachis (1-) 1.5-6(-6.5) cm, usually a little longer than the petiole; glands between all except the distal (or distal and penultimate) pairs, stipitate, the slender stipe villosulous, the whole in profile 2-4.5(-5) mm tall, the narrowly lance-attenuate body 0.2-0.4 mm diam; pulvinules 1.2-2.3 mm; lfts 3-5 pairs, ± accrescent distally but either the distal or the penultimate pair largest, these broadly obovate- cuneate, obovate, or subrhombic-obovate 2-5.5 x 1-3.1(-3.4) cm, 1.5-2 times as long as wide, at apex rounded or depressed-deltate-acuminulate, conspicuously mucronate, at oblique base inequilaterally rounded or distally cuneate, the midrib and 4-6 pairs of camptodrome secondary veins immersed or almost so above, sharply prominulous and often pallid beneath, the tertiary venulation imperceptible or almost so.

    Peduncles (3-)5-17(-20) mm; racemes shortly or subumbellately 2-6(-7)-fld, the axis 0-4(-7) mm in fruit; bracts resembling stipules but smaller, 2-7(-10) mm; pedicels at anthesis no longer than sepals, often but not always subtended on one side or another by a gland resembling those of petiole, in fruit stiffly erect-ascending, much thickened, 2.5-5.5 mm; fl-buds nodding subglobose, pilosulous at or toward the base but glabrate distally; sepals thin-textured, greenish at middle but pallid or yellowish toward margins, moderately graduated, oblong-obovate or suborbicular, the longer inner ones up to 3-4.3 mm; petals yellow, often fading (or drying) brick-red, not strongly veined, glabrous dorsally, fleetingly expanded and lasting no more than 1 day, sometimes remaining crumpled and scarcely longer than calyx, in outline obovate-cuneate obtuse or subemarginate, the 2 abaxial ones slightly oblique, the longest petal (3-)4-8 mm; androecium glabrous, the 3 staminodes minute, the 7 fertile members all similar but slightly accrescent toward abaxial side of fl, the filaments 0.6-1.7 mm, the anthers lanceolate or lance-ovate in outline 0.9-2.4 mm, slightly incurved, contracted near apex into a beak 0.2-0.5 mm, this precociously dehiscent into a 1-pored pollen-cup facing inward; ovary densely white-setose-pilose; style (1.2-) 1.4-2.4 mm, strongly incurved, at apex dilated and (0.35-)0.4-0.6 mm diam at the truncate orifice; ovules (5-)7-12.

    Pod erect, long persistent (even after fall of all lvs), sessile or almost so, linear- oblong in outline, straight or slightly incurved, 2.5-5.5 x 0.3-0.4(-0.45) cm, bluntly compressed-tetragonal, bicarinate by the thick cordlike sutures, the turgid valves at first firm green, turning brown or ultimately blackish, venulose and rufous-setose, deeply impressed-sulcate over each intraseminal septum and thus appearing but not truly lomentaceous, the seminal cavities (3-)3.5-5 mm long; dehiscence tardy, basipetal through both sutures; seeds obliquely descending across the cavity, irregularly compressed-rhomboid 3.2-4.4 x 2-3 mm, the testa smooth or minutely granular, brownish-olivaceous or finally castaneous, crackled or eventually flaking, the lustrous oblanceolate areole straight or commonly incipiently sigmoid, nearly as long as the seed-face, 2.8-4.2 x 0.6-1 mm.—Collections: 170.—Fig. 10 (androecium), 14 (pod + seed).

    Waste places, both urban and rural, disturbed brush-woodlands, savannas, shores and beaches, becoming a troublesome colonial weed of pastures where avoided by herbivores, primarily of the lowlands but ascending to 700 m in Brazil, 1200(-1750) m in Mexico and 1300 m in Honduras, bicentrically dispersed in eastern Brazil and in n. Central America, Mexico and the Antilles, sporadically weedy elsewhere: Brazil (s. Maranhao to Ceara, Bahia, n.-w. Minas Gerais and e.-centr. Goias); Bahamas, Cuba, Jamaica, Hispaniola, Puerto Rico; Mexico (s. Tamaulipas to Yucatan Peninsula, Chiapas, across the s. states to Jalisco and thence n. along the Coastal Plain to s. Sonora); Guatemala, Belize, El Salvador to Nicaragua; Barbados; n. Venezuela (Lara, e. to Nueva Esparta); Ecuador (Galapagos Is.).—Fl. throughout the year except when drought-inhibited, sometimes surviving the dry season and regenerating as softly woody herbs.—Charamasca, frijolillo (Mexico); xtulu-baya (Maya); pica-pica (Venezuela); matopasto (Brazil).