Senna stenophylla

  • Title

    Senna stenophylla

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Senna stenophylla (Benth.) H.S.Irwin & Barneby

  • Description

    133.  Senna stenophylla (Bentham) Irwin & Barneby, comb. nov. Cassia stenophylla Bentham, Trans. Linn. Soc. London 27: 535. 1871—"Cuba, Wright, n. 1601."—Lectoholotypus, Wright 1601 ex parte, collected 18.X (flor) at ‘Farallones Potrero San Andre[s],’ K (hb. Hook.)! = NY Neg. 1427; paratypus, Wright 1601 ex parte (fr), K (hb. Hook.)! = NY Neg. 1428.—Cassia decipiens sensu Grisebach, Mem. Amer. Acad. II, 8: 179. 1860 (non Desvaux)—"in rupibus ad Nouvelle Sophie, Nov. . . . Wright 1601.—Leoncassia stenophylla (Bentham) Britton ex Britton & Rose, N. Amer. Fl. 23(4): 268. 1930.

    Erect 1-few-stemmed, basally suffrutescent, simple or distally branching herb ±0.8-1.2 m, appearing and sometimes truly glabrous, but the sharply angulate young stems and terminal branchlets often remotely minutely strigulose with appressed hairs to 0.15-0.35 mm, the abundant but very narrow grasslike foliage sublustrously olivaceous, paler beneath, the racemes all lateral, axillary to and surpassed by lvs, or some late ones crowded into a small leafy, scarcely exserted panicle.

    Stipules erect, resembling lfts in herbaceous texture and revolute margins, linear-lanceolate 4-11 x 0.6-1 mm, sometimes a trifle dilated at base on side further from petiole, deciduous before the lf.

    Lvs 8-19 cm; petiole including little-swollen pulvinus 9-24 mm, at middle 0.5-0.8 mm diam, bluntly keeled dorsally, narrowly thick-margined and openly shallow-sulcate ventrally; rachis 3.5-10 cm, the interfoliolar segments (8-)10-19 mm; gland inserted on petiole (2-)3-7 mm distant from pulvinus, ascending stipitate, in profile (1.5-)2-3.3 mm tall, the narrowly ovoid or lance-ovoid acute or subobtuse body 0.3-0.8 mm diam, and similar but smaller glands often between the ultimate and penultimate pairs of lfts; pulvinules 0.5-1.2 mm; lfts 5-8 pairs, accrescent distally, all linear to linear-lanceolate-attenuate, the distal pair 30-70 x 0.7-2.5 mm, (25-)30-70 times as long as wide, the margins recurved or strongly revolute, the midrib impressed-canaliculate above, cariniform beneath, an obscure secondary venulation visible only beneath.

    Peduncles (1.7-)2.5-4.5 cm; racemes rather densely (4-)7-25-fld, the axis becoming (3-)5-35 mm; bracts (little known) submembranous linear-lanceolate 4-7 mm, deciduous before anthesis; mature pedicels 2-3 cm; fl-buds nodding glabrous; fls at anthesis little known, apparently little different from those of S. ligustrina, the oblong-obovate subequal sepals ±8-10 mm, the petals to ±13 mm; androecium glabrous, the 3 staminodes 1.3-1.5 mm wide, the filaments of 4 median stamens ±1.5 mm, of 2 large abaxial ones dilated ±6 mm, of the sterile centric abaxial one ±3 mm, the anthers of 4 median stamens including their very short, obliquely 2-lipped beak ±4 mm, those of 2 abaxial ones brown, measured from sagittate base to subterminal constriction ±5-6 x 1.5 mm, their beak ±1 mm, its thickened abaxial lip ±0.6-0.7 mm, the anther of the centric stamen sterile ±3 x 0.6 mm; ovary minutely puberulent, early glabrate; style ±2 mm, shaped like that of S. neglecta or S. mexicana, at incurved apex 0.4-0.5 mm diam; ovules 34-44.

    Pod ascending, the stipe 2-3 mm, the straight or gently outwardly arched body narrowly linear piano-compressed 11-15 x 0.46-0.6 cm, the thinly papery, pur- purascent, when ripe brown valves narrowly pallid-margined, shallowly depressed between seeds, the interseminal septa 2.5-4 mm apart, the seed-locules mostly a little broader than long but some (especially distally) a little longer than broad; seeds (little known) broadly obovoid, compressed parallel to valves ±3.5 x 3 mm, pinched at hilum, the smooth dull brown-olivaceous testa girdled by a dark line, the elliptic-obovate areole 2.2-2.5 x 1-1.3 mm.—Collections: 7.

    Dry brushy hillsides and open woodland, 5-200 m, local along the coastal foothills of Sa. Maestra, Oriente, Cuba.—Fl. IX-III, the old pods sometimes long persisting.

    One of several singular Cassieae endemic to eastern Cuba, S. stenophylla is readily recognized by the extremely narrow grasslike leaflets. The petiolar glands and the morphology of the flower, especially of the recurved style, closely resemble those of S. ligustrina, of which it may well be a local derivative.