Senna nitida

  • Title

    Senna nitida

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Senna nitida (Rich.) H.S.Irwin & Barneby

  • Description

    28.  Senna nitida (L. C. Richard) Irwin & Barneby, comb. nov. Cassia nitida L. C. Richard, Actes Soc. Hist. Nat. Paris 1: 451. 1792.—Described among plants "e Cayenna . . . missarum a domino LeBlond," but actually from West Indies, the holotypus labelled "Sti. Johannis-Sti Thomae-Tortolae," P (hb. Richard.)!—Misidentified by DeCandolle as C. apoucouita, and doubtfully referred by Bentham (1871, p. 523) to C. viminea, this was recognized as the earlier name for Chamaefistula antiliana by Amshoff, 1939, p. 22.

    Chamaefistula antillana Britton & Rose ex Britton & Wilson, Sci. Surv. Porto Rico & Virgin Is. 5 (Botany . . . Spermatophyta), pt. 3: 369. 1924.—"Type from St. Thomas ([.E. G.] Britton and [Delia] Marble 400)."—Holotypus, collected 5-7.II. 1913 (fl, fr jun), NY! isotypus, US!—Cassia antillana (Britton & Rose) Liogier, Bull. Torr. Club 90: 187. 1963.—Ch. antillana sensu Britton & Rose, 1930, p. 233; Addisonia 12 (3): 41, pl. 405. 1927.

    Cassia quinquangulata sensu Bentham, 1871, p. 523, p.p., quoad pi. antill. Oersted, et Masson.

    Closely akin to and resembling S. quinquangulata, weakly fruticose becoming sarmentose to 7 m, appearing glabrous below the minutely incumbent-pilosulous inflorescence but the angulate young branchlets, ventral face of lf-stalks, pulvinules and (often) lower face of lfts sparsely puberulent with appressed hairs ±0.1-0.2 mm, the bicolored foliage essentially as in C. quinquangulata except on average slightly less ample, the leaf-blades often brownish-mottled and pallid- venulose above.

    Stipules 4-9 x 0.4-1.5 mm.

    Lvs below inflorescence 8-17 cm; petiole (1-) 1.3-3.5 cm, at middle 0.7-1.2 mm; rachis 9-28 mm, shorter than or equalling petiole; glands between each pair of lfts lance-ellipsoid or narrowly fusiform acute or obtuse glabrous 0.35-0.7 mm diam, including the glabrous or rarely puberulent stipe 1.6-3.5 mm tall; pulvinules (2-)2.5-4.5 mm; distal pair of lfts 6-11 x (2.5-)2.8-5(-5.5) cm, ±1.8-2.8 times as long as wide.

    Peduncles with raceme-axis 2-6 cm; racemes 7-20-fld; bracts obovate or lanceolate obtuse or acute 1.5—4 mm, concave and folded over the young buds but thrown off as pedicel elongates; pedicels 14-28 mm; sepals yellowish, not much graduated, elliptic or narrowly obovate-elliptic obtuse cymbiform up to 3.2-5.4 mm, at anthesis apparently nerveless but becoming rather prominently 3-5- nerved in age, usually minutely puberulent within; petals (of ser. Bacillares) up to 16-22 mm when fully expanded; functional stamens 5 or 6, the 4 median always present but 1 or 2 of the 3 abaxial wanting, the filaments puberulent or glabrate, of the 4 median stamens 1.2-1.8 mm, of the abaxial often a little longer up to 2-2.8 mm, the anthers usually puberulent distally, sometimes glabrous, those of 4 median stamens scarcely incurved 3.6-5.7 mm, with very short depressed, often 1-porose beak ±0.3-0.5 mm, those of 1-2 abaxial ones similar but commonly slightly smaller 2.6-4.5 mm, their beak similar or slightly more porrect; ovary densely strigulose; style moderately swollen, 0.7-1.05 mm diam just below the hollow stigma, the orifice 0.3-0.5 mm diam; ovules 76-104.

    Pod like that of S. quinquangulata except on the average shorter and wider, the stipe 2-4 mm, the body (8-) 10-18 x 1.2-1.9 cm, the ventral suture ±2 mm wide, without thickened border, the valves coarsely but not very prominently transverse-venulose; seeds biseriate, turned broadside to the septa, compressed- obovoid 6-7.2 x 4-4.6 mm, the testa atropurpureous lustrous cross-crackled, exareolate.—Collections: 45.

    Mountain forest, disturbed woodland, thickets, and persisting at forest border or in hedges, 50-850 m, Porto Rico (w., e.-centr. and e. districts), Virgin Is. (St. Thomas and Tortola), and Leeward Is. (St. Kitts); ?Haiti, cf. discussion). Fl. VIII-II.

    A close relative of S. quinquangulata and S. viminea, differing from both in the loss of one or two of the abaxial set of stamens, and fully allopatric. Of ser. Bacillares, S. bacillaris alone shares its insular range between Puerto Rico and St. Kitts and this differs greatly in its strongly asymmetric, plane-margined leaflets, zigzag primary inflorescence-axis, heptamerous androecium and thick-margined sutures of the pod. The fully expanded petals of S. nitida are ordinarily longer in relation to the small calyx than those of S. quinquangulata, the sepals are more strongly veined in age, the foliage is on the average smaller, the style less dilated under the stigma, and the pod at once broader and shorter; but no one of these differential characters can be relied on absolutely to separate all forms of S. quinquangulata, of which the pod, moreover, is still very poorly known. The yet shorter pod is perhaps the best morphological character separating S. viminea which, however, is in practice recognized as the only Jamaican representative of this immediate alliance, further notable for its full set of seven anthers. In describing Chamaefistula antiliana Britton & Rose gave no diagnosis whatever, but in North American Flora compared it with S. viminea; while their contrast in the pods has proved a valid one, that involving width of leaflets cannot be confirmed in the material now available.

    The two specimens of S. nitida known to Bentham were referred by him (1971) to Cassia quinquangulata, that of Masson from St. Kitts without comment, that of Oersted from St. Thomas with a remark on its nearly glabrous foliage. The correct application of the name C. nitida, which Bentham thought to have originated in French Guiana and guessed to be synonymous with C. viminea, was first established by Amshoff (1939, l.c.).

    A sterile specimen from Haiti (Massif des Matheux, 1500 m, 16.III.26, Ekman 5760, US) is highly suggestive of C. nitida, but could also represent an outlying population of Jamaican C. viminea. We have seen no other Bacillares of this type from Hispaniola.