Senna ligustrina

  • Title

    Senna ligustrina

  • Authors

    Howard S. Irwin, Rupert C. Barneby

  • Scientific Name

    Senna ligustrina (L.) H.S.Irwin & Barneby

  • Description

    131.  Senna ligustrina (Linnaeus) Irwin & Barneby, comb. nov. Cassia ligustrina Linnaeus, Sp. Pl. 378. 1753.—"Habitat in Virginia, Bahama."—Described from plants grown at Hartekamp and later at Uppsala and on illustrations provided by Dillenius and Martyn. Lectoholotypus, Herb. Cliffort., Cassia No. 7 ex parte, BM!, one of 4 sheets (annotated as Senna ligustrina by Barneby, 1980) filed under the common title Senna occidentalis odore opii virosi Or obi pannonici foliis mucronatis glabris (the others represent holotypic Cassia occidentalis and Senna marilandica).—The lectotypus proposed by Fawcett & Rendle, Fl. Jam. 4: 105. 1920, by implication, LINN 528/25!, = Senna sophera; the habitat "Virginia," taken from Gronovius, Fl. Virg. 47 = S. marilandica.

    Cassia bahamensis P. Miller, Gard. Diet. ed. 8, Cassia no. 9. 1798.—". . . grows naturally in the Bahama Islands, from whence I received the seeds."—Holotypus, "Cassia Bahamensis pinnis foliorum mucronatis . . BM! = BH Neg. 5771.—Equated by Martyn in Miller, Diet. ed. 9, Cassia no. 24, with C. ligustrina.—Non C. bahamensis sensu Bentham, 1871, p. 541, quae = Senna mexicana var. chapmanii.

    Cassia ligustrina var. jaegeriana Urban, Symb. Antill. 5: 360. 1908.—"Hab. in Haiti in montibus Le grand fond de Port-au-Prince dictis . . . 1000 m alt., m. Dec. fl. et fr.: Jaeger n. 36."— Holotypus, †B; presumed isotypus, Jaeger s.n. ex Haiti, NY!—Equated by Britton & Rose, 1930, p. 257, with Ditremexa confusa, q.v. infra.

    Cassia ligustrina var. eggersiana Urban, Symb. Antill. 5: 360. 1908.—"Hab. in Santo Domingo in monte Barrero [±19°N, 17°40'W in prov. La Vega] 330 m alt., m. Majo flor . . .: Eggers n. 2063."—Holotypus, †B; no isotypus found.—Equated by Britton & Rose, 1930, p. 257, with Ditremexa confusa, q.v. sequ.

    Ditremexa confusa Britton ex Britton & Rose, N. Amer. Fl. 23(4): 257. 1930.—"Type from between Higuey [Higuey] and Gato, Santo Domingo, December 6, 1909, N. Taylor 430 "— Holotypus, NY!

    Peiranisia turquinae Britton ex Britton & Rose, N. Amer. Fl. 23(4): 267. 1930.—". . . First and Main Peaks, Pico Turquino, Oriente, [Cuba,] October 12-14, 1924, G. C. Bucher 78."— Holotypus, NY! isotypus, US 12227921—Cassia turquinae (Britton & Rose) Leon, Contrib. Ocas. Mus. Hist. Nat. Colegio "De La Salle" 9: 12. 1950.

    Senna Americana ligustri folio Plumier ex Tournefort, Inst. Rei Herb. 618. 1700, primary source of epithet ligustrina.

    Cassia Bahamensis pinnis foliorum mucronatis, angustis . . . Martyn, Pl. Rar. 21. 1728.—Described from plants grown from seed sent by Mark Catesby from the Bahamas, more precisely, acc. Dillenius, Hort. Eltham. t. 259 (legum. exclus.) 1732, from New Providence.—This is the ancestor, via Miller, Diet. ed. 1, Cassia no. 5. 1731 and successive editions, of C. bahamensis Miller (q.v. supra).

    Cassia (no. 8) foliolis septem parium lanceolatis . . . Linnaeus, Hort. Cliff. 159. 1757, equated by Linnaeus with the plants of Plumier and Dillenius mentioned in 2 preceding paragraphs, described from plants grown at Hartekamp doubtless from the stock introduced by Catesby; hence direct ancestor of C. ligustrina Linnaeus (q.v. supra).

    Cassia ligustrina sensu Edwards, Bot. Reg. 2: pl. 109. 1816; Curtis, Bot. Mag. 43: pl. 1829. 1816; Colladon, 1816, p. 111; Vogel, 1837, p. 32 (exclus. syn. Willdenov.); Bentham, 1871, p. 534; Britton, Fl. Bermuda 171 + fig. 1918.

    Ditremexa ligustrina sensu Britton & Rose, 1930, p. 258.

    Amply leafy, precociously maturing but potentially frutescent herbs from black roots, at anthesis (4-)6-20("-30") dm, at first 1-stemmed becoming bushy with 1-several slender leafless trunks, the hornotinous branchlets densely leafy, the whole appearing glabrous but young stems, lf-stalks, lft-margins and axis of inflorescence loosely strigulose, pilosulous or rarely hirsutulous with pale subappressed, incurved or spreading hairs up to (0.2-)0.3-0.6(-0.7) mm, the weakly ill- scented foliage subconcolorous or paler beneath, the faces of lfts often glabrous except for a puberulent line along midrib above and scattered minute thickened trichomes beneath, rarely either or both faces pilosulous overall, the racemes mostly crowded in axils of upper lvs or of vestigial lf-stalks to form a short but not or only shortly exserted subcorymbose panicle.

    Stipules erect, thinly herbaceous, early pallid then dry caducous (lacking from all but vigorous young stems), lanceolate, lance-oblong or narrowly ovate acute (2-)3-6(-7) x 1-2.2 mm, at base often obliquely dilated and obtusely amplexicaul-auriculate on side further from petiole.

    Primary cauline lvs l-2.2(-2.7) dm (occasional shorter ones in the panicle or on lateral spurs not further mentioned); petiole including often discolored but not much dilated pulvinus (1.7-)2-4.5(-6) cm, at middle 0.7-1.7(-1.9) mm diam, obtusely ribbed dorso-laterally, openly shallow-sulcate ventrally; gland most commonly inserted either next to pulvinus or below middle of petiole at a point up to 11 (-13) mm distant from it, but in some lvs between the proximal pair of lfts, in either case either stipitate or subsessile, in profile 1.7-3(-3.5) mm tall, the slenderly ovate or lance-attenuate acute or subacute, erect or incurved body 0.4-1 mm diam, similar glands sometimes between the distal or between this and the penultimate 2-3 pairs of lfts; rachis 5-13(-15) cm, the longer interfoliolar segments (8-)10-26(-35) mm; pulvinules 1.3-2.3 mm; lfts (4-)5-8 pairs, ± accrescent distally but the penultimate pair often longest, the longer lfts obliquely lanceolate, lance-acuminate, or ovate and more abruptly and shortly acuminate 3-7 x 0.6-2(-2.2) cm, (2.5-)2.7-7 times as long as wide, at base on proximal side varying from broadly cuneate to shallowly cordate, cuneate on distal side, the margins weakly revolute or distally plane, the straight midrib impressed-canalicu- late above, sharply cariniform beneath, the pinnate venulation of 8-15 pairs of camptodrome secondary nerves either fully immersed or faintly raised on one or both faces, tertiary venulation almost or quite invisible.

    Peduncles narrowly ascending (1.1-) 1.6-4.5(-6.5) cm; racemes rather densely (3-)5-30-fld, the glabrous buds ± obliquely ascending, the expanded fls subcorymbose, the axis including peduncle becoming (1.5-)2-8.5(-10) cm; bracts submembranous pallid or yellowish, rarely firm castaneous-fuscous, lanceolate, lance- oblong, -elliptic or ovate, commonly 2.5-6 x 1-2.5, sometimes to 10 x 4 mm, early caducous; mature pedicels (l-)1.3-2.3(-2.6) cm; sepals greenish, yellow or fuscous, obovate not strongly graduated, the membranous-margined outer ones up to 5-7.5 mm, the thinner-textured inner ones up to 6.5-8.5(-9) mm; petals glabrous, yellow drying whitish or ochroleucous brown-veined, of ± equal length but the emarginate banner widest, the lateral and abaxial petals obovate beyond short claw, the longest petal 12-15 mm; androecium glabrous, the staminodes 1.3-1.6 mm wide, the filaments of 4 median stamens 1.5-2.6 mm, of 2 larger abaxial ones 4.8-6.3 mm, of the centric abaxial one 3-4 mm, the anthers of 4 median stamens including shallowly obliquely 2-lipped beak 3.6-5 mm, that of the sterile centric abaxial one 1.8-5 x 0.4-0.7 mm, those of 2 long abaxial ones, measured to obscure infraterminal constriction, (4-)4.2-5.8 x 1.3-1.8 mm, their beak (0.8-)0.9-1.2 mm, its thickened abaxial lip projecting (0.4-)0.5-0.7 mm beyond orifice; ovary strigulose, thinly pilosulous or minutely scaberulous laterally, the sutures often glabrous, the pubescence early sparse or evanescent; style ±2.5-3 mm, abruptly thickened distally and incurved through ±140-300°, at the introrsely directed barbellate stigmatic cavity (0.4-)0.45-0.6 mm diam; ovules (36-)40-52(-56).

    Pod ascending, gently curved outward, the stipe 1.5-2.5 mm, the linear piano- compressed body (7-)9-14 x (0.5-)0.6-0.85 cm, the papery valves brown or purplish-castaneous paler-margined, scarcely venulose, a little elevated over and depressed between each successive pair of seeds, the membranous interseminal septa 1.5-3.3(-4) mm apart, the seed-locules wider than long; seeds obliquely transverse, varying in outline (sometimes in one pod) from broadly obovate to oblong-elliptic, 2.7-4.5 x 1.7-2.8 mm, plump but compressed usually parallel to the valves, rarely (in narrow locules) a little rotated on their long axis and incipiently compressed parallel to the septa, the smooth dull or sublustrous testa olivaceous or smoke-gray usually paler around the blackish areole and fuscous at the periphery, the obovate or elliptic areole (1.8-)2.2-3.3 x 1.1-2 mm.—Collections: 80.

    Open woodlands, thickets, hammocks (Florida), coppice (Bahamas), often in seasonally wet ground, coming out into pastures, roadsides, coastal sands and coral reefs, from near sea level up to 1500 m in Jamaica and 1200 m in Hispaniola, locally plentiful in peninsular Florida s.-ward from 28°30'N (Isely, 1975, map 46), the Bahamas n.-w. from Exuma Sound, Cuba (all provinces), Jamaica, Cayman Is. and Hispaniola; Isla Colon, Panama (Bocas del Toro, ?native); cultivated and locally naturalized in Puerto Rico and Bermuda; the report (Britton & Millspaugh, Bahama Fl. 167) from Guyana requires verification.—Fl. intermittently through the year, most prolifically VIII-IV, the pods often long persistent after fall of seeds.—Privet senna; frijolillo; brusca.

    Senna ligustrina is variable in pubescence and width of lfts, but we have not found any significant correlation between these features or between either of them and dispersal. The leaflets are commonly glabrous on both faces or glabrous above and charged beneath with minute thickened glandiform trichomes. A notable exception is Liogier 14166 from Sa. de Bahoruco in southwestern Dominican Republic, which is hirsutulous throughout with vertical hairs, and intermediate states of vesture are not infrequent. The populations from the central highlands of Dominican Republic have relatively broad leaflets (D. confusa), but not or hardly broader than some in Florida. The typus of Peiranisia turquinae, inexplicably referred by Britton to a different genus from Ditremexa ligustrina, consists of branch-tips bearing only small upper leaves. It is unusual in the species as a whole because of its large dark-colored and thick-textured floral bracts, but we can find no supporting difference. More complete plants collected later by Leon on the slopes of Pico Turquino (nos. 10743, 10950) were both recognized by Britton himself as Dit. ligustrina. Peiranisia turquinae appears distinct only in the context of the wrong genus.