Senna sophera (L.) Roxb.

Authors

Howard S. Irwin, Rupert C. Barneby

Authority

Irwin, Howard S. & Barneby, Rupert C. 1982. The American Cassiinae. A synoptical revision of Leguminosae tribe Cassieae subtrib Cassiinae in the New World. Mem. New York Bot. Gard. 35, part 1: 1-454.

Family

Caesalpiniaceae

Scientific Name

Senna sophera (L.) Roxb.

Type

lectoholotypus (Trimen, J. Linn. Soc., Bot. 24: 141. 1887; Fawcett & Rendle, Fl. Jamaica 4: 105. 1920; confirmed by De Wit, 1955, p. 266), BM (hb. Hermann.)!—Chamaefistula sophera (Linnaeus) G. Don, Gen. Hist. Diehl. Pl. 2: 452. 1832. Cassia occidentalis

Synonyms

Cassia sophera L., Chamaefistula sophera (L.) G.Don, Cassia occidentalis var. sophera (L.) Kuntze, Ditremexa sophera (L.) Britton & Rose, Cassia frutescens Mill., Cassia sophera var. ligustrinoides Benth., Cassia patula Aiton, Cassia canca Cav., Cassia linearis Michx., Cassia lineata Sw., Cassia proboscidea Pollard

Description

Species Description - Erect simple, early bushy-branched, precociously flowering, soon frutescent herbs from black roots, at anthesis commonly 5-12 dm but in rich soil or in age up to 2 (perhaps 3) m tall, the softly woody leafless old stems corymbosely branched distally, the whole in habit, pubescence, stipules and petiolar glands resembling at anthesis small-lvd S. occidentalis, but the herbage only weakly malodorous, the racemes more strongly pedunculate and their axes commonly glabrous or at most weakly granular-puberulent, decisively different only in the style and pod. Major lvs 7-18(-21) cm; petiole 1.5-4(-4.7) cm; petiolar gland borne adjacent to pulvinus 0.5-1.2 x 0.6-1.4 mm; rachis 4- 11 (- 12) cm; lfts (3-)4-6(-8) pairs, the distal pair lance- or ovate-acuminate (2-)2.5-6 x (0.7-)0.8-2.1 cm, (2.4-)2.7-4.5(-5) times as long as wide. Peduncles (5-)6-23 mm; racemes subumbellately l-4(-5)-fld, the axis 0-4(-5) mm; bracts usually lanceolate or linear-oblanceolate, abruptly acute, sometimes ovate-acuminate, 5-13 x (1.6-)2-4 mm, the thin-textured blades green or yellowish, when elongate involute over the ascending fl-buds; mature pedicels (8-)9-15(-18) mm; outer sepals 5-6.5 mm, the inner ones 6-8 mm; petals of S. occidentalis, but averaging shorter, the longer ones 10-12.5 mm; androecium essentially that of S. occidentalis, the staminodes sometimes up to 1.6 mm; ovary strigulose, sometimes only thinly so; style 2-3.5 mm, at apex dilated and strongly incurved, 0.5-0.7 mm diam at the introrsely oriented stigmatic cavity; ovules 62-84. Pod erect or stiffly ascending subsessile, the ripe body cylindric or (when short) linear-ellipsoid, straight or gently incurved, (5-)6-9.5(-10) x 0.7-1 cm (when strongly flattened in press apparently up to 1.2 cm diam), the sutures scarcely prominent, the valves broadly pale-margined, dark purple-, when dry black- striped down the middle, not or scarcely elevated over individual seeds, early glabrate, the transverse seed-locules mostly 1.3-2.3 mm long, as wide as the cavity or a few near the pod’s apex a little longer; seeds disposed horizontally in two interdigitating series along the length of the pod, each turned to present its broader, areolate faces to the septa, plump but compressed parallel to the septa, in outline broadly or narrowly (when much crowded sometimes irregularly) obovate (2.4-)2.8-4 x (2-)2.3-3.2(-3.5) mm, the testa smooth or sparsely pitted ochraceous, light-brown or castaneous, dull or sublustrous, crackled in age, the elliptic or obovate-elliptic areole 1.2-2.3 x 0.7-1.2 mm; x = 14 (Irwin & Turner, 1960).—Collections (neotropical only): 63.

Distribution and Ecology - Roadsides, old fields, ditches, waste places and rubbish heaps, occurring singly or in thickets, in the Neotropics everywhere weedy, mostly below 600 m but ascending in Mexico and n. Venezuela to ±1000 m and in the Colombian Andes to 1850 m, discontinuously widespread around the Caribbean from Bahamas and w. Cuba through the Greater and Lesser Antilles to Barbados, Trinidad and across n. Venezuela to centr. Colombia (s. to Narino), local in Panama (Canal Zone) and Mexico (Veracruz; centr. Oaxaca); coastal Guyana; 1 record from e. Brazil (Bahia).—Fl. intermittently through the year, most prolifically following rains.

Discussion

Students of Cassia, from Bentham (1871, p. 532) onward, have commented repeatedly on the difficulty in distinguishing the obviously related and habitally similar C. occidentalis and C. sophera, and their perplexity is reflected in the number of misidentified specimens encountered in herbaria. In reality the two species are readily recognized at anthesis by length of peduncles and structure of the style, and later on most decisively by the compression of the pod and disposition of the seeds within it. The differential characters which we consider crucial are set out in dichotomies 12/12 and 19/19 of the key to the series and require no further emphasis. Generally speaking American S. sophera, while it flowers as precociously as S. occidentalis, is potentially more enduring and becomes genuinely shrubby in age, when its leaflets are on the average smaller. But the habit is seldom evident in the herbarium and there is a wide overlap in size of leaflets which are indistinguishable in outline, vesture or venation. Our description of S. sophera is based exclusively on American material and evades the vexed question of the intraspecific variation and its taxonomic consequences in eastern Asia and Australia. With a single exception of a modern collection from Bahia, neotropical S. sophera is essentially uniform. The sessile and subglobose or mounded petiolar gland is truly basal, inserted next to the pulvinus; the leaflets are 4-6 pairs; the flower-buds and usually all axes of inflorescence are glabrous; the petals are small, not over 12.5 mm long; and the pod, unless some ovules abort, is mostly 6.5-9.5 cm long. Nomenclaturally typical S. sophera from Sri Lanka and continental India has a more cylindric gland inserted sometimes well above the pulvinus, leaflets up to 10 pairs, sepals more often pubescent than not, and petals up to 15 mm long; but the smoothly cylindroid pod is the same as that of the American plant and we therefore follow tradition in treating them as aspects of one species, though very likely properly distinguishable at varietal level. Variation in Asia encompasses further a large-flowered south Chinese plant called by Bentham C. sophera var. torulosa, in which the valves of the ripe pod are corrugately elevated over the seeds. And in Australia, New Caledonia and Fiji the complex is represented by a series of small-fruiting relatives, differing among themselves in petiolar gland, vesture, and number or shape of leaflets, that have been variously treated either as part of C. sophera sensu lat. (Bentham, 1871, l.c., Fl. Austral. 2: 283. 1864), as a var. schinifolia, or (Symon, 1966, p. 89—91) as allied but distinct species C. barclayana and C. planitiicola, a controversy which we cannot profitably enter into without access to much more extensive Australasian material of the group. Because we have seen no Asiatic S. sophera that matches at every point the American populations of the species we suspect that our circum-Caribbean and Colombian plant may be indigenous (even though now primarily weedy) and varietally distinct from its paleotropical analogues. The exception from Bahia (Hatschbach 39514, NY, unfortunately only in young flower) already mentioned has the higher number of leaflets and puberulent sepals commonly encountered in Indian S. sophera and may represent a modern introduction independent of the rest. Until our deliberately limited picture of American S. sophera can be integrated with an equivalent body of data from the Old World, the time has not come to reevaluate the long list of synonyms quoted by Bentham (1871, l.c.), the majority of which were based on plants grown in European conservatories, often without record of the original source. We have examined critically only those names based on types known to be American. The only varietal epithet at present potentially available for Neotropical S. sophera is ligustrinoides Bentham which was, however, based on a mixture of Jamaican Cassia frutescens Mill, and Indonesian C. coromandeliana Jacqu. and therefore will lack precise application until it is lectotypified.

Common Names

Sene zombi , Brusca

Distribution

Canal Zone Panamá Central America| Veracruz Mexico North America| Oaxaca Mexico North America| Guyana South America| Bahia Brazil South America| Venezuela South America| West Indies| Colombia South America|