1.  Cassia fistula Linnaeus, Sp. Pl. 377. 1753.—"Habitat in India, AEgypto."— Described first by Linnaeus in 1737 (Hort. Cliffort. 158, Cassia No. 2) and again in 1747 (Fl. Zeylan. 63) from a spm in Hermann’s herbarium, but the concept enriched from the first by earlier descriptions of Bauhin (whence the epithet), J. Commelijn (Hort. Med. Amstel. 1: 215, t. 110. 1697) and Rheede tot Draakestein (Hort. Ind. Malabar. 1: t. 22. 1686).—Lectoholotypus (Fawcett & Rendel, 1920, p. 102, confirmed by DeWit, 1955, p. 209), Hermann s.n., BM (hb. Hermann.).— Alf from Cliffort’s garden survives in Herb. Cliff., Cassia No. 1, BM! and another, source unknown, in LINN 528/12 (as ‘C. falcata')!— Cathartocarpus fistula (Linnaeus) Persoon, Syn. Pl. 1: 459. 1805. Bactyrilobium fistula (Linnaeus) Willdenow, Enum. hort. berol. 440. 1809.

Cassia excelsa Humboldt, Bonpland & Kunth, Nov. Gen. & Sp. 6 (fol): 267. 1824.—. . prope Porto-Cabello et in convallibus Araguensium [n. Venezuela] . . —Holotypus, P-HBK!— Cassia bonplandiana DeCandolle, Prod. 2: 490. 1825, a legitimate substitute (non C. excelsa Schrader, 1821). Cathartocarpus excelsus (Humboldt, Bonpland & Kunth) G. Don, Gen. Hist. Diehl. Pl. 2: 453. 1832.—Equated with C. fistula by Bentham, 1870, p. 92.

Cassia fistuloides Colladon, Hist. Cass. 87, t. 1. 1816.—"Hab. in calidis Mexici.’—Described from plate and manuscript of Sesse & Mocino, Fl. Nov. Hisp., the plate, long lost, copied at G.—Lectotypotypus, Hb. Sess. & Moc. 1141 & 1146, MA!—Cathartocarpus fistuloides (Colladon) G. Don, Gen. Hist. Diehl. Pl. 2: 454. 1832.—Equated with C. fistula by Bentham, 1870, p. 92.

Cassia fistula sensu Bentham, 1871, p. 514; Sesse & Mocino, Pl. Nov. Hisp. 59. 1893; Schery, 1951, p. 44, fig. 117; DeWit, 1955, p. 207-212, q.v. for exhaustive citation of literature, synonymy based on Old World types, and discussion of ecology and dispersal in Asia; Isely, 1975, p. 96, map 39 (cult, in Florida).

Slender deciduous or semideciduous trees potentially attaining 20 m and trunk diam up to 6 dm but often flowering as treelets, with smooth gray bark and narrowly ascending, then out- or downwardly arching branches, the livid annot- inous branchlets ridged and lenticellate, the hornotinous ones together with lvs (except the sometimes glabrous upper face of lfts) and axes of inflorescence all finely minutely puberulent or thinly pilosulous with appressed or less often spreading-incurved hairs up to 0.05-0.2(-0.25) mm, the incipient lvs and fl-buds transiently silky-canescent, the amply chartaceous lfts bicolored, rich green and (dry) dull or sublustrous above, pallid or subglaucescent beneath, the openly many-fld, pliantly pendulous racemes of large yellow fragrant fls arising, singly, geminate or paniculately few-branched, directly from annotinous branchlets and ± coeval with fall of old and flush of new foliage.

Stipules erect appressed, broadly or narrowly subulate 1-2 mm, caducous before expansion of associated lf.

Lvs, disregarding the often depauperate first lf of annual growth, (1.5-)2-5.5(-6.2) dm; petiole including wrinkled pulvinus 4-7.5(-9) cm, at middle 1.3-2.8(-3.2) mm diam, subterete, the ventral sulcus obscure or very shallow and narrow, only upward along rachis becoming a little excavated below each pair of pulvinules; rachis (7-) 10-33(-40) cm, its longer interfoliolar segments 4-7(-8.5) cm; pulvinules pallid or livid wrinkled, sulcate ventrally (2.8-)3-8(-9) mm; lfts (2-)3-7 pairs, accrescent upward but either the terminal or the penultimate pair largest, these subsymmetrically ovate from broadly or narrowly cuneate base, (7-9.5-21 x (4.5-)5-8.5(-9) cm, (1.6-) 1.8-.8(-3) times as long as wide, at apex obscurely to emphatically acuminate, the acumen itself obtuse or retuse mucronulate, the plane margin delicately nerve-marginate, the tapering midrib immersed or shallowly depressed above, cariniform beneath, giving rise on each side to ±30-60 camptodrome and almost equally strong intercalary secondary veins, these all with the tertiary and reticular venulation finely sharply prominulous on both faces.

Racemes laxly (7-) 15-75-fld, the tapering primary axis 1.5-6.5 dm, that of some lateral axes shorter, all elongating prior to anthesis, then several fls simultaneously expanded and often retaining their ± reflexed petals after both sepals and androecium have fallen; bracts subulate or linear-caudate 2-5 mm, caducous with the similar but shorter bracteoles as the pedicel begins to elongate; pedicels (of fully expanded fls, including the hypanthium) 3-6(-7.5) cm, widely spreading or from geotropic axes refracted and twisted to restore the (actually resupinate) fl to vertical; hypanthium slenderly vase-shaped 2-5.5 mm; sepals early reflexed, thinly herbaceous membranous-margined, greenish, brownish or pink-tinged, puberulent on both faces, scarcely or moderately graduated, the inner ones obovate or oblong-elliptic (6-)6.5-9.5(-11.5) mm; petals clear golden-yellow drying pale yellow delicately brown-veined, subequilong or the vexillum shortest and the abaxial petals longest, the elliptic-oblanceolate or obovate blade cuneately narrowed to a claw 1-2.5 mm, the longest petal (18-)21-32 x (8-) 11—24 mm; androecium glabrous except for dorsally pilosulous fertile anthers, the sigmoid filaments of 3 long stamens (26-)31-43 mm, of 4 fertile antepetalous ones erect linear-attenuate, varying (in 2 pairs) from 5-7 to 11-13 mm, of 3 adaxial stamens 4-13 mm, that of the 2 antesepalous ones curved or coiled at apex, that of the antevexillar one straight; anthers of 3 long stamens elliptic or ovate-elliptic obtuse (3.5-)3.6-4.6 x 2.1-2.5 mm, of 4 fertile antepetalous ones pitched forward, in lateral view gently sigmoid-curved, in dorsal view broadly oblanceolate 4-5.2 x 1.8-2.4 mm, the anthers of 3 adaxial stamens much smaller ±1.2-2.4 mm, sterile or almost so; ovary strigulose, sometimes subglabrous, rarely pilosulous, its stipe 5.5-9 mm, the style 3-4.5(-5) x (0.6-)0.65-0.9(-l) mm, its obliquely antrorse stigmatic cavity 0.15-0.3 mm; ovules (80-)92-122(-151).

Pod pendulous, slowly maturing and long persisting on the tree, narrowly rodshaped terete (strangulated only where ovules abort), when fully fertile 3-6 dm x 1.5-2.3(-2.5) cm, abruptly rounded at both ends, the sutures externally visible but not thickened and fully immersed, the thin fibrous epidermis early atrolivid or black, smooth glabrous and transversely fissured when dry, the woody endocarp 0.5-1 mm thick, the interseminal septa stiffly chartaceous 0.15-0.2 mm thick, the fertile locules ±5 mm long; seeds transverse, turned broadside to the septa embedded in sweet glutinous blackish pulp, this lining the locule when dry with a pitchlike layer and also enveloping the seed with a thin loose envelope, the seed itself biconvexly obovoid-ellipsoid 7.5-10 x 6-7 x 2.5-3 mm, the cas-taneous testa smooth and glossy; x = 14.—Collections: 56.—Fig. 2 (pod).

Native of s.-e. Asia, probably (De Wit, 1955, l.c.) originally in open forest subject to dry monsoon conditions, prized for the beauty of its flowers sometimes used for ritual adornment and for its medicinal pods, long since dispersed throughout the Indian subcontinent, Malesia, Indochina and some islands of Micronesia, thence to tropical and n.-e. subtropical Africa, prior to 1800 established in the West Indies and Mexico; in the Neotropics widely planted in streets, parks and gardens, whence sparingly spontaneous but nowhere extensively naturalized or appearing native, known by spms from s.-e. Mexico through Central America to Colombia, n. Venezuela, Trinidad and the Guianas, in Brazil from cities and botanical gardens only, common in the Greater and many of the Lesser Antilles, cultivated in warm temperate Florida and California, and in Hawaii.—Fl. most abundantly in the dry or cool season, but sporadically throughout the year, the foliage annually renewed and the pods long persisting through slow maturation on the tree, the seeds released only by rotting of the pod on the ground.—Golden Shower Tree, Indian Laburnum, Pudding Pipe Tree, Purging Cassia; Caneficier (French Antilles); cahafistula (Spanish Amer.); canafistula (Brazil).