Cassia fistula
Sp. Pl. 1: 377. 1753.
Trees to 20 m. Leaves bicolored, papery; petiole 40–90 mm; leaflets 10–25 pairs and blades small, or 3–10 pairs and blades larger, subsymmetrically ovate, apex rounded to apiculate or retuse. Racemes pendent; bracteoles caducous at anthesis (distal to base). Pedicels laterally compressed, 30–75 mm. Flowers: calyx reflexed at anthesis, greenish or brownish; petals to 21–32 mm, claw 1–2.5 mm; filaments 5–13 or 26–43 mm; anthers of shorter stamens strongly connate, dehiscing by basal pore, of longer stamens by lateral slits and basal pore; ovary incurved, linear, slightly hairy. Legumes pendulous, dark brown-black, 300–600 × 15–25 mm. Seeds transverse, biconvex, embedded in glutinous, blackish pulp, 7.5–10 × 6–7 × 2.5–3 mm.
Phenology: Flowering summer–fall.
Habitat: Open, dry deciduous forests.
Elevation: 0–100 m.
Distribution
Introduced; Fla., se Asia, introduced also in s Mexico, West Indies, Central America, South America, Africa, Indian Ocean Islands (Madagascar), Australia.
Discussion
Cassia fistula has long been used for ritual adornment and, especially, for the laxative and purgative properties of its fruits. The plant is used locally also as a remedy for anthrax, blood poisoning, dysentery, malaria, and kidney stones, as a vermifuge, and to purify wounds and ulcers (C. H. Bosch 2008).
Of the other species cultivated in North America, only Cassia leptophylla has yellow flowers; it differs from C. fistula in its erect inflorescences and greater number of leaflet pairs. In contrast, C. grandis, C. javanica, and C. roxburghii have pink flowers (and also pink-whitish in C. javanica). Bracts fall off before anthesis in the former species; they are persistent in the latter two. Cassia roxburghii differs from the similar C. javanica in its much shorter pedicels (1–2 cm) and smaller leaflets (20–40 mm) (H. S. Irwin and R. C. Barneby 1982).
Selected References
None.