Caesalpinia sappan

Author: Linnaeus

Morphological description (sappan Caesalp Lf/fl FT15 )
Small tree or shrub , up to 10 m tall; branchlets usually with recurved prickles, rarely unarmed. Stipules 3–4 mm, caducous.

Leaves: bipinnate; rachis 25–40 cm; pinnae 9–14 pairs. Leaflets 10–20 pairs per pinna, opposite, sessile or subsessile, oblong, 10–25 by 3–11 mm; base obliquely truncate; apex retuse or rounded; glabrous or sparsely shortly hairy.

Inflorescences supra-axillary and terminal, paniculate, 10–40 cm long; bracts 5–12 by 2–5 mm hairy, caducous; pedicels 15–20 mm, articulated 1–2 mm below the top.

Flower yellow, glabrous, often punctate. Hypanthium c. 2 mm deep and 6–8 mm wide. Sepals ciliate, the lower one c. 10 by 4 mm, the others c. 7 by 4 mm. Petals 9–11.5 by 6–10 mm, clawed (claw up to 5 mm long). Stamens exserted; filaments c. 15 mm; anthers c. 1.5 mm long, glabrous. Pistil c. 18 mm long, pubescent; ovary c. 4 by 1.5 mm, 3–6-ovuled; style c. 14 mm; stigma c. 0.5 mm in diameter, ciliate.

Pods (pedicels up to 20 mm), oblong to asymmetrically elliptic, 6–10 by 3–4 cm; base rounded; apex truncate; beaked, 2–4-seeded (sappan Caesalp pod Reinw9/4 ).

Seeds ellipsoid, 15–18 by 8–11 mm, black (sappan Caesalpinia seed 256048 ).

Origin unknown. Cultivated in S & SE Asia, Malesia , Africa, and America. Sometimes escaped from cultivation.

The wood ( ‘sappanwood’ ) was a major world source of red dye till the end of the 19th century. See Burkill (1935: 390), Heyne (1950: 753), and Zerrudo (1991: 60).