Caesalpinia spinosa (Mol.) Ktz.

Caesalpinia spinosa is a shrub or small tree up to 5 m high with reflexed prickles along its spreading spinose grey-barked densely leafy branches. Leaves bipinnate, smooth or with sparse, short prickles; pinnae 2-3 pairs, often 10 mm long, with about 8 pairs of subsessile, firm, reticulate-veined, oblong-elliptic, glabrous leaflets, oblique at base, rounded at apex, about 2.5 cm long, 1 cm broad. Flowers reddish-yellow, in narrow racemes 8-12 cm long; pedicels puberulent, 5 mm long, auriculate below the short calyx tube; larger calyx segments serrulate, about 6 mm long, the petals less than twice as long, about as long as the stamens. Pods red, flat, 10 cm long, 2.5 cm broad, 4-7 seeded. Seeds large, round and black at maturity. The generic name is after A. Caesalpini, 1519-1603, Italian physician and botanist. The specific epithet refers to the fact that it bears prickles.

Tara prefers soils with pH 6.8-7.5.

In South America C. spinosa grows in the forests and semi desert areas of the Interandine region, along the higher cooler inner slopes of both Cordilleras of Ecuador. Similar localities in North Africa and elsewhere are preferred ranging from warm temperate through tropical very dry to tropical wet forest zones.

C. spinosa is domesticated in its native range and has a long history of cultivation in North Africa, notably in Morocco and also in tropical East Africa.

Propagation is by seed. Seedlings are transplanted when 10 - 15 cm tall.

Wild trees are subjected to simple pruning operations as most seed is harvested from them.

Seed storage behaviour is orthodox. Seed should be pretreated to break the hard seed coat.

Boundary or barrier or support: C. spinosa is sometimes grown as a live fence in Peru.

Fodder: Seed germ (38 % C. spinosa seed weight) may be used as a source of protein in animal feeds once separated from the hull and endosperm. Timber: The wood is durable. Gum or resin: Seed endosperm (22 % seed weight) yields gum of commercial value. It is a white to yellowish powder and consists chiefly of galactomannan-type polysaccharides. C. spinosa gum is used as a thickening agent and stabilizer in the food industry. Tannin or dyestuff: C. spinosa pods contain 50% tannin, about twice as much as sumac (Rhus). The high content of hydrolysable tan has made it interesting for the extraction of gallic acid and ink manufacturing. The tannin is used on leather. Poison: The pods have high tannin content and may be lethal if consumed in large quantities by animals. Medicine: The powder within pods is used as eyewash.