Bixa L.

Bixaceae, H. Wild. Flora Zambesiaca 1:1. 1960

Note

Characters of the family.

Timothy M. A. Utteridge and Laura V. S. Jennings (2022). Trees of New Guinea. Kew Publishing. Royal Botanic Gardens, Kew

Distribution

Bixa is native to the Neotropics, but Bixa orellana L. is widely cultivated and naturalised throughout the tropics, including in New Guinea.

Morphology General Habit

Evergreen trees and shrubs to 10 m tall. Latex usually present, reddish

Morphology General Indumentum

Indumentum of reddish peltate scales

Morphology Leaves Stipules

Stipules present, caducous

Morphology Leaves

Leaves alternate, petiole often thickened at the base and apex, chartaceous, ovate, base cordate, margin entire, apex acuminate. Inflorescences terminal, thyrsoid

Morphology Reproductive morphology Flowers

Flowers bisexual, actinomorphic, showy, 5-merous; calyx lobes free, caducous; petals free, white or pink, alternating with calyx lobes; stamens numerous, free, anthers dithecal, horseshoe-shaped, dehsicing by apical slits; ovary superior, sessile, carpels 2, 1-locular, placentation parietal, ovules numerous, style simple

Morphology Reproductive morphology Fruits

Fruit a 2-valved loculicidal capsule, often laterally compressed, exocarp usually with bristly hairs

Morphology Reproductive morphology Seeds

Seeds numerous, obovoid, covered with a red sarcotesta.

Ecology

Bixa is cultivated in New Guinea for the red dye extracted from the seeds and is therefore usually associated with villages and gardens, but is also naturalised in open areas like forest margins. It has been collected from elevations up to 1200 m.

Recognition

It is very distinctive on account of the red, bristly fruits, but can also be recognised by the long petioles which are thickened at both ends, the cordate leaf base and the 5-merous, showy flowers with white or pink petals and numerous stamens.