Botanical Name: Acacia mearnsii
Synonyms: Acacia mearnsii de Wild. syn. Acacia mollissima sensu auct. mult., non Willd.: Acacia decurrens (Wendl.) Willd. var, mollis Lindl. Albizia mearnsii De Wild. Racosperma mearnsii (De Wild.)
Common Name: Black wattle, Acacia-negra (Portuguese), Australian acacia, Australische Akazie (German), Swartwattel (Afrikaans), Uwatela (Zulu), Blue passion flower
Altitude: up to 2200 ft
Seed collection period: November
Seed longevity: 1-2 years
Acacia mearnsii is a small to large, evergreen, single-stemmed or multibranched tree, 6-25 m high, with a straight trunk, growing to 50 cm in diameter; crown low, spreading, rounded; spines absent; bark brownishblack, hard and fissured; twigs angled, grey, densely hairy, tinged with yellow when young. Trees in their natural habitat have a spreading, rounded crown, but are erect and slender when crowded in plantations. Leaves dark green, alternate, feathery, with very soft hair, binnately compound.
A. mearnsii is a hermaphrodite and flowers profusely in the winter. Trees begin to yield fertile seed from the age of 5 years, giving good annual crops. The minute, fragrant flowers are self-fertile, but cross-pollination occurs. Bees are the main pollinators. Pods mature in 14 months, and gravity or propulsion from drying dehiscent pods initiates seed dispersal. In Nigrils, India, A. mearnsii flowers mainly in January-February and sporadically all year round; pods in April-May. In Australia, flowering takes place between October and December and fruits mature in 12-14 months.