Flora of New Zealand Series

Trees, shrubs or rarely herbs. Lvs either 2-paripinnate with few to numerous paired pinnae along the rachis and each pinna with usually numerous, sessile paired pinnules, or lvs reduced to simple phyllodes; glands present on petiole and rachis; stipules spinescent or membranous, often minute. Infl. a cylindric spike or globose head; spikes or heads axillary, solitary or arranged in simple or compound racemes or apparently terminal panicles; subtending bracts small, usually triangular; subtending bracteoles small, usually linear with expanded deltate apex. Fls small, actinomorphic, (3)-4-5-merous, usually yellow or cream; calyx shallowly or deeply divided; petals usually free, sometimes united at base. Stamens numerous, free, exserted; anthers uniform, versatile. Style filiform; stigma terminal. Pod 2-valved, straight, curved or twisted, dehiscent or indehiscent, few- to many-seeded; seeds with a variously folded and thickened fleshy aril.

c. 700 spp., mainly Australia, a few in the Mascarenes, Madagascar, the Philippines, Taiwan, and the Pacific Is to Hawaii. Naturalised spp. 13.

All of the spp. included here have previously been treated in Acacia Miller. However, Pedley, L., Bot. Jour. Linn. Soc. 92: 219-284 (1986), accepted 3 genera and noted that Racosperma and Senegalia have an origin within the Ingeae independent from that of Acacia sens. strict.

Many spp., including all those which are naturalised, are cultivated in N.Z. as ornamentals, or for shelter and firewood. The common names wattle and acacia are used for many spp. Many wattles are considered poisonous (Connor 1977).

Descriptions of lvs apply to those of mature trees. Lvs of seedlings of 2-pinnate acacias and lvs subtending infls are often reduced in pinna and pinnule number. Seedlings lvs are usually 2-pinnate even in spp. which have adult lvs reduced to phyllodes. The small fls are conspicuous because of their aggregation into dense infls.

Fig. 70. Seeds and arils of Racosperma. A R. longifolium; B R. melanoxylon. © All rights reserved. [Image: 4X5X]