Citation: F. Mueller, Fragm.Phyt.Aust. 1:6 (1858)

Derivation: mikros (Gr.)--small; karpos (Gr.)--fruit.

Synonymy: Not Applicable

Common name: Manna wattle

Description:
Small, diffuse, rounded, bushy shrubs 1-3 m high with spreading branches often the same as height or more across, or tall erect with a number of stems ascending from the base; branches glabrous, slightly angular, smooth, soon becoming terete; bark reddish-brown, dark grey on mature stems.

Phyllodes linear-oblong or linear lanceolate, oblique, 2-5 cm long, 5-10 mm broad, straight or curved, slightly pubescent when young, soon glabrous, mid-vein prominent or sometimes rather obscure, lateral veins few or almost absent, apex obtuse or notched, with a small recurved mucro; glands small, situated well below the middle of the phyllode on the upper margin. Stipules present or absent at the base of the phyllode, small and setaceous.

Inflorescences simple and axillary, usually twin or in clusters of 3 or 4; flower-heads globular, bright yellow, 20-30-flowered; peduncles slender, 5-12 mm long, usually turning blackish upon drying; flowers 5-merous.

Legumes linear, curved, 3-6 cm long, 3-5 mm broad, biconvex, dark brown, apex usually acute; margins thickened, slightly constricted. Seeds longitudinal in legume; funicle slender, short, aril whitish, large, conical.

Distribution:  Common in the Eyre Peninsula, Yorke Peninsula, Northern and Southern Lofty, Kangaroo Island, Murray and South-Eastern regions. Found in a wide variety of vegetation formations and soil types. Rainfall 250-600 mm. Also N.S.W. and Vic. S.Aust.: EP, NL, MU, YP, SL, SE. Flowering time: August — October.

SA Distribution Map based on current data relating to specimens held in the State Herbarium of South Australia

Biology: No text

Related taxa: Acacia triquetra is very similar to the small-phyllode forms of A. microcarpa and the former is distinguished by the acutely angular branches and fewer flowers per head.

Taxonomic notes: A. microcarpa var. linearis Black was described from material from near Monarto South and has been considered conspecific with A. x grayana Willis which was based on material from western Victoria. However it was suggested by Leach & Whiffin (1978) that all of these are hybrids (or intermediates) of A. calamifolia and A. brachybotrya. Further work is needed to clarify the status of these various taxa.

The species A. microcarpa and its allies are discussed by Maslin (1987) where a map of its distribution is also given. Confusion with A. triquetra and A. acinacea has occurred.

Cultivation: A useful low bushy ornamental species having masses of flowers in spring, suitable for roadside planting and soil stabilisation in near coastal and inland areas. Fast growth rate.

Author: Not yet available

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