WATTLE

Acacias of Australia

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Acacia lapidosa Maslin

Common Name

Mt Magnet Rock Wattle

Family

Fabaceae

Distribution

Known only from a few populations in the vicinity of Mt Magnet, W.A.

Description

Erect, ±obconic or rounded, multi-stemmed, ±gnarled shrubs 1–3.5 m tall, main stems and branches somewhat contorted. Branchlets glabrous except sparsely sericeous at the extremities. Phyllodes narrowly linear, straight to shallowly incurved or shallowly sigmoid, erect, glabrous or sparsely silvery-white appressed-hairy, flat to compressed or sub-terete, (5–) 6–9.5 cm long, 1–1.5 mm wide, delicately acuminate by ±shallowly curved, innocuous tips; finely multi-nerved, margins occasionally resinous; gland basal. Flowers not seen. Peduncles (fruiting) 3–5 mm long. Pods narrowly oblong to broadly linear, 4–13 cm long, 7–9.5 mm wide, rounded over seeds, firmly coriaceous-crustaceous to ±sub-woody, greyish mid-brown to very dark brown (almost black), sparsely to moderately appressed hairy; marginal nerve not thickened. Seeds longitudinal, obloid to ellipsoid, large (mostly 8–10 x 5–7.5 mm), shallowly concave at centre, dark brown to black; aril small and terminal.

Phenology

Mature pods: early June. and late Sept.–Oct.

Habitat

Grows skeletal soils on rocky hills and plains in open Acacia-dominated shrubland.

Notes

Related to A. umbraculiformis which is readily distinguished by its characteristically wide-spreading, falcately recurved, broader phyllodes (mostly 3-7.5 mm wide) and its arborescent habit. These two species are at least sometimes sympatric and occasional hybrids are suspected; see B.R.Maslin, Nuytsia 24: 202 (2014) for notes.

Conservation

Acacia lapidosa is listed as Priority One under Department of Parks and Wildlife Conservation Codes for Western Australian Flora.

FOA Reference

Flora of Australia Project

Author

B.R. Maslin