Acacia undoolyana G.J.Leach
WATTLE
Acacias of Australia
Common Name
Sickle-leaf Wattle, Undoolya Wattle
Family
Fabaceae
Distribution
Restricted to the East MacDonnell Ra., N.T., from N’Dhala Gorge (c. 65 km E of Alice Springs), Kadaicha Ra. and 25 km SW of Trephina Gorge.
Description
Shrub or tree 1–15 m high. Bark flaky or fissured, greyish brown. Branchlets terete, appressed pubescent or glabrous, rarely lightly pruinose, obscurely ribbed. New shoots silvery or very pale yellow sericeous. Phyllodes narrowly elliptic, normally markedly falcate, 15–22 cm long, (4–) 6–12 (–16) mm wide, with conspicuous yellowish margins, coriaceous, stiff, silvery-velvety when young, later sparsely pubescent and with dense white scurfy bloom; finely multistriate, with 1–3 nerves more prominent, not visibly anastomosing; gland basal, inconspicuous. Inflorescences short, (1–) 2 (–4)-branched racemes 1–10 (–15) mm long which often grow out; peduncles 3–6 mm long, densely appressed pubescent; spikes, 1.3–3.5 (–5) cm long, dense, bright yellow. Flowers 5-merous; calyx 0.7–1 mm long, dissected to 1/4–1/5, pubescent especially on ribs, with obtuse lobes; corolla twice as long as calyx, dissected to 1/2, glabrous. Pods linear, raised over and constricted between seeds, 5–11 cm long, 2–3 mm wide, sparsely pubescent. Seeds longitudinal, oblong, 3–4.5 mm long, brown.
Phenology
Flowers Aug. & Sept.; fruits Sept. & Oct.
Habitat
Grows on steep rocky slopes with skeletal soils or at the base of sandstone gullies.
Specimens
N.T.: N’dala [N’dhala] Gorge, 15 Oct. 1966, A.C.Beauglehole. (DNA); Ndala [N’dhala] Gorge Scenic Reserve, 16 Aug. 1987, L.D.Meredith et al. (CANB n.v., MEL n.v., NSW); Kadaicha Ra., A.Soos 24 to 27 (DNA).
Notes
Closely allied to A. macdonnellensis, being distinguished by its strongly falcate phyllodes which are longer (15–22 cm), broader (6–12 mm) and silvery when fresh. It is also related to A. ammobia which has glabrous peduncles, mostly straight phyllodes and occurs on sand dunes.
FOA Reference
Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia
Author
Dr M.D.Tindale and Dr P.G.Kodela with the assistance of M.Bedward, S.J.Davies, C.Herscovitch, D.A.Keith and/or D.A.Morrison
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