Acacia tumida F. Muell. ex Benth.

Leguminosae

Common names

Pindan wattle

Description

Multi-stemmed shrub 2-3 m high or a small tree 5-15 m with a well developed canopy. Bark is soft and more or less glossy, occasionally fissurate. Habit is very variable erect to drooping. Main branches have a pruinose bark ; twigs are either glabrous, pruinose or hairy. Phyllodes are greyish-green or glaucous, occasionally pruinose, falcate or sub-falcate 7-22 cm long x 10-50 mm wide, glabrous in the mature, occasionally hairy in the young, with 5-11 longitudinal nerves, 3 of them conspicuously protruding and 3 or 4 less so, many secondary nerves are obscurely marked more or less anastomosing. Flowers are occasionally very fragrant, golden-yellow clustered in spikes 2.7-5 cm long borne by glabrous peduncles 5-10 mm long. Inflorescences are elongated in open racemes. Pods large, up to 16 cm long x 5-10 mm wide, hard and woody or sub-woody, pruinose, cylindrical or more or less compressed , linear to slightly curved, more or less corrugated. Seeds bright, brown to black, 5-8 mm x 4-4 mm, with a cream-colored aril. Life span is short < 10 years.

Water

It is found in the arid and humid ecozones (125-1000 mm MAR).

Soil

Found on soils with an acidic to alkaline reaction, prefers sandy habitats.

Distribution

A. tumida is a tropical semi-arid zone species of North Australia (Western Austrlia, Northern Territory and Queensland)

Propagation

Propagation occurs by seeds, ability to coppice variable, ability to suckering seems to depend on the provenance.

Variability

Taxonomically allied taxa are A. monticola, A. eriopoda, A. trachycarpa with which it seems to readily hybridize.

Products & uses

It provides good quality firewood, in Niger early growth was very fast (2.4 m in 14 months). Young pods are browsed, but phyllodes are hardly consumed by stock neither in Australia nor in the Sahel. Windbreak : A. tumida is very efficient as a low windbreak as in Thiénaba, Senegal, under a MAR of 450 mm. It could therefore be associated with slower growing species such as Faidherbia albida, A. holosericea and A. trachycarpa, however, seem to be more appropriate than A. tumida for the purpose of sand binding. As most Australian acacias seeds are nutritious for humans they can therefore constitute a useful food resource in arid lands.

Links for the genus:

• The WattleWeb: Acacias from A-Z
• Seed treatment and inoculation: Instructions for acacias and other NFT (Nitrogen Fixing Trees)
• Sustainable livestock production: Indigenous knowledge in utilization of local trees and shrubs in central Tanzania

References

Turnbull 1986 ; Thompson 1992 ; Harwood 1993 ; Gunn & Vercoe 1993 ; Maslin & Thompson 1992 ; Maslin & McDonald 1996 ; Hamel 1980 ; Dommergues et al. 1999.