Acacia decurrens (Bekele-Tesemma, 2007)
| Acacia decurrens (Bekele-Tesemma, 2007) |
Acacia decurrens (Racosperma decurrens) (Fabaceae, S.E. Australia)
habit
flowers
Common names
- English: Green wattle, King wattle, Sydney black wattle
- Agewgna: Yeferenj Tsatsi
- Amargna: Akacha, Mimosa
Ecology
This species grows naturally in lower mountain valleys south of Sydney, Australia and has been widely introduced elsewhere. In Ethiopia, it is cultivated in Wolega and Shoa regions above 1,000 m. It grows well in Moist and Wet Weyna Dega and Dega agroclimatic zones, 1,600–2,500 m.
Uses
Firewood, charcoal, poles, posts, forage (pods), bee forage, shade, ornamental, nitrogen fixation, soil conservation, windbreak, tannin (bark), live fence.
Description
A beautiful tree or shrub with strong upright growth, 6–12 m or more, the young green branchlets quite angular with wing-like ridges.
- LEAVES: Feathery, compound with 8–15 pairs of pinnae and very many narrow leaflets 6–12 mm long.
- FLOWERS: Crowded in bright goldenyellow heads.
- FRUIT: Thin pods, brown–dark brown, breaking open one side only, jointed but not so much narrowed between seeds as A. mearnsii.
Propagation
Seedlings, direct sowing at site.
Seed
40,000–70,000 seed per kg; 50–70% germination in 15–20 days.
- Treatment: Immerse in boiling water, allow to cool and soak for 24 hours.
- Storage: Will store many years in a cool dry place.
Management
Seedlings should spend 7–8 months in the nursery before planting out. Will regenerate through coppicing and also by seeds germinating naturally after exposure to light fire.
Remarks
The species is closely related to, and often confused with, A. mearnsii and A. dealbata (blue wattle). Although the tannin from the bark is of good quality, special processes are needed to remove undesirable colouring substances. This plant may become a weed, spreading rapidly by seed in good conditions. In Ethiopian conditions, it has great potential for poles and firewood. Best grown in woodlots and can be used to stabilize soil.
