Acacia tortilis (Bekele-Tesemma, 2007)
| Acacia tortilis (Bekele-Tesemma, 2007) |
Acacia tortilis (Fabaceae, indigenous)
habit
habit
leaf, flowers, fruits
Common names
- English: Umbrella thorn
- Afargna: Behbey
- Amargna: Deweni grar
- Borenagna: Dadach
- Gamogna: Shera
- Oromugna: Lotoba, Tedecha
- Sahogna: Tsi
- Somaligna: Abak, Akab, Kura, Ora, Timad
- Tigrigna: Akiba, Aqba
Ecology
A common acacia in most of dry Africa from North and West Africa to South Africa. Widespread in Dry Bereha and Dry and Moist Kolla and Weyna Dega agroclimatic zones of the Afar plain, Bale, Arsi, Harerge, Shoa, western Welo and western Tigray, 300–1,900 m. Favours alkaline soils and can grow in shallow soils. It produces enormous deep roots that penetrate a wide area to collect water.
Uses
Firewood, charcoal, timber, poles, posts, fodder (shoots, leaves, pods), bee forage, shade (livestock), nitrogen fixation, soil conservation, fibre (bark), fences (cut branches).
Description
A characteristic tree of drylands, 4–21 m, the crown layered, flat and spreading or rounded, sometimes a shrub.
- BARK: Grey‑brown-black and fissured when mature.
- THORNS: Two kinds: small hooked and long, straight white, sometimes mixed pairs all on one stem.
- LEAVES: 2–10 pairs of pinnae on a short stalk only 2–4 cm.
- FLOWERS: Fragrant, cream, in round heads.
- FRUIT: pale-yellow‑brown pods, each containing up to 10 brown seeds, hang in dense bunches spirally twisted, sometimes in rings.
Propagation
Seedlings, wildings.
Seed
Slow germination, low germination rate. 12,000–31,000 seed per kg. Beetle infestation often lowers germination rate.
- Treatment: Seed is very hard. Pour boiling water over seed, allow to cool and soak for 24 hours.
- Storage: Seed can be stored for a very long period without losing viability if insect damage can be prevented.
Management
Slow growing but if well managed, it grows relatively fast in dry sandy soils. Protect young plants from goats. Lopping.
Remarks
Often indicates the tree limit into desert areas. It can be left to grow on pasture or crop land. The pods are an important source of fodder in the semi-desert areas of Africa.
