Prairie acacia. Timbre. Fernleaf Acacia
Acacia angustissima

Family: Fabaceae

What it is like

A. angustissima is native to North America (Mexico and southern United States), Central America and South America (Venezuela, Colombia, Peru, Bolivia and Argentina) (Rico Arce and Bachman, 2006). It is one of the acacias most widely distributed in the Neotropics (Cook et al., 2005). Outside its native range it is reported for the Caribbean, Asia, Africa and Oceania (see distribution table for details). Although it may not grow into a large tree, it can be extremely valuable for use as pioneer species for rejuvenating degraded lands, and as a nurse crop for more valuable tree species. Used as a nitrogen fixer. Acacia angustissima hirta (dwarf prairie acacia) is a smaller version growing to 1m (3ft) high and 2m (6ft) wide. Both Acacia angustissima and Acacia angustissima hirta have a clumping habit. May also known as Acaciella angustissima.

Acacia angustissima is an evergreen Tree growing to 5 m (16ft) by 3 m (9ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 7. It can fix Nitrogen. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid and neutral soils and can grow in very acid soils. It cannot grow in the shade. It prefers dry or moist soil and can tolerate drought.

Height (m): 5

Where it is found

It is a subtropical plant. Hillsides, rock slopes, summits and in grassland with other shrubs, often in deciduous or semi-deciduous forest. Mostly on rather dry, often rocky, brushy slopes or in thin forest, frequent in pine-oak forest, sometimes in hedges, to 2,700 m.

C. America - Panama, north to Mexico and southern N. America.

Conservation Status: This taxon has not yet been assessed

Countries/locations it is found in

Africa, Belize, Central America, Colombia, Costa Rica, East Africa, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, North America, Panama, South America, USA, Zimbabwe,

How it is used

Food

Rating: 2

The seedpods have been used for food by local peoples. The bitter astringent bark is used in Mexico for precipitating mucilaginous matter and inducing fermentation in the making of alcoholic drinks.

Inner bark: the bark that is found just beneath the tough outer bark of trees and shrubs.

Seedpod: things such as Okra, French and Runner beans.

Medicine

Rating: 3

Acacia angustissima is an important medicinal species for the Tzotzil and Tzeltal Maya Indians in Mexico. They rank it the 4th most important species in the cure of bloody diarrhoea and 7th in the treatment of mucoid diarrhoea. It is also used as a cure for toothache, rheumatism and skin lesions, and is reported to inhibit growth in malignant tumours. Tests also show that it possesses a mild antimicrobial effect on Escherichia coli and Staphylococcus aureus. The medical activity will at least be partly due to the astringent tannins found in the plant. The bark of all Acacia species contains greater or lesser quantities of tannins and are astringent. Astringents are often used medicinally - taken internally, for example. they are used in the treatment of diarrhoea and dysentery, and can also be helpful in cases of internal bleeding. Applied externally, often as a wash, they are used to treat wounds and other skin problems, haemorrhoids, perspiring feet, some eye problems, as a mouth wash etc. Many Acacia trees also yield greater or lesser quantities of a gum from the trunk and stems. This is sometimes taken internally in the treatment of diarrhoea and haemorrhoids.

Dysentery: Used in treating dysentery - an infection of the intestines that causes diarrhoea containing blood or mucus.

Other

Rating: 4

Agroforestry Uses: Although it may not grow into a large tree, it can be extremely valuable for use as pioneer species for rejuvenating degraded lands, and as a nurse crop for more valuable tree species. Its potential as a mulch producer has come into question, because of the presence of secondary compounds that bind the nitrogen and result in low quality (slowly decomposing) prunings. This may mean that the mulch is a poor nitrogen source for the present crop, but it may have greater residual effects that could benefit the subsequent crop, or be a good nitrogen source to help build up organic matter in the soil. These long-term benefits could outweigh the initial low nutrient return to the soil over a number of years. Slowly decomposing prunings may have value for suppressing weed growth in associated crops. Other Uses: Tannin is obtained from the bark. Bark harvested for its tannins should only be taken from mature stems, and only when the sap is rising at the beginning of the growing season - which is when the tannin content is highest and the bark is most easily removed from the wood. Carbon Farming - Industrial Crop: biomass. Agroforestry Services: nitrogen, alley crop.

Biomass: Provides a large quantity of plant material that can be converted into fuel etc.

Mulch: Used for covering the ground to conserve the nutrients in the soil.

Pioneer: Plants, usually trees and shrubs, that can be used to reforest land.

Soil reclamation: Plants that can be grown in such circumstances an the spoil tips of mines in order to restore fertility.

Tannin: An astringent substance obtaied from plants, it is used medicinally, as a dye and mordant, stabilizer in pesticide etc.

Agroforestry Services: Alley crop: Integrates annual crops with rows of perennials.

Agroforestry Services: Nitrogen: Plants that contribute to nitrogen fixation include the legume family – Fabaceae.

Industrial Crop: Biomass: Three broad categories: bamboos, resprouting woody plants, and giant grasses. uses include: protein, materials (paper, building materials, fibers, biochar etc.), chemicals (biobased chemicals), energy - biofuels

Management: Coppice: Cut to the ground repeatedly - resprouting vigorously. Non-destructive management systems maintaining the soil organic carbon.

Management: Standard: Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.

Regional Crop: These crops have been domesticated and cultivated regionally but have not been adopted elsewhere and are typically not traded globally, Examples in this broad category include perennial cottons and many nuts and staple fruits.

Agroforestry Services: Alley crop: Integrates annual crops with rows of perennials.

Agroforestry Services: Nitrogen: Plants that contribute to nitrogen fixation include the legume family – Fabaceae.

Industrial Crop: Biomass: Three broad categories: bamboos, resprouting woody plants, and giant grasses. uses include: protein, materials (paper, building materials, fibers, biochar etc.), chemicals (biobased chemicals), energy - biofuels

Management: Coppice: Cut to the ground repeatedly - resprouting vigorously. Non-destructive management systems maintaining the soil organic carbon.

Management: Standard: Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.

Regional Crop: These crops have been domesticated and cultivated regionally but have not been adopted elsewhere and are typically not traded globally, Examples in this broad category include perennial cottons and many nuts and staple fruits.

Carbon Farming: Plants that can be a critical part of the solution to climate problems. The Carbon Farming Solution - Eric Toensmeier.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

How it is grown

Acacia angustissima is a versatile plant that can grow from the warm temperate zone to the tropical zone. It succeeds at elevations from sea level to 2,600 metres, tolerating a mean annual temperature in the range of 5 - 30°c and a mean annual rainfall in the range 895 - 2,870mm. It can tolerate quite cold climates with occasional temperatures falling below freezing. Grows best in a sunny position. Grows well in free-draining, acidic, infertile soils. It is adapted to a wide range of soils including vertisols of slightly alkaline pH. A very drought-tolerant plant, possibly due to its substantial taproot. It can retain its green foliage in dry seasons that can be as long as 8 months. Acacia angustissima is fast-growing, quick to mature and a prolific seed producer. It flowers throughout the year in its natural range. This ability to grow quickly and reproduce when young has resulted in the plant becoming weedy and forming thickets, especially along roadsides and in sandy soil in pastures in its native range. This weed potential has created concern among some researchers about the advisability of its use in agroforestry or agricultural systems. The plant responds well to regular cutting and to coppicing. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby. When introducing A. Angustissima into a new area it may be necessary to inoculate with an appropriate Rhizobium before planting. Carbon Farming - Cultivation: regional crop. Management: standard, coppice. For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. The plant growth habit is multistemmed with multiple stems from the crown.

Propagating it: Seed - germinates best when soaked for 12 hours in cold water prior to sowing. The standard seed treatment for Acacia species (pre-soaking the seed in warm water for 12 hours) results in inferior germination. Scarifying the seed by scratching or nicking the round end of each seed with a file, knife or nail clipper (without damaging the cotyledon) before sowing has also been suggested. Fernleaf acacia seems to fare better when grown from transplanted seedlings than from direct seeding. If it is to be directly seeded, then it is important not to sow too deeply. The seeds should be sown on the surface of cultivated soil and covered with a layer of soil equal to the width of the seed.

Best place to grow:

Habit: Tree

Hardiness: 7-10

Growth: Fast

Soil: Light (sandy), medium, heavy (clay)

Shade: No shade

Moisture: Dry, moist

Things to keep in mind

Especially in times of drought, many Acacia species can concentrate high levels of the toxin Hydrogen cyanide in their foliage, making them dangerous for herbivores to eat.

Acacia angustissima is fast-growing, quick to mature and a prolific seed producer. This ability to grow quickly and reproduce when young has resulted in the plant becoming weedy and forming thickets, especially along roadsides and in sandy soil in pastures in its native range. This weed potential has created concern among some researchers about the advisability of its use in agroforestry or agricultural systems. The plant responds well to regular cutting and to coppicing.

Its other names

Local names

Carboncillo, Timbe, Timbre, Whiteball acacia, Prairie acacia, White ball acacia, Ocpatl, Palo de Pulque

Synonyms

Acaciella angustissima (Mill.) Britton & Rose is a synonym of Acacia angustissima (Mill.) Kuntze. Acacia angulosa Bertol.;Acacia elegans M. Martens & Galeoti;Acacia filicina Willd.;Acacia filicioides (Cav.) Trel.;Acacia glabrata Schldl.;Acacia insignis M. Martens & Galeoti;Acacia pittieriana Standley;Acaciella angulosa (Bertol.) Britton & Rose;Acaciella angistissima (Miller) Britton & Rose;Acaciella costariciensis Britton & Rose;Acaciella holtonii Britton & Killip;Acaciella martensis Britton & Killip;Acaciella rensonii Britton & Rose;Acaciella santanderensis Britton & Killip;Mimosa angustissima Miller;Mimosa filicioides Cav.;Mimosa ptericina Poiret;