Peltophorum, Soga
Peltophorum dasyrhachis
Family: Fabaceae
What it is like
A natural pioneer species, Peltophorum dasyrhachis is a deciduous flowering tree reaching a height of up to 30m. The bole is straight and around 50 - 90cm in diameter. The crown is open and diffuse. It has drooping racemes comprised of yellow flowers. The tree is commonly grown across Southeast Asia and in Africa. The plant has high content of polyphenolic substances, hence decomposition rate of its leaf litter is slow. As a result, weed growth is suppressed and soil erosion is minimized. Young plants are shade tolerant while established plants are drought tolerant. The plant is also tolerant to fire due to its thick and hairy bark. The bark is used medicinally in the treatment of coughs. The wood is heavy and durable but prone to insect and termite attacks. It is used for planks, furniture, boards, posts, and as firewood.
Peltophorum dasyrhachis is a deciduous Tree growing to 25 m (82ft) by 25 m (82ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 10. It can fix Nitrogen. Suitable for: medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.
Height (m): 25
Where it is found
Secondary, deciduous or evergreen forest, usually occupying the upper storey of secondary forest, and large openings in the forest or at forest margins. Usually found mixed with other broad-leaved species in evergreen broad-leaved forest.
Southeast Asia - Thailand, Malaysia, Indonesia, Cambodia, Laos, Vietnam.
Conservation Status: This taxon has not yet been assessed
Countries/locations it is found in
How it is used
Food
Rating: 0
Medicine
Rating: 2
The bark is used in an infusion to treat coughs.
Antitussive: Prevents or relieves coughing.
Other
Rating: 4
Agroforestry Uses: The tree is a natural pioneer species, quickly invading open areas in the forests and abandoned agricultural land. Its use in the reclamation of Imperata cylindrica grasslands is being tested; in Indonesia and Malaysia, young trees planted in tall Imperata grassland and left untended after planting remained alive, but grew slowly. Due to a fairly high content of polyphenolic substances, decomposition of the leaf litter is slow, allowing a humus layer to build up in the soil. This slow rate of decomposition reduces soil erosion and also contributes to the suppression of weeds. Seeds of Imperata cylindrica hardly germinate in soil covered by the leaves. The tree has been used as a shade tree, mainly in coffee plantations. It is sometimes maintained after bush fallow as a shade tree for fruit trees and for its role in soil improvement. When unpruned, it provides a rather dense shade to control weeds during fallow periods, and can be managed in hedges without too much shading of inter-row crops. Because its growth rate is slower than that of Leucaena leucocephala and Gliricidia sepium, it requires less frequent pruning. Plants can be pruned to form a dense hedge. Other Uses The heartwood is red-yellow to brownish; it is distinctly demarcated from the white-grey sapwood. The wood is heavy, brittle, rather durable though attacked by termites and boring insects. Another report says that it is termite resistent. It is used locally for planks in house-building, but is of little market value. The wood is utilized for the production of furniture, boards, posts, and wood pavement as well as in the building of houses and vehicles. The wood is used for fuel.
Fuel: Usually wood, plant materials that have been mentioned as being a good fuel.
Furniture: A few miscellaneous uses that do not fit easily into other headings.
Hedge: Plants that can be grown as hedges.
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.
Soil stabilization: Plants that can be grown in places such as sand dunes in order to prevent erosion by wind, water or other agents.
Wood: A list of the trees and shrubs that are noted for having useful wood.
Hedge: Hedge
Nitrogen Fixer: Plants that fix nitrogen in the soil
How it is grown
A plant of the moist tropics, where it is usually found at elevations from sea level up to 1,000 metres. It grows best in areas with a mean annual rainfall in the range 700 - 2,500mm and a dry season of 1 - 3 months, with a mean annual temperature of 20 - 25°c and the average temperature of the coldest month is not lower than 15°c. Young plants are shade tolerant but the plant requires a sunny position as it grows larger. In the wild, the tree grows on many reddish yellow feralit soils on mica schist, gneiss, reddish basalt, sedimentary soil.. Due to its relatively deep rooting system, established plants are drought tolerant. The tree has a fairly thick bark and is hairy, helping it to be fairly tolerant of fire. The seed germinates in abundance after a bush fire. The trees can be pruned quite severely and usually resprout abundantly. The root system comprises a well-developed taproot and a few superficial lateral roots. 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.
Propagating it: Seed - it can store for at least 2 years with little loss of viability. The seed will benefit from presoaking in warm water prior to sowing. Cuttings.
Best place to grow:
Habit: Tree
Hardiness: 10-12
Growth: Fast
Soil: Medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist
Things to keep in mind
Its other names
Local names
soga, petaian - Indonesian; saph'ang, sa f'ang - Sino-Tibetan/Lao; jemerelang, batai - Malay; nonsi, arang - Thai.
Synonyms
Baryxylum dasyrhachis (Miq.) Pierre Caesalpinia dasyrhachis Miq. Peltophorum grande Prain Peltophoru