Peltophorum dasyrhachis (Miquel) Kurz

Peltophorum dasyrhachis (Miquel) Kurz

Family

Leguminosae

Synonyms

Caesalpinia dasyrhachis Miquel, Peltophorum grande Prain, Peltophorum tonk­inense (Pierre) Gagnep.

Vernacular Names

Ma­laysia

Batai, jemerelang.

English

Peltophorum.

Indone­sia

Soga (Palembang), petaian (Lampung).

Cambodia

Trâse:k.

Laos   

S'a:z kha:m, sa: fang, sa: ph'ang.

Thailand

Nonsi (centra!), arang (north-eastern).

Vietnam

Lim x[ej]t, lim v[af]ng.

Geographical Distributions

Peltophorum da­syrhachis is found in Thailand, Indo-China, Peninsular Malaysia, Sumatra and Borneo. It is also cultivated in many other tropical regions, e.g. in Java.

Description

Peltophorum da­syrhachis is usually a deciduous tree that can grow up to 30 m tall, with a straight trunk and rather diffuse crown. The root system is with a well-developed taproot and a few superficial lateral roots. Its trunk is up to 70 cm in diametre. The bark is up to 10 mm thick and reddish­ brown inside. The young branches are reddish-hairy.

The leaves are bipinnate, with 5-9 pairs of pinnae and 6-16 pairs of leaflets per pinna. The stipules are large, bipartite and with pinnatifid or bipin­natifid branches. The petiole is up to 7 cm long. The rachis is up to 40 cm long. Both petiole and rachis are reddish-pubescent. The leaflets are oblong-ellip­tical, measuring 10-25 mm x 4-10 mm, sessile, acute at base, obtuse or rounded, rounded-emarginate at apex, finely pubescent, nearly hairy, rather glaucous be­low and shiny above.

The inflorescence is an axillary with un­branched raceme and measures 15-30 cm long. The bracts are linear, measure 10-12 mm long and persisting until the flowers open. The pedicel is 1.7-4 cm long. The sepal is deeply 5-lobed. The lobes are ovate, measuring 10-15 mm x 5-6 mm, densely velvety out­side and hairless inside. There are 5 obovate petals which measure 15-25 mm x 10-12 mm, spreading, yellow and hairy towards the base inside. There are 10 free stamens. The filaments are 10-15 mm long and woolly at the base. The anthers are dorsifixed.

The ovary is ses­sile. It is 5 mm long, hairy, 4-8-ovuled and with slender style. The pod is elliptical, sharp-pointed, measuring 10-15 cm x 2--4 cm, flat and dull-brown when ripens but blackish later. It is 4-8-seeded, indehiscent and often hanging in bunches below the leaves. The seed is flat­tened oblongoid, measuring 10-12 mm x 5 mm and transversely positioned. Seedling is with epigeal germination. The hypocotyl is 4-6 cm long. The cotyledons are stalked, 3 ­nerved and smooth.

Ecology / Cultivation

Peltophorum dasyrhachis is found in secondary, deciduous or evergreen forests below 800 m alti­tude with an annual rainfall of 1500-2500 mm. It is mainly found on ultisols. Due to its relatively deep rooting system, it is drought tolerant. Its hairiness and fairly thick bark have been associat­ed with its tolerance of fire.

Line Drawing / Photograph

Peltophorum_dasyrhachis

References

1.       Plant Resources of South-East Asia No.11: Auxiliary plants.