Abroma augusta (L.) L.f.
Abroma fastuosum Jacq., Theobroma augusta L., Abroma mollis DC.
|English||Devil's cotton, perennial Indian hemp, abroma.|
Kapasan (Javanese), kaworo (Sundanese), rebong pengayoh (Lampung).
|Philippines||Anabo (Ibanag, Ilokano, Tinggian, Tagalog, Bisaya), ambong (Tagalog), pakalkal (Pampango).|
|Thailand||Thian dam (Centra), thian dam luang (Chiang Mai).|
Chi tai m[ef]o, b[oo]ng v[af]ng.
Abrome, abrome royal.
Abroma augusta is distributed from India, throughout Southeast Asia to southern China, the Solomon Islands and northern Australia. It is sometimes cultivated in India and New Guinea and experimental plantings have been set up in the Philippines and Africa (Uganda, Democratic Republic of Congo).
Abroma augusta is an erect shrub or small tree that can grow up to 2-4 m tall, normally branching at the height of 1-2 m and is often multi-stemmed from the base. The stem and branches are with tenacious bark, which is smooth or armed with prickles. All parts are with prickly-pointed, irritating, stellate hairs and sometimes with glandular hairs. The orthotropic branches usually remain vegetative while the flowering branches are usually plagiotropic.
The leaves are arranged alternate, simple, highly variable but two main forms exist (heterophylly), lobed (often on plagiotropic branches) or unlobed (often on orthotropic branches).
The unlobed form is with petiole up to 1.5 cm long, with lance-shaped blade, measures 16-23 cm x 9-12 cm, heart-shaped at base, denticulate and palmate-pinnately veined while the lobed form is with petiole 10-40 cm long, 3-5-lobed blade, cordate-ovate in outline, measures up to 30-40 cm x 30-40 cm, with palmately 3-5-7-veined base and irregularly dentate margin.
The inflorescence is a leaf-opposed or terminal and 1-4-flowered cyme (usually only 1 flower develops). The flowers are pendent, 3-5 cm in diametre, bisexual and 5-merous. The peduncle and pedicel are each 1-3 cm long and slightly enlarged in fruit. The sepal is deeply divided, with 5 entire lobes, triangular, measuring about 15-20 mm x 6 mm and greenish. There are 5 petals which are spoon-shaped, measuring 2-3.5 cm x 1 cm, concave and white at base, with dark purple, red or yellow blade and fringed. The staminal tube is short, with 5 fascicles of anthers that alternate with 5 petal-like staminodes apically. Each fascicle is with 3(-4) anthers. The pistil is with a 5-lobed and 5-celled ovary which is 2-3 mm long, that contains numerous ovules, and 5 stigmatic style branches which are 1-2.5 mm long.
The fruit is an obconical capsule, measures about 4-5 cm x 3-4 cm, rounded at base, with truncate top, 5-winged and angled, beaked sometimes, enveloped by a slightly enlarged sepal, densely prickly hairy, with apical portion loculicidal, septicidally dehiscent lateral parts and with numerous seeds. The seed is cylindrical to obovoid, measures 3-4 mm x 2 mm, without wings or aril and black.
The distribution area of Abroma augusta is characterised by mean daily temperatures of 27-30°C in the hottest months, an average annual rainfall of at least 1500 mm, and a high relative humidity. It is not suitable for areas with a marked dry season. A. augusta is not frost-hardy and so not found at altitudes above 1100 m. It is a short-day plant. The best soils for A. augusta are fertile alluvials with a good structure and drainage, as it does not tolerate waterlogging for a long period. However, it will also survive and grow when soil conditions are less favourable. When occurring naturally, A. augusta is found in thickets or tufts, secondary forests, waste places and village borders and along railways and roads, seemingly preferring forest edges and the banks of clearings or watercourses. As a light-loving plant, it does not occur in primary forest. In the Moluccas, it occurs in dry valleys on poor, sandy locations or in fallow fields.