Hypaphorus subumbrans Hassk.

A deciduous, medium-sized tree, 5-25 m tall, trunk reaching 60 cm in diameter; crown spreading; bark whitish; trunk and branches armed with stout prickles, in cultivation mostly unarmed. Leaves alternate, trifoliolate; stipules orbicular, small, caducous; rachis 10-21 cm long, inclusive of the petiole of 8-16 cm which is thickened at the base; petiolule up to 7 mm long; stipels 2, below the lateral leaflets, stipitate, cup-like, glandular, 2 mm long; leaflets ovate-triangular-rhomboid, terminal one largest and 8-16 cm x 6-14 cm, base rounded or cordate, apex acuminate, glabrous. Inflorescence racemose, in the upper leaf axils, 5-23 cm long, brownish tomentose; flowers many, arranged in group of 3; peduncle terete, robust, 3-15 cm long, pubescent; pedicle 2-3 mm long, in fruit up to 6 mm; calyx campanulate, 1-1.5 cm long, splitting open up to halfway down, tomentose, yellow-green; petals 5, red; standard broadly elliptical, shortly clawed, 2.5-4 cm x 2-3 cm, scarlet, at base inside with numerous white stripes; wings as long as the keel or slightly longer, about 1.5 cm long, pale red with a blackish upper margin; stamens 10, 3-3.5 cm long, monadelphous but vexillary stamen slightly shorter than other ones and only connate for the lower 0.5-1 cm, pinkish red; pistil with hairy ovary. Pod flat, curved, 10-15 cm long, on a slender stalk 3-4.5 cm long, lower part seedless and 2-2.5 cm wide, upper part thicker, 1-1.5 cm wide and 1-5 seeded, septate between the seeds, dehiscent. Seed ellipsoid, 7-18 mm x 5-11 mm, smooth, dull black. An unarmed hybrid between E. subumbrans and E. variegata L., named 'dadap solo', probably originated near Surakarta in Java, and is widely planted. It is shorter than other unarmed forms of E. subumbrans, has a denser crown and rarely produces viable seed. The necklace-shaped pods of E. subumbrans are highly characteristic and can be used to identify the species.

In Singapore E. subumbrans flowers from October to December during the height of the wet season. In Java, flowering and fruiting occur almost throughout the year, with peaks in February-March and October-November. Thornless forms generally produce fewer flowers and fruit than the armed, wild ones. As in other Erythrina spp., the red, odourless, nectar-rich flowers are so constructed that cross-pollination is universal. Pollination is by birds which feed on the abundant nectar. Seed are dispersed by water and occasionally by birds.

E. subumbrans occurs at low and medium altitudes, in moist valleys, near streams, in open locations and secondary forest. The trees are fairly tolerant of wind, unless branches have been damaged by borers.

E. subumbrans grows easly from large cuttings, even if they are 25 cm in diameter. It can be propagated by seed, but seedlings of thornless trees are generally armed.

Plantation: The spacings employed depend on the spacing of the main crop, pruning regime, and growth rate of the trees. In Western Samoa, a spacing of 1.5 m x 1.5 m is used in cocoa, 2 m x 2 m when planted as a shade for taro. Husbandry: Some of the leaves are shed during the dry season. However, in Java, trees are never completely leafless. Prunning before the start of the dry seasons can prevent leaves being shed during the dry season. Cultivated thornless forms may reach an age of 40-50 years but often die earlier because of diseases and pests. Pruning and polarding are very well tolerated. In tea plantations in Sri Lanka it is customary to pollard twice a year. In coffee and tea plantation in Java, pruning is generally done once a year. The frequency of lopping depends on the requirements of the main crop, the labour supply and the growth rate of the trees and can be up to 4 times a year. However, mortality may occur if pruning is followed by a prolonged dry spell. Where E. subumbrans is pruned, it is sometimes used as a medium level shade tree, interplanted with taller shade trees like Paraserianthes falcataria (L.) Nielsen or Grevillea robusta Cunn. ex R. Br. Elsewhere, E. subumbrans is not pruned and is used for high shade, interplanted with Leucaena leucocephala (Lamk) de Wit providing low shade. In Western Samoa, yam vines planted in a circle around an E. subumbrans tree are allowed to cover the canopy and suppress its growth.

Diseases: At the end of the 19th Century in Java, E. subumbrans was heavily attacked by a root disease, which locally destroyed all trees and prevented its further planting. Little has been published about this disease, its cause and importance today. The fungus Septobasidium bogoriense often grows on the bark. It does not cause direct damage, but keeps the bark moist, creating favourable conditions for pathogenic fungi like Corticium salmonicolor, Fomes spp., and Ustulina zonata. Pests: Several boring insects attack the wood and bark of branches, often causing them to break and making them susceptible to rot. The leaves of E. subumbrans are damaged by many insects and defoliation is common. Normally, the trees recover rapidly.

Boundary or barrier or support: E. subumbrans is still planted on a smaller scale in Indonesia as live support for betel (Piper betle L.), pepper (Piper nigrum L.) and Vanilla (Vanilla planivolia H.C. Andrews) vines. In Malaysia, as a live support for yams (Dioscorea spp.) and in Burma (Myanmar) and India, it is often grown to support betel and pepper vines. Shade or shelter: E. subumbrans was one of the most widely planted shade trees for coffee and other crops in Indonesia. It is still planted on a smaller scale in Indonesia for shade in cocoa, coffee and tea plantations. In Malaysia, it is used as a shade tree for coffee and tea; in Western Samoa, for cocoa and taro (Colocasia esculenta (L.) Schott) and in Sri Lanka for tea and cocoa.

Fodder: The leaves are a good and palatable fodder but if eaten by rabbits it can cause sterility and death. In Western Samoa, an addition of 5% leucaena meal and 5% dried and ground dadap to the starter diets of chicken improved their gains in weight. Food: Very young leaves are steamed and eaten in salads in Java. Medicine: Bark and leaves are used medicinally, sometimes mixed with parts of other plants. A decoction of the bark is taken to the treat spleen afflictions in the philippines. In Indonesia pounded young leaves are used as a poultice for women soon after giving birth and against headache; juice of leave is used as an eye-wash and a decoction of the leaves is given for coughs. Timber: The wood is utilized in canoe and raft building.