3004

11: Auxiliary plants

Derris microphylla (Miquel) B.D. Jackson

Index kewensis 1: 332 (1893).

LEGUMINOSAE - PAPILIONOIDEAE

2n = unknown

Brachypterum microphyllum Miquel (1861), Derris dalbergioides Baker (1878), Deguelia microphylla (Miquel) Valeton (1904).

Vetch tree (En). Indonesia: kayu retak (Palembang). Malaysia: daun berayai, batai, betek (Peninsular). Thailand: khangten (south-eastern), di-ngu, fantae (peninsular).

Derris microphylla occurs naturally in Sumatra, Peninsular Malaysia, Thailand, Burma (Myanmar) and possibly in Indo-China. Its natural occurrence in Java, where it is often planted, is uncertain.

In Java, Derris microphylla is occasionally grown as a shade tree in cocoa, coffee and tea plantations especially on poor soils. It is also used as green manure. The wood is used as building material and as firewood. In Malaysia a poultice of roots or bark is used to treat itch. Its abundant purple flowers make it a distinctive ornamental tree.

Many Derris species contain rotenone and related compounds, which have insecticidal and piscicidal properties. It is unlikely that Derris microphylla contains exploitable quantities of these compounds. All parts produce a foetid smell when crushed.

Tree with several ascending branches and umbrella-shaped, feathery crown, 5—20 m tall; bark light-grey to brown, slightly fissured. Branchlets, petioles and buds golden-brown silky, glabrescent. Leaves imparipinnate, petiole and rachis 9—20 cm long; petiolule 1—2 mm long; leaflets 19—43, elliptical-oblong, 1.5—3.2 cm x 0.8—1.2 cm, rounded-emarginate at both ends, both surfaces thinly appressed brown hairy, glaucous below. Inflorescence an axillary raceme, 2—13 cm long, 1—3 together; flowers 7—8 mm long; pedicel 0.5—1.5 cm long; calyx campanulate; corolla dark-red to violet; standard 9 mm x 7 mm, bearing 2 glands at base; stamens 10, monadelphous, 1 stamen free at top and bottom but adnate to stamen tube in centre. Pod flat, in outline elliptical to linear-lanceolate, 2.5—7 cm x 1.2—1.7 cm, 1—2(—5)-seeded, indehiscent, narrowed at both ends, glabrous to puberulous, leaf-like along dorsal suture with a 1—2 mm wide wing. Seed 6 mm x 3 mm, brown-green.
Derris microphylla does not grow very fast and does not produce large amounts of green matter. The root system, which is superficial, produces large numbers of root nodules and, when damaged, large numbers of saplings. In Java, Derris microphylla flowers in August—January.
Derris microphylla is classified in section Brachypterum (Wight & Arnott) Benth. of the genus Derris Lour.; this section is sometimes considered a separate genus and in that case the correct name of the species is Brachypterum microphyllum Miquel.

In Java and Peninsular Malaysia, Derris microphylla occurs from 200—1200 m altitude. It is tolerant of strong winds. To provide shade in plantations it is mostly planted on soils too poor for Leucaena leucocephala (Lamk) de Wit or Paraserianthes falcataria (L.) Nielsen.

Propagation by seed and by cuttings is easy. For firewood and timber use the recommended planting distance is about 3 m x 3 m, gradually thinned out to a final spacing after 10 years of 10 m x 10 m. Experiences with Derris microphylla grown as a shade tree in tree crops are mixed. Early reports, especially from tea plantations, indicate positive results, later reports from coffee and cocoa plantations draw attention to its slower growth, more superficial root system and lower production of organic matter resulting in poorer growth of the main crop than is the case with shade trees like Paraserianthes falcataria and Erythrina subumbrans (Hassk.) Merrill. However, it requires little maintenance, and pruning and pollarding are well tolerated. Derris microphylla is attacked by the fungi Ganoderma pseudoferreum, Rosellinia and Ustulina zonata which affect its root system, and by several bagworm species. It is resistant to most borers. In the mid 1940s large numbers of trees died in West Java of unknown causes.
Derris microphylla is a suitable tree for filling in gaps for soil protection in mature tree plantations, where it is easier to establish than most other trees.

A small collection of Derris germplasm including material of Derris microphylla is being maintained at the National Germplasm Repository, Miami, United States.

Derris microphylla may continue to play a role as a shade tree in tree crops on poor soils. On more fertile soils Paraserianthes falcataria and Leucaena leucocephala generally give better results. It remains a useful tree for filling in gaps in plantations, where it is difficult to establish other trees.

Backer C.A. & van Slooten, D.F., 1924. Geïllustreerd handboek van de Javaansche theeonkruiden en hunne beteekenis voor de cultuur [Illustrated handbook of weeds of Javanese tea plantations and their significance for tea-growing]. Ruygrok, Batavia, Dutch East Indies. p. 147, 147a.
Polhill, R.M., 1971. Some observations on the generic limits in Dalbergieae-Lonchocarpinae. Kew Bulletin 25: 259-273.
Schoorel, A.F., 1949. Handleiding voor de theecultuur [Manual of tea cultivation]. De Centrale Vereniging tot Beheer van Proefstations voor de overjarige Cultures in Indonesië. Veenman, Wageningen, the Netherlands. pp. 133-134.
Valeton, T., 1906. Deguelia microphylla Miq. In: Koorders, S.H. & Valeton, T. (Editors): Icones bogorienses. Vol. 2, t. 129, pp. 141-142.
Whitmore, T.C. & Ng, F.S.P., 1983. Tree Flora of Malaya: a manual for foresters. 2nd edition, Vol. 1. Malayan Forest Records No 26. Forest Research Institute of Malaysia, Longman Malaysia, Sendirian Berhad, Kuala Lumpur, Malaysia. pp. 290-291.

K. Thothathri & Rugayah

Thothathri, K. & Rugayah, 1997. Derris microphylla (Miquel) B.D. Jackson. In: Faridah Hanum, I & van der Maesen, L.J.G. (Editors): Plant Resources of South-East Asia No 11: Auxiliary plants. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea