Morphological description. Prostrate perennial, multi-branching, strongly stoloniferous stems, rooting freely from stolons and lower nodes of aerial stems. Stems angular, reddish-brown, tomentose, the brown hairs 1.5–2.0 mm long. Stolons become woody with age and practically glabrous. Height rarely exceeds 15–20 cm. Leaves trifoliate, stalk of the terminal leaflet (4–5 mm long) four to five times longer than those of lateral leaflets. Terminal leaflet (15–20 mm long and 10–15 mm wide) larger than lateral leaflets (12–15 mm long and 8–10 mm wide). Leaves stipulate, the stipules long (4–6 mm), tapering, with hairy margins and parallel venation. Leaflets subtended by four inconspicuous stipules, obovate, margins entire, apex slightly emarginate, reticulate venation, densely pubescent (hairs whitish coloured) on both dorsal and ventral surface. Petioles angular, 10–15 mm long, reddish-brown, and covered with brown hairs. Flowers small (3–5 mm long), pink, giving rise to a 3–6 jointed, undulate (on dorsal edge) pod, which fractures at the joints on maturity. Pods 12–25 mm long, 4–5 mm wide, finely pubescent. Segments break and stick to hair or clothing when ripe (hence name of tick trefoil). Seeds kidney shaped 2.25–2.50 mm long and 1.50–1.75 mm wide, yellowish brown turning dark brown with age; seed coat glabrous .
Desmodium heterophyllum. Photo copyright © 2013 by Chris Gardiner.
Scientific name. Desmodium heterophyllum (Willd.) DC.
Synonyms. Desmodium triflorum (L.) DC. var. majus Wight & Arn. Hedysarum heterophyllum Willd. Meibomia heterophylla (Willd.) Kuntze
Family/tribe Family: Fabaceae (alt. Leguminosae) subfamily: Faboideae tribe: Desmodieae subtribe: Desmodiinae. Also placed in Papilionaceae.
Common names. hetero, Spanish clover (English); variable-leaf tick trefoil (USA); senivakacegu, wakutu (Fiji); sisik betook, heuheulangan, sukut jareman (Indonesia); rumput sisek naga, rumput telinga tikus (Malaysia) ya maengmi (Thailand); han the, trang qu’a di diep (Vietnam); trom prei, smau am bok (Cambodia).
Distribution. Native to: Asia : Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Philippines, Sri Lanka, Taiwan, Thailand, Vietnam. Pacific Region: Papua New Guinea.
Naturalised in: Pacific Islands, humid north-east Australia.
Uses/applications Valuable component of grazed native pastures and of sown pastures dominated by creeping grasses. Tolerance to spread under heavy grazing allows it to persist under conditions of management that result in the loss of most other legumes. It has been used as ground cover under pepper gardens in Sarawak.
Soil requirements. Grows on a wide range of soils from sands to clays. Very efficient at extracting phosphorus from infertile soils and will tolerate low pH and high Al. Hetero has little salt tolerance.
Moisture. Requires at least 1,500 mm rainfall, up to 4,000 mm AAR. Hetero is not drought -tolerant but will persist through moderate dry seasons of 5 months length. It will tolerate waterlogged soils and short-term flooding. Accessions have performed well in the seasonally flooded savannas of Colombia.
Temperature. Warm-season tropical legume with no frost tolerance .
Light. Very shade tolerant and is often found under the canopy of shrubs in grassland. It persists in well-grazed pastures under mature coconut plantations and yield is less affected under 50% light than many other tropical legumes.
Reproductive development. The species flowers and produces seed over a long period; as each segment of the pod dehisces at maturity, seed production is difficult.
Defoliation. Extremely tolerant of heavy grazing due to multi-branching stems that root at the nodes, and will spread under these conditions. Difficult to harvest in cut-and-carry systems due to its prostrate growth habit .
Fire. Hetero will recover after fire from plant or seed, but hetero-rich pastures with creeping grasses are rarely burnt.
Desmodium heterophyllum. Photo copyright ©2013 by CIAT
Guidelines for the establishment and management of sown pastures.
Establishment. Can be sown from seed, but this is rarely available commercially due to difficulty of harvest. Seed should be inoculated with an appropriate rhizobium (QA 982 or CB 2085 in Australia). Almost invariably planted from cuttings of rooted stolons and aerial stems into moist soil where it will spread rapidly due to its free branching habit and free seeding. If sown from seed, seeding rates can be as low as 0.25–0.5 kg/ha. Grazing animals spread seed through dung and from yet-to-dehisce seedpod segments adhering to hair.
Fertiliser. Hetero will grow well in infertile soils but will respond vigorously to added P (and S).
Compatibility. (with other species) Hetero is incompatible with tall tussock grasses but combines well with creeping or low-growing grasses.
Grasses: Brachiaria decumbens , B. humidicola , Dichanthium caricosum , Digitaria eriantha , Axonopus spp.
Legumes: Desmodium triflorum , Alysicarpus vaginalis .
Pests and diseases. Susceptible to root knot nematodes (Meloidogyne spp.) on lighter soils; also affected by little leaf mycoplasma organisms and some leaf fungi, but these are rarely important under grazing. Foliar blight (Rhizoctonia solani) is often observed on the species in the humid regions of Central and South America. High tolerance of insect pests.
Ability to spread. Will spread and naturalise under suitable conditions as evidenced by its spread and persistence in the Pacific region.
Weed potential. Only well adapted to heavily grazed situations, usually in association with low-growing grasses, especially with fertiliser applications, so weed potential is limited.
Dry matter. Yields of about 2 t/ha/yr have been obtained from grass-legume pastures and about 3–5 t/ha/yr under plantation crops when grown in pure stands.
Animal production. In Fiji, LWGs of over 500 kg/ha/yr recorded on fertilised hetero in native pastures. Naturalised hetero invaded pastures previously fertilised and sown with Siratro (Macroptilium atropurpureum ), which declined at stocking rate of 3.5 head/ha. In northern Australia, LWGs of over 700 kg/ha/yr have been obtained off signal grass (Brachiaria decumbens )/hetero and pangola (Digitaria eriantha )/hetero pastures. In Samoa, LWGs of steers grazing a pasture of Ischamemum indicum were 220 kg/ha/yr; steers on I. indicum/hetero gained 370 kg/ha/yr. Nitrogen fixation by hetero was 64 kg N and 110 kg/ha/year N with tall guinea (Panicum maximum ) grass and B. miliiformis respectively.
Genetics/breeding. 2n = 22 and self-compatible, although it may be predominantly out-crossing.
Seed production. Hetero is free-seeding but harvesting is difficult because the flowering period is much extended, it has a prostrate growth habit and seeds dehisce from the individual pod segments soon after maturity. Consequently seed must be hand-harvested from plants over a long period of time or vacuum-harvested from the soil surface. Seed yields of 35 kg/ha have been achieved.
Herbicide effects. No information available.
- Well adapted to heavy grazing.
- Compatible with creeping grasses.
- Natural spread under grazing.
- Can be planted vegetatively.
- Good shade tolerance.
- Adapted to high rainfall regions only.
- No commercial seed available.
- Hacker, J.B. and Teitzel, J.K. (1992) Desmodium heterophyllum (Willd.) DC. In: ‘t Mannetje, L. and Jones, R.M. (eds) Plant Resources of South-East Asia No. 4. Forages. pp. 110–112. (Pudoc Scientific Publishers, Wageningen, the Netherlands).
- Imrie, B.C., Jones R.M. and Kerridge, P.C. (1983) Desmodium. In: Burt, R.L., Rotar, P.P., Walker, J.L. and Silvey, M.W. (eds) The role of Centrosema, Desmodium and Stylosanthes in improving tropical pastures. pp 97–140. (Westview Press, Boulder, Colorado United States).
- Kaligas, D.A. and Sumolang, C. (1991) Forages species for coconut plantations in North Sulawesi. In: Shelton, H.M. and Stur, W.W. (eds) Forages for Plantation Crops. Proceedings of a workshop, Sanur Beach, Bali, Indonesia. 27-29 June 1990. ACIAR Proceedings No. 32 .
- Partridge, I.J. (1980) The effect of grazing and superphosphate on a naturalised legume , Desmodium heterophyllum , on hill land in Fiji. Tropical Grasslands, 14, 63–68.
- Partridge, I.J. (1986) Effect of stocking rate and superphosphate level on an oversown fire climax grassland of mission grass (Pennisetum polystachyon) in Fiji 1. Botanical composition of pasture . 2. Animal production. Tropical Grasslands, 20, 166–179.
- Rika, I.K., Mendra, I.K, Oka Nurjaya, M.G. and Gusti Oka, M. (1991) New forage species for coconut plantations in Bali. In: Shelton, H.M. and Stur, W.W. (eds) Forages for Plantation Crops. Proceedings of a workshop, Sanur Beach, Bali, Indonesia. 27-29 June 1990. ACIAR Proceedings No. 32 .
- Stür, W.W. (1991) Screening forage species for shade tolerance – a preliminary report. In: Shelton, H.M. and Stur, W.W. (eds) Forages for Plantation Crops. Proceedings of a workshop, Sanur Beach, Bali, Indonesia. 27-29 June 1990. ACIAR Proceedings No. 32 .