Ischaemum muticum (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Ischaemum muticum L.

Protologue: Sp. Pl.: 1049 (1753).

Family: Gramineae

Chromosome number: 2n= unknown

Synonyms

Ischaemum repens Roxb. (1820), I. glabratum Presl (1830), Andropogon repens (Roxb.) Steud. (1854).

Vernacular names

• Seashore centipede grass, drought grass (En)
• Indonesia: suket resap (Javanese), rumput kerupet (Bangka)
• Malaysia: rumput kemarau, rumput tembaga jantan
• Thailand: ya-waitham (eastern)
• Vietnam: mô[m] trui.

Origin and geographic distribution

I. muticum is indigenous to South and South-East Asia. It is widely distributed in Malaysia, particularly near the sea and in sandy places, and in Thailand, Indonesia, the Philippines, Sri Lanka, India, Burma, and some islands in the western Pacific Ocean. It has been introduced to West Africa and Australia.

Uses

I. muticum provides fodder, but is also used to protect soil from erosion (especially coastal sand dunes) and to make compost and mulch. It is a weed in many annual and perennial crops.

Properties

I. muticum is a palatable and nutritious grass and N concentrations of 1.5-2.4% have been measured.

Botany

A leafy, much branched, stoloniferous spreading perennial, rooting at the nodes where they touch the soil, sometimes scrambling several m high among and over shrubs; stolons long, up to 5 m or more, with numerous joints and up to 6 mm in diameter, covered by slightly overlapping pale or purple leaf-sheaths with extremely short leaf-blades, resembling culm-sheaths in bamboos; flowering culms up to 60 cm tall, glabrous, often red. Leaf-sheath ciliate along outer margin; ligule truncate, small, shortly ciliate; leaf-blade ovate-lanceolate to linear, 2-18 cm × 0.5-2 cm, apex acute, base cordate, narrowing into a short pseudo-petiole. Inflorescence terminal, composed of 2 racemes closely pressed together, each 1.5-5.5 cm long, rarely fully exserted; spikelets arranged in pairs, one sessile and one pedicelled, on one side of a triangular rachis, straw-coloured; the sessile spikelet glabrous, lower glume distinctly reticulately nerved near the apex, enfolding the spikelet base, upper glume with a strongly keeled acute apex; lower floret male or hermaphrodite, upper floret hermaphrodite; the pedicelled spikelet hairy, lower glume chartaceous, with a winged keel, upper glume subchartaceous; the upper lemma of both spikelets short-awned, awn included in spikelet.

Ecology

I. muticum is an opportunistic and agressive colonizer of open or disturbed habitats and can develop into huge thickets in drainage canals and ditches. On the edges of secondary forest, plants grow very large, scrambling among bushes. It tolerates wet conditions, especially flooding, and short dry periods. It is usually found in areas receiving more than 1500 mm rainfall annually. Its presence is sometimes regarded as indicative of poor soil fertility.

Agronomy

I. muticum can be propagated by stem cuttings and by seed. Newly harvested seed is dormant, so scarification is desirable to improve germination. Planting with stem cuttings gives faster establishment than sowing seed.

Although adapted to infertile conditions, it responds to fertilizer application on such soils.

There are no serious diseases and pests of I. muticum although it is occasionally infested with smut.

High DM yields of up to 25 t/ha per year have been measured. It is usually harvested by grazing animals and only occasionally by cutting. Both fresh and dry foliage can be used for composting or mulch.

Genetic resources and breeding

It is unlikely that substantial germplasm collections are being maintained and there are no breeding programmes.

Prospects

I. muticum is a useful forage in specific situations, but it is uncertain whether it will be specifically cultivated in the future.

Literature

• Backer, C.A. & Bakhuizen van den Brink, R.C., 1968. Flora of Java. Vol. 3. Wolters-Noordhoff, Groningen, the Netherlands. p. 592.
• Barnes, D.E. & Chan, L.G., 1990. Common weeds of Malaysia and their control. Ancom Berhad, Shah Alam, Malaysia. p. 22.
• Gilliland, H.B., Holttum, R.E. & Bor, N.L., 1971. Grasses of Malaya. In: Burkill, H.M. (Editor): Flora of Malaya. Vol. 3. Government Printing Office, Singapore. pp. 255-257.

Authors

I.B. Ipor & B.B. Baki