Gigantochloa ligulata

Gigantochloa ligulata Gamble

Ann. Roy. Bot. Gard. Calcutta 7: 67 (1896).
2n = unknown

Origin and geographic distribution
G. ligulata is native to the northern part of Peninsular Malaysia (Perlis, Kedah, Kelantan) and the southern, peninsular part of Thailand (Surathani). For map click: Map425.TIF.

In Peninsular Malaysia (Kedah), the slender, thick-walled culms are used to frame chairs, tables and screens, as walking sticks and as poles for vegetable support. In Thailand they are used for rural construction, agricultural implements and as raw material for paperpulp. Young shoots are locally used as a vegetable and considered as delicious in northern Peninsular Malaysia. Sometimes G. ligulata is grown as an ornamental.

Production and international trade
In its native area G. ligulata is of considerable economic importance, but no statistics are available. Consumption and trade are mainly local and the useful parts are collected from natural stands.

Although culms of G. ligulata are thick-walled or often even solid, they can be bent easily.

Densely tufted, sympodial bamboo. Culm 6-9(-15) m tall, diameter 1.5-4(-8) cm, wall usually about 10 mm thick, often solid in major part (not at base or at top); internodes 20-35(-45) cm long, dark green often with pale green streaks, covered with pale hairs and when young with very dark brown hairs below the nodes, glabrescent later; nodes prominent. Branches arising from the nodes in the lower half of the culm, few from the midculm nodes and usually absent from the upper nodes; the middle branch is dominant and often as big as the main culm. Culm sheath 14-22(-30) cm long, slightly persistent, green to yellow-green, covered with dark brown to black hairs that are easily shed; blade erect, narrowly to broadly lanceolate, 2-5 cm wide, about 5 cm long on the lower to middle part of the culm, 18-20 cm long on the higher part, glabrous, not deciduous; ligule thin, very prominent, 5-10(-20) mm long, irregularly incised, longest at its ends; auricles more or less down-curved on the edges of the top of the sheath on each side of the base of the blade, forming a low firm smooth rim 1 mm tall and 1.5-2.5 mm long in lateral extent, without or almost without bristles. Young shoots green, ending in a sharp pointed apex. Leaf blade oblong-lanceolate, 27-30(-42) cm x 4-6(-7) cm, soft pale hairy below; sheath glabrous or with scattered pale hairs; ligule very pronounced, thin, 2-5 cm long, usually entire; auricles inconspicuous. Inflorescences terminating leafy and leafless branches, drooping, 80 cm or longer, comprising pseudospikelets in clusters of up to 60 at each node and 1-5 cm apart; spikelet ovate-lanceolate in outline, 12-15 mm x 4 mm, consisting of 3-4 glumes, 2-4 perfect florets and 1 sterile floret; lemma fringed with dark brown hairs. Caryopsis ovoid, 9 mm x 2 mm, hairy at the apex.

Growth and development
About 8 weeks after sowing, the first culm of a seedling is 13 cm tall with 5-6 expanded leaves. A mature clump of G. ligulata contains (15-)30-40(-70) culms and usually produces 13-15 young shoots per year. Sporadic flowering is quite often seen but gregarious flowering of whole clumps has rarely been reported. Gregarious flowering of many clumps over large areas has never been observed. The flowering cycle is still not known. In a case of gregarious flowering in Kedah the flowering period lasted 6 months (November-April), after which the clump died.

Other botanical information
G. ligulata is a very variable species that still needs further investigation. Roughly, two groups of specimens can be distinguished (unnamed): one with medium-sized, thick-walled culms with 2 perfect florets in the pseudospikelets and another with larger culms, larger culm-sheath ligules and 3-4 perfect florets in the pseudospikelets (the vernacular names for the latter group in Peninsular Malaysia are: buloh bilalai, buloh gala, buloh mata rusa). G. ligulata much resembles G. latifolia Ridley and they possibly form a hybrid complex.

In Peninsular Malaysia, G. ligulata is found in overlogged forest, margins of secondary forest and wastelands along roadsides, up to 1500 m altitude. In southern Thailand it is found in mixed forest on sandy soil near the coast and on wastelands along the roads.

G. ligulata culms and young shoots are harvested from wild populations only. First trials on cultivation are being carried out in Malaysia. Deglumed seed germinates within 2 weeks after sowing in a 1:3 soil-sand mixture (germination rate 76%). Application of fertilizer (1 g NPK (15:15:15) per plant) every 2 weeks considerably promotes the growth and development of seedlings.

Genetic resources and breeding
No germplasm collections or breeding programmes for G. ligulata are known to exist. Germplasm collection is urgently recommended.

Like many other wild species in the South-East Asian region (e.g. G. scortechinii Gamble (Peninsular Malaysia) and G. albociliata (Munro) Kurz (Thailand, Indo-China)), G. ligulata has the potential to become a sustainable source of raw material for cottage industries. The prospects are promising, but more investigation on relevant aspects is required.

S. Dransfield

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