Gigantochloa wrayi

Gigantochloa wrayi Gamble

Ann. Roy. Bot. Gard. Calcutta 7: 64 (1896).
2n = unknown

Origin and geographic distribution
G. wrayi is native to Peninsular Malaysia and southern Thailand. It has also been found cultivated in southern Sumatra (Indonesia). In its native area it is probably also cultivated in villages. For map click: Map436.TIF.

In Peninsular Malaysia, especially in the north, G. wrayi occurs sympatrically with G. scortechinii Gamble and its culms are of comparable quality and used in the same way, e.g. to prepare incensed prayer sticks used by the Chinese community, vegetable baskets, poultry cages and handicrafts. In rural areas in Peninsular Malaysia and southern Sumatra they are used when needed for fences, poles, roughly plaited house walls and other household items.

Production and international trade
G. wrayi is only used locally and no statistics on production or trade are available.

Densely tufted, sympodial bamboo. Culm erect, slightly arching outwards, up to 12 m tall, diameter 2-20 cm, plain green or sometimes streaked yellow at the base; internodes non-waxy, up to 40 cm long, with scattered appressed dark-brown hairs on the upper parts; nodes not conspicuously swollen. Branches at each midculm node arising from a single bud, consisting of a dominant primary branch, 1-2 subdominant branches from its base and several lesser branchlets of higher orders. Culm sheath pale green, sometimes with faint yellow stripes, covered with dark brown hairs; blade broadly triangular on lower sheaths, broadly lanceolate on midculm and upper sheaths, green or sometimes flushed purple, spreading to reflexed, hirsute at base and along midrib on lower half; ligule lacerate, the base 1-2 mm tall, the lacerations to 8 mm long, bristly along rim when young; auricles low and rimlike, 2-4 mm long, sometimes raised at the outer ends, glabrous except for a few scattered pale bristles 2-5 mm long near the outer ends, dark green to dark purple. Leaf blade 9-40 cm x 1.5-6 cm, lower surface covered with soft pale hairs; ligule subentire, not bristly, 1-2 mm long; auricles small rounded lobes 1-2 mm long with a few pale bristles 2-3 mm long. Pseudospikelet 10-20 mm long, with 2-3 gemmiferous bracts, 3-4 glumes, 3-4 perfect florets and a vestigial terminal floret represented by an empty lemma 8-17 mm long. Caryopsis cylindrical-ellipsoidal, about 10 mm long, grooved on one side, apex thickened and hairy.

Growth and development
No information exists from systematically observed populations. It appears that the growth is very similar to that of G. scortechinii, as observed sympatric clumps apparently have the same vigour. Flowering occurs on one to several culms in a clump, which can continue to show new vegetative growth during and after such flowering.

Other botanical information
In the field G. wrayi can be distinguished from G. scortechinii by its non-waxy culms with scattered dark hairs at the upper parts of internodes.

G. wrayi is common in Peninsular Malaysia only in the north, on alluvial sites and in the foothills of the Main Range. It establishes naturally on poor clayey soils but does not produce as large culms as when it grows on alluvial soils. Nevertheless in many wasteland areas it can establish as whole stands, mixed with secondary-forest trees and also with G. scortechinii and sometimes Schizostachyum grande Ridley. In such dense stands, its leaf litter accumulates on the ground and appears to prevent effective establishment of other plants.

Rhizome cuttings (offsets) and culm cuttings can be effectively used in vegetative propagation. Any experience with systematic planting has not been reported.

Genetic resources and breeding
Wild populations of G. wrayi are composed of both seed individuals and clones which establish from clump or rhizome fragmentation. There are no germplasm collections and breeding programmes for G. wrayi.

G. wrayi is a useful bamboo, and may be usefully brought under organized cultivation for culm production. More research is needed on cultivation methods, properties and applications. Germplasm collection is urgently needed.

K.M. Wong

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