Phyllostachys aurea

Phyllostachys aurea Carr. ex A. and C. Rivière

Bull. Soc. Acclim. ser. 3, 5: 716, f. 36 (1878).
2n = 48 (tetraploid)

Origin and geographic distribution
P. aurea is believed to originate from temperate and subtropical southern China and Japan. For map click: Map85.TIF. It has been introduced into most countries of the world and is often grown as an ornamental, even in temperate climates. In some countries it has also naturalized, e.g. in Indonesia (Merapi Mountain in Central Java).

Because of the abnormal internodes (irregularly shortened and swollen) in the lower part of the culms, P. aurea is a popular garden ornamental (also as hedge). Its basal culm parts are used and sold as walking sticks, umbrella and fan handles and as various other souvenirs. The straight upper culm parts are used as fishing rods, ski poles, javelins and for furniture and construction. The young shoots are occasionally used as a vegetable.

Production and international trade T
here are no plantations of P. aurea. Production and trade are mainly local for the tourist souvenir industry but statistics are not available.

Open, sometimes tufted, monopodial bamboo. Culm erect, straight, 2-8(-12) m tall, 2-3(-9) cm in diameter, wall 4-8 mm thick, green when young, golden-yellow when older; internodes 10-20 cm long, below the nodes white powdery waxy, the lower ones often irregularly shortened and swollen, thrusting the sheath scars into an irregularly slanted zigzag pattern; nodes prominent, lower ones close together and oblique, upper ones distant and horizontal, young sheath scars fringed with short white hairs. Branches usually paired in the midculm part, unequal in thickness. Culm sheath 12-18 cm long, promptly deciduous, when young green or light orange-yellow with purple-red or light green ribbed striations and brown spots, covered with short white hairs toward the base; blade lanceolate to narrowly lanceolate, 3-6 cm long, erect or spreading, sometimes wrinkled; ligule 1-2 mm long, long ciliate at apex; auricles absent. Young shoots light brownish-yellow, sometimes reddish, brownish spotted or dotted. Leaf blade lanceolate, 5-15 cm x 5-20 mm, glabrous to densely soft-hairy, margins spinulose-scabrous; sheath 2.5-3.5 cm long, minutely soft hairy when young, glabrous with age, sparsely ciliolate along the margins; ligule 1 mm long, long ciliate; auricles rudimentary or lacking, when present bearing 0-3 bristles. Inflorescences borne on leafy or leafless branches, occupying nearly the whole culm; spikelet 18-25 mm long, usually with 1 papery glume and 2 fertile florets. Caryopsis linear-lanceolate in outline, 6-8 mm x 1.5-2.0 mm, grooved on back, style persistent.

Growth and development
Young shoots appear in spring (April in China); they grow rapidly, reaching full height within 1 month, after which the branches and leaves develop before the summer starts. A culm matures in 3-5 years. Flowering is rare, but sporadic and gregarious flowering has been observed. Gregarious flowering may occur when a clump is 15-30 years old, after which the clump does not die. In Java P. aurea has never flowered. In Japan one gregarious flowering period has been reported to occur from 1916-1921.

Other botanical information
P. aurea is a variable species and numerous subclassifications have been proposed. Some better known cultivars are:
- 'Albo-variegata': culms slender, leaves striped white.
- 'Holochrysa': culms yellow, sometimes striped green; leaves occasionally striped.
- 'Violascens': culms up to 6 m tall, swollen, green and finally striped purple or yellow in time, ultimately violet; nodes prominent; branches short and dense; leaves up to 12 cm long, glossy above, glaucous beneath.

Small natural forests of P. aurea occur in southeastern China from low altitudes up to 1000 m and up to 2000 m in southwestern China. P. aurea is frost hardy, and will tolerate up to -10(-18)ºC. It grows best on rich, deep and well-drained sandy soils. In Indonesia it mostly grows in the highlands above 700 m altitude but plants grown in the lowland have shorter and smaller culms. In the Philippines it grows very well in Baguio at 1500 m altitude with average temperatures of 18-26ºC. Because P. aurea has a leptomorph rhizome system, it can be an invasive bamboo if not well controlled.

P. aurea can be propagated by seed and by clump division. Because seed is rarely available, the normal propagation method is by clump division. Clump parts, 0.5-1.0 m long are taken, having a rhizome, roots and 1-several culm parts. They are planted in previously prepared holes, enriched with organic manure. Preservation of culms has been tried using cold soaking treatment. Boron penetration after an immersion period of 5 days was about 93% for split and 79% for unsplit culm parts.

Genetic resources and breeding
No germplasm collections are available for P. aurea, but it is present in many botanical gardens. There are no known breeding programmes.

The future of P. aurea as ornamental plant, especially in temperate climates, is promising. For South-East Asia P. aurea remains of interest in the production of souvenir articles. Germplasm collections are urgently needed. More research is needed to develop cultivation methods and specific cultivars.

Chu Chengde and E.A. Widjaja

For additional information about author(s) see Contributors or Editors.