Bambusa polymorpha

Bambusa polymorpha is a large, woody bamboo in the grass family, Poaceae. Its common names include Burmese bamboo and Jama Betua. Its native range runs from northeastern India through Bangladesh, Myanmar and Thailand to Yunnan in China. It grows in wet tropical regions. In the wild, it thrives in humid mixed deciduous forest. It favours lower slopes and valleys where water drains well.

This bamboo forms clumps and grows fast. PFAF gives a garden size of 39 feet (12 metres) tall. It lists a spread of 26 feet (8 metres). Useful Tropical Plants reports taller plants, reaching 49–82 feet (15–25 metres). The upright culms bend outward near their tops. They can reach about 0.5 feet (0.15 metres) across. Their grey-green surface bears pale, whitish-brown hairs. Cut stems turn brown-green as they dry. Plants keep their leaves in moist sites but may shed them during dry spells.

Light shade suits this species best, though it also accepts full sun. It prefers deep, rich loam that drains well and stays moist. PFAF also lists sandy and clay soils as suitable. The preferred soil pH is 5–6, with tolerance from 4.5 to 6.5. Warm days of 22–28°C suit it best. Its preferred annual rainfall is 1,200–2,500 millimetres. PFAF lists USDA zones 9–12. Plants tolerate strong winds, but not salt-laden coastal exposure.

Wind carries the pollen. Plants may grow for many years between flowering events. This long wait makes seed hard to obtain. Growers can raise plants from seed or divide clumps when growth starts. Young seedlings need light shade and compost that does not dry out. Growers also plant this bamboo for its form and useful stems. It has a place in food forests and biomass plantings.

The culms supply material for walls, floors, roofs, mats and crafts. They also provide pulp for paper and board. Harvested stems have poor natural durability. Termites, fungi and borers can ruin untreated, exposed culms within 19 months. Traditional preparation involves soaking cut culms in flowing water, then drying them in air. People eat the young shoots, harvesting them as they break through the soil. Reports differ on flavour: some describe sweet shoots, while others find them bitter. Both PFAF and Useful Tropical Plants report no known hazards. PFAF records no known medicinal uses.