In November 1989 two clumps of Thyrsostachys regia (Munro) Bennet (T. siamensis Kurz ex Gamble) flowered in Bangladesh Forest Research Institute Bambusetum, Chittagong. Flowering was of gregarious type and the clumps died after flowering. Floral buds bloomed after 4-5 weeks of their initiation. There are two florets in a spikelet and the flowers are protandrous. Anthesis generally occurred in the morning and occasionally in the afternoon. Anther dehiscence started at noon and continued for the whole afternoon. When in full bloom two bee species (Apis dorsata and an unidentified one) were found to visit the flowers. Fruits matured after 60-70 days of blooming. Squirrels and three bird species, Lonchura punctulata, L. striata andL. malabarica) were found to feed on matured seeds.