2. Thyrsostachys siamensis Gamble, Ann. Roy. Bot. Gard. Calcutta. 7: 59. 1896.
泰竹 tai zhu
Bambusa regia Thomson ex Munro, nom. rej.; Thyrso-stachys regia (Thomson ex Munro) Bennet, nom. rej.
Culms to 12 m, to 6 cm in diam.; internodes initially green, becoming gray-green, 20–30 cm; wall thick; nodes slightly thickened, with a white ring below. Branches several, main mid-culm ones to 1 cm in diam. Culm sheaths pale brown, 3/4–1 × as long as internodes, papery, appressed pubescent, margins ciliate, apex truncate; ciliate; auricles small; ligule ca. 1 mm; blade erect, base ca. 3/4 width of sheath apex. Leaf sheaths white pubescent and ciliate; ligule very short, pubes-cent; blade linear, 7.5–15 × 0.7–1.2 cm. Pseudospikelets 1.2–1.4 cm; prophylls to 0.8 cm; gemmiferous bracts 2 or 3; glumes 2 or 3; fertile florets 1–3. Fertile lemma 1–1.3 cm; palea slightly longer than lemma, narrow, bifid for 1/3 of its length; lodicules absent to 3. Anthers pale yellow, apex purple, apiculate. Ovary ovoid to turbinate; style 1, ca. 1.2 cm; stigmas 1–3. Caryopsis ca. 0.6 cm. 2n = 76*.
River valleys to hilly forested areas; 500–1000 m. S Yunnan [Myanmar, N Thailand].
This species is one of the most beautiful ornamental bamboos in the tropics of SE Asia, long cultivated in SE China, and recently found wild in Yunnan. The widespread use and economic importance of the name Thyrosostachys siamensis justified its conservation against the earlier name, Bambusa regia (1868).