Flora of Barro Colorado Island

Bambusa arundinacea

Retz., Obs. Bot. 5:24.1789.

Erect bamboo to 20 (25) m tall; culms olive-green, shiny, 11-12 cm diam, erect to broadly arching, densely rooting at lower nodes, occurring in congested clumps of ca 4 m or more in diameter; internodes mostly 10-25 cm long near the base, the basal ones thick-walled (to ca 1 cm thick); nodes with a conspicuous leaf-sheath scar and with many stout branches to 3 cm diam, soon becoming slender, usually l- or 2-branched,            wide-spreading, form­ing a tangled mass to 5 m high, heavily armed at the nodes, the spines to 1.5 cm long; branch apices also spine­-like; sheath blades broadly triangular, appressed (reflexed at upper nodes); branches on main culm to 2 m or more long, their axes flexuose, the nodes with a prominent ring-­like sheath scar and often with stout spines, the spines often weakly curved, with short internodes; the lower 1.5 cm of the base of each branch encircled by several short sheathlike bracts, the smaller leafy branches with leaves clustered mostly toward their apices. Sheaths glabrous except often short-pubescent along upper margin, trun­cate to auriculate at apex, often bearing a few, thick, usually deciduous trichomes; leaf blades linear-lanceolate, acuminate, (2.5) 7-15 (20) cm long, (5) 8-18 (25) mm wide, glabrous or with a few long trichomes near base on upper surface, glabrous or puberulent on lower surface. Inflo­rescences not seen. Croat 17038.

Cultivated in the Laboratory Clearing northwest of the dining hall.

Native to India; introduced occasionally in other tropi­cal areas of the world.