Clumps rhizomatous; stems tufted, erect, mostly 6 to 12 ft high in cultivation (up to 20 or 30 ft high in the wild state), round when young and small, but distinctly four-sided when 1⁄2 in. or more thick (up to 11⁄4 in. thick in the wild state), rounded at the corners, thick-walled, with rather long internodes, rough, green, becoming brownish green; joints prominent, the lower bearing spine-like outgrowths or only aculeate; branches three from each joint, much divided and very slender; stem-sheaths firm, hairless. Leaf-blades narrowly lanceolate, acuminate, 4 to 8 in. long, 1⁄2 to 1 in. wide, rich green, minutely hairy when young, rough on both margins, with eight to fourteen pairs of secondary veins, tessellate.
Native of China and Formosa; introduced about 1892. This very distinct bamboo is, unfortunately, not very hardy, and is killed to the ground at Kew during all but the mildest winters, although never outright. It is, no doubt, admirably adapted for the south-western counties, where its remarkable quadrangular stems and generally ornamental character would make it well worth cultivation. It runs freely, even at Kew, where the top growth is so frequently killed.