Stems round, slender, solid, erect, 3 to 5 ft high; purplish green, from 1⁄8 to 1⁄4 in. thick at the base, almost hidden the first season by the clasping, persistent sheaths, which are at first purplish, mottled conspicuously with pinkish grey, turning grey-white with age. Branches erect, normally three at each joint, forming a dense but elegant, cylindrical mass of foliage; the branches, however, do not develop until the second year, the tops of the slender, whip-like, leafless stems of the first year standing out above the mass of foliage throughout the winter. Leaves bright green, 2 to 5 in. long, 3⁄8 in. to 1⁄2 in. wide, with slender, awl-like points; four or five secondary nerves each side the midrib; margins set with minute bristles; leaf-sheath terminated by a tuft of pale curly bristles and edged with small hairs.
Native of Japan; introduced to Ireland in 1889. A very pretty, well-marked bamboo, distinguished by the marbled stem-sheaths, the stems remaining unbranched the first season, the absence of a pipe or hollow up the centre, and by the apex of the leaf being constricted about 1⁄2 in. from the tip. It spreads very rapidly by underground suckers, forming luxuriant masses, but is liable to injury by winter cold.
Flowering has been observed in most years on a few stems in well-established clumps, the first recorded being in 1909; the dark purple ovaries and developing seeds are exposed and protrude between the gaping lemma and palea, but soon fall.
cv. 'Variegata'. – Leaves variegated with white; cultivated in Japan (Chimonobambusa m. cv. Variegata Ohwi; C. m. var. variegata Makino).