倭竹 wo zhu

Bambusa kumasaca Zollinger ex Steudel, Syn. Pl. Glumac. 1: 331. 1854; B. ruscifolia Siebold ex Munro; Phyllo-stachys kumasaca (Zollinger ex Steudel) Munro; Shibataea ruscifolia (Siebold ex Munro) Makino.

Culms ca. 1 m, 3–4 mm in diam.; internodes glossy, glabrous; wall thick with small lumen; nodes with ridge strongly raised; intranode to 3–5 mm. Culm sheaths papery, appressed pubescent, outer margin ciliate; auricles absent; oral setae few or absent; ligule truncate or arcuate, to 3–4 mm, pubescent, apex ciliolate; blade lanceolate, small. Branches 3–5(or 6) per node, 0.5–1.5 cm, equal in diam., 2–4(–6)-noded, axillary prophyll usually persistent; branch sheaths gradually deciduous or persistent and disintegrating in situ, membranous. Leaves 1(or 2) per ultimate branch; blade adaxially deep green, ovate or narrowly ovate, 2.5–18 × 0.6–3.5 cm, abaxially glaucous and pubescent, adaxially glabrous, secondary veins 6–9-paired, tessellations rectangular, base broadly cuneate to rounded, apex acuminate. Flowering branches at lower nodes of leafy branches or rarely at nodes of culms, usually rebranched, secondary branches comprising a prophyll, few bracts, and (1 or)2–5 pseudospikelets; pseudospikelets consisting of a prophyll, 0 or 1 empty bract, 2 or 3 gemmiferous bracts, and a terminal spikelet. Spikelets with 3–7 florets, lower 1–3 bisexual, others male or sterile. Lemma thin; palea membranous; lodicules thinly membranous, ovate. Anthers yellow. Ovary narrowly ovoid; style 1; stigmas 2 or 3. Caryopsis narrowly ovoid. New shoots May–Jun. 2n = 48*.

* Mountain slopes. Fujian, Zhejiang; cultivated in Anhui, Guangdong, Jiangsu, and Taiwan [widely cultivated in Japan].

The specific epithet has been erroneously spelled "kumasa" by some authors.

A cultivar with yellow-striped leaves, Shibat'a kumasaca 'Aureostriata', is grown. The species is introduced in many countries as an ornamental.