Plants small to shrub-like, spreading widely and forming very dense extensive stands; rhizomes leptomorph, tillering. Culms 0.3–3 m, 0.2–1 cm in diam., pluricespitose; nodes level or prominent; internodes terete, not grooved. Branches usually 1, subequal to the culm in diam., occasionally 3 at the upper nodes; buds initially closed at front, prophyll 2-keeled. Culm sheaths very persistent; blade lanceolate. Leaf sheaths persistent; blade often large, venation tessellate, margins withered pale brown in winter, arrangement regular and rather palmate. Synflorescence paniculate. Spikelets pedicellate; glumes 2; florets several; stamens 6; style branches 3. x = 12. Name from zasa, a Japanese name for smaller bamboos.
As interpreted here, Sasa is a genus of approximately 70 species, distinguished from other temperate bamboos in the possession of 6 rather than 3 stamens, but also by having a palmate leaf arrangement. Most species are native to Japan, with some found in China and Korea. They are efficient groundcover plants with very dense foliage, and can be invasive and persistent, but many have attractive foliage in winter, the leaves developing contrasting pale margins. Synonymy within Sasa is very extensive indeed, with many names published in Japan from 1900–1945 on the basis of differences that are very hard to see, followed by movement of varieties between species, and species between small genera. Some species have as many as 80 synonyms. For full synonymy see Suzuki, 1978, & Ohrnberger, 1999.
The smallest species such as Sasa ramosa are often placed in Sasaella, and originated as hybrids between Sasa and Pleioblastus. They are distinguished largely by the challenging determination of the position of scabrosity on the oral setae. They can run very widely and are not recommended. Sasamorpha (and Neosasamorpha) are even harder to separate from Sasa and rare in cultivation.
Ohrnberger, D. (1999). The Bamboos of the World: 82–119.
Suzuki, S. (1978). Index to Japanese Bambusaceae. Gakken, Tokyo.