2018 Volume 93 Issue 5 Pages 307-316
Usefulness of morphology of axillary buds as a stable character to distinguish genera and sections of the Japanese dwarf bamboos (the Sasa-group, Arundinariinae, Arundinarieae, Bambusoideae, Poaceae) was tested through detailed observation and comparison among genera and sections (including those of intergeneric/intersectional hybrid origin), with special notice to width and hairiness of wings developed on lateral keels of a prophyll enclosing the bud. The morphological characters of axillary buds in each genus and section can be categorized as follows: rhombic-ovate in the genus Sasa, ovate in Pleioblastus, narrowly ovate in Sasamorpha, lanceolate in Pseudosasa. In Neosasamorpha, buds of basal nodes show the Sasa-type, while those of apical nodes show the Sasamorpha-type. Buds of Sasaella are narrowly triangular-ovate, i.e., Pleioblastus/Sasa intermediate type. In the genus Sasa, marginal wings of prophyll are linear, distally sparsely ciliate in the sect. Macrochlamys, gradually broadened and projected toward apex in the sect. Monilicladae, evenly wide throughout the length in the sect. Sasa, evenly developed throughout the length, gradually broadened distally and projected at the apices in the sect. Crassinodi. Marginal wings for other genera are evenly developed, sparsely ciliate throughout widened toward apex in Sasamorpha, more or less projected on both sides, surface and margins appressed-lanulose in Pleioblastus, very narrow with spreading cilia evenly distributed along margins in Pseudosasa japonica. An intergeneric hybrid between Pseudosasa and Pleioblastus and a few intersectional hybrid complexes in the genus Sasa were also investigated. These results suggest that the shape of axillary bud with prophyll features provides useful diagnostic characters for the Japanese Arundinariinae.
