| # The grass genera of the world |

L. Watson, T.D. Macfarlane, and M.J. Dallwitz

### Sasa Makino & Shibata

From a Japanese word for small bamboos.

Including Neosasamorpha Tatewaki, Nipponobambusa Muroi, Sasaella Mak., Sasamorpha Nakai

Habit, vegetative morphology. Small to medium, shrubby perennial. The flowering culms leafy. Culms 100–400 cm high; woody and persistent; branched above (usually), or unbranched above. Buds from which the primary culm branches arise (consistently) 1. Primary branches 1 (nearly always), or 3 (very rarely); when 3, horizontally aligned. The branching dendroid, or suffrutescent (mostly). Culm leaf sheaths present; deciduous, or persistent; conspicuously auriculate, or not conspicuously auriculate. Culm leaves with conspicuous blades. Culm internodes hollow. Rhizomes leptomorph. Plants unarmed. Leaves not basally aggregated; with auricular setae. Leaf blades broadly lanceolate, or elliptic (large); broad (acuminate); pseudopetiolate; cross veined; where recorded, disarticulating from the sheaths; rolled in bud. Ligule an unfringed membrane. Contra-ligule consistently absent.

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets.

Inflorescence. Inflorescence determinate; without pseudospikelets; paniculate; open; spatheate (the long peduncle covered by sheaths); a complex of ‘partial inflorescences’ and intervening foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.

Female-fertile spikelets. Spikelets linear (commonly), or oblong, or lanceolate; compressed laterally; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets.

Glumes present; two; shorter than the adjacent lemmas; similar (scarious). Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped. Spikelets without proximal incomplete florets.

Female-fertile florets 3–13. Lemmas decidedly firmer than the glumes (with tessellate venation); not becoming indurated; non-carinate; more than 5-nerved. Palea present; not convolute; 2-keeled. Lodicules present; 3; free. Stamens 6. Ovary apically glabrous; where known, without a conspicuous apical appendage. Styles fused. Stigmas 3 (plumose).

Fruit, embryo and seedling. Fruit longitudinally grooved. Endosperm containing compound starch grains.

Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present (abundant); costal and intercostal (present over minor bundles, lacking over the large ones). Intercostal papillae over-arching the stomata (and largely obscuring them); several per cell (large, circular, thick walled and refractory, a single row per cell). Mid-intercostal long-cells rectangular; having markedly sinuous walls (the sinuosity fairly fine, even). Microhairs present; elongated; clearly two-celled (the basal cells very long); panicoid-type. Stomata common. Subsidiaries papillate; dome-shaped. Intercostal short-cells not apparent in this highly papillate epidermis. With costal and intercostal, scattered prickles. Costal short-cells conspicuously in long rows. Costal silica bodies present and well developed; saddle shaped (large).

Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with adaxial palisade; with arm cells; with fusoids. The fusoids external to the PBS. Leaf blade adaxially flat. Midrib conspicuous; having complex vascularization. The lamina symmetrical on either side of the midrib. Bulliforms present in discrete, regular adaxial groups; in simple fans (these large). All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with all the bundles); forming ‘figures’ (I’s and T’s). Sclerenchyma all associated with vascular bundles.

Cytology. Chromosome base number, x = 12. 2n = 48 (sample including Sasamorpha and Sasaella). 4 ploid. Chromosomes ‘small’.

Classification. Watson & Dallwitz (1994): Bambusoideae; Bambusodae; Bambuseae. Soreng et al. (2015): Bambusoideae; Arundinarodae; Arundinarieae (including Sasaella, Sasamorpha); Arundinariinae. About 50 species.

Distribution, phytogeography, ecology. Eastern Asia.

Hybrids. May hybridize with Semiarundinaria (×Hibanobambusa Maruyama and Okamura).

Rusts and smuts. Rusts — Stereostratum and Puccinia. Taxonomically wide-ranging species: Stereostratum corticoides, Puccinia longicornis, and Puccinia kusanoi. Smuts from Ustilaginaceae. Ustilaginaceae — Ustilago.

References, etc. Leaf anatomical: studied by us - Sasa kurilensis (Rupr.) Makino & Shibata.

Special comments. Fruit data wanting.

Illustrations. • Sasa borealis (as S. spiculosa and S. purpurascens: Camus Fig. 1, 1913). • abbreviations for Camus (1913) figures. • Sasa paniculata (cf. S. senanensis), S. palmata and S. chartacea (as vars. ontakensis and nana: Camus Fig. 2, 1913). • Sasa kurilensis (as Arundinaria): Hooker's Ic. Pl. 20 (1891). • Sasa kurilensis, abaxial epidermis of leaf blade: this project.

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, and classifications. See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., Macfarlane, T.D., and Dallwitz, M.J. 1992 onwards. The grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. Version: 15th June 2025. delta-intkey.com’.

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