Schizostachyum Nees
From the Greek schistos (cleft) and stachys (‘ear of corn’, spike), referring to spacing of spikelets.
Including Leptocanna Chia & Fung
Excluding Cephalostachyum, Dendrochloa, Pseudostachyum, Teinostachyum
Habit, vegetative morphology. Perennial (the young culm internodes uniformly covered with adpressed white hairs). The flowering culms leafy. Culms 400–1200 cm high; woody and persistent; to 5 cm in diameter; scandent, or not scandent. Primary branches/mid-culm node several to many. Culm internodes solid, or hollow. Rhizomes pachymorph. Plants unarmed. Young shoots extravaginal. Leaves not basally aggregated; auriculate (the auricles sometimes small, often bristly); with auricular setae (curved). Sheath margins free. Leaf blades broad; 15–90 mm wide (15–50 cm long); pseudopetiolate; cross veined (and often with pellucid dots or dashes), or without cross venation; disarticulating from the sheaths; an unfringed membrane, or a fringed membrane.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence indeterminate; with pseudospikelets; a false spike, with spikelets on contracted axes, or paniculate (with alternate clusters of pseudospikelets in terminal spike-like or paniculate inflorescences, which are leafless or leafy below); spatheate; a complex of ‘partial inflorescences’ and intervening foliar organs. Spikelet-bearing axes spikelike, or paniculate; persistent. Spikelets not secund.
Female-fertile spikelets. Spikelets 12–50 mm long; compressed laterally to not noticeably compressed (subterete); disarticulating above the glumes; disarticulating between the florets. Rachilla usually prolonged beyond the uppermost female-fertile floret (with a rudimentary floret); the rachilla extension with incomplete florets.
Glumes present, or absent (depending on interpretation); if considered present, one per spikelet to several (3 or 4 ‘bracts’ with buds, in lieu of glumes). 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 1, or 3, or 4. Lemmas similar in texture to the glumes; awned (shortly spine-tipped), or awnless to mucronate (apiculate, with overlapping and convoluted margins). Awns when present, 1; apical; much shorter than the body of the lemma (to 3 mm long). Lemmas non-carinate; 11–17 nerved (in material seen). Palea present; relatively long (usually exceeding the lemma); not convolute; apically notched; shortly 2-pointed; several nerved (11–15 in material seen); 2-keeled (grooved between them, to accommodate the rachilla). Lodicules present, or absent (sometimes exhibiting transitions between stamens and lodicules); when present, 1–10; free; membranous; ciliate. Stamens usually 6; usually with free filaments. Anthers 5–14 mm long; penicillate, or not penicillate; with the connective apically prolonged, or without an apically prolonged connective. Ovary glabrous; with a conspicuous apical appendage. The appendage long, stiff and tapering. Styles fused (the single style hollow). Stigmas 3 (simple); white, or red pigmented.
Fruit, embryo and seedling. Fruit compressed laterally. Hilum long-linear. Pericarp thick and hard (leathery to crustaceous); free. Embryo small.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present (costally and intercostally). Intercostal papillae over-arching the stomata (and completely obscuring them); several per cell (large, one row per long-cell). Long-cells similar in shape costally and intercostally; of similar wall thickness costally and intercostally (walls of medium thickness). Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type; (54–)57–63(–69) microns long; (8.4–)9 microns wide at the septum. Microhair total length/width at septum 6–7.7. Microhair apical cells (28–)30–36(–39) microns long. Microhair apical cell/total length ratio 0.53–0.57. Stomata common (outlines obscured by papillae); 19.5–21–24 microns long. Intercostal short-cells common; in cork/silica-cell pairs; silicified. Intercostal silica bodies tall-and-narrow. Crown cells present (at least, having large umbonate or tiny-pointed ‘prickles’). Costal short-cells predominantly paired. Costal silica bodies rounded, or saddle shaped, or tall-and-narrow, or crescentic, or oryzoid (predominantly tall-and-narrow, overlapping into ovals, crescents and near-oryzoids); not sharp-pointed.
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 (save alongside the midrib). Midrib conspicuous; having complex vascularization. Bulliforms present in discrete, regular adaxial groups; in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’ (the larger bundles). Sclerenchyma all associated with vascular bundles.
Taxonomy. Bambusoideae; Bambusodae; Bambuseae.
Distribution, ecology, phytogeography. 35 species; eastern Asia. Halophytic (S. pulchellum), or glycophytic. Mostly savanna, rarely coastal sand.
Paleotropical. Indomalesian. Indo-Chinese and Malesian.
Economic importance. Pliant, tough splints of S. dumetorum constitute thonging, and the whole culms are pounded and twisted into ropes. S. jaculans is the blowpipe bamboo of lowland Malaya.
References, etc. Leaf anatomical: Metcalfe 1960; this project.
Cite this publication as: Watson, L., and Dallwitz, M. J. (1992 onwards). ‘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.’ http://biodiversity.uno.edu/delta/. Version: 18th August 1999. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993 onwards, 1998), and Watson and Dallwitz (1994), and Watson, Dallwitz, and Johnston (1986) should also be cited (see References).