Chimonobambusa Makino
Including Oreocalamus Keng, Qiongzhuea Hsueh & Yi
Habit, vegetative morphology. Perennial; rhizomatous, or stoloniferous. The flowering culms leafy. Culms 50–600 cm high; woody and persistent (monopodial); to 3 cm in diameter; branched above. Primary branches/mid-culm node 3 (these subsequently giving rise to multiple twigs). Culm sheaths deciduous in their entirety (somewhat leathery, with very small blades). Culm internodes hollow. Rhizomes leptomorph. Plants conspicuously armed (the two-ridged culm nodes usually thorny). Leaves not basally aggregated; with auricular setae. Leaf blades broad, or narrow; pseudopetiolate; cross veined, or without cross venation; disarticulating from the sheaths; rolled in bud.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence indeterminate (as indicated by bracts subtending the spikelets); seemingly without pseudospikelets; exhibiting 1–12 spikelets at each node of leafy or leafless branches; non-digitate; spatheate; a complex of ‘partial inflorescences’ and intervening foliar organs (inflorescence branches with or without foliage leaves). Spikelet-bearing axes ‘racemes’, or paniculate; persistent. Spikelets not secund; sessile.
Female-fertile spikelets. Spikelets disarticulating above the glumes; disarticulating between the florets (?); with distinctly elongated rachilla internodes between the florets (‘the florets distant’). Rachilla prolonged beyond the uppermost female-fertile floret (?); the rachilla extension with incomplete florets. Hairy callus absent.
Glumes two to several; very unequal; shorter than the adjacent lemmas; awnless. Lower glume 3 nerved. Upper glume 7 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped.
Female-fertile florets 2–8 (?). Lemmas ovate, membranous; entire; pointed; awnless; 8 nerved. Palea present; relatively long; entire; several nerved (7 observed); 2-keeled. Lodicules present; 3; free; membranous; ciliate; not toothed; heavily vascularized. Stamens 3. Anthers without an apically prolonged connective. Ovary glabrous; without a conspicuous apical appendage. Styles free to their bases (apparently). Stigmas 2 (feathery).
Fruit, embryo and seedling. Fruit not grooved; not noticeably compressed. Hilum short. Pericarp fleshy (at least, in Subg. Oreocalamus and Quiongzhuea); free. Seed ‘non-endospermic’.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present; costal and intercostal. Intercostal papillae conspicuously over-arching the stomata; several per cell (mostly one row per cell, of the coronate-pit type, cf. Poa helmsii). Long-cells similar in shape costally and intercostally; of similar wall thickness costally and intercostally. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type (but large and fat); (54–)63–69 microns long (in C. densifolia); 6–9 microns wide at the septum. Microhair total length/width at septum 6–11.5 (i.e. very variable in C. densifolia). Microhair apical cells (21–)24–27 microns long. Microhair apical cell/total length ratio 0.35–0.43. Stomata common; about 27 microns long (in C. densifolia). Subsidiaries non-papillate; parallel-sided to dome-shaped. Intercostal short-cells common; not paired (mostly solitary); not silicified (mostly). Costal short-cells neither distinctly grouped into long rows nor predominantly paired (ones and twos). Costal silica bodies saddle shaped and oryzoid.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; without adaxial palisade; with arm cells; with fusoids. The fusoids external to the PBS. Leaf blade with the ribs more or less constant in size. Midrib conspicuous (a larger bundle, with massive I-configuration of girders); with one bundle only. Bulliforms present in discrete, regular adaxial groups; in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with all the bundles); forming ‘figures’ (all narrow I’s, except midrib). Sclerenchyma all associated with vascular bundles.
Cytology. Chromosome base number, x = 12. 2n = 48. 4 ploid. Chromosomes ‘small’.
Taxonomy. Bambusoideae; Bambusodae; Bambuseae.
Distribution, ecology, phytogeography. 10 species; eastern Asia and Himalaya.
Holarctic and Paleotropical. Boreal. Indomalesian. Eastern Asian. Indian and Indo-Chinese.
Rusts and smuts. Rusts — Stereostratum. Taxonomically wide-ranging species: Stereostratum corticoides.
References, etc. Morphological/taxonomic: Chao and Renvoize 1989. Leaf anatomical: this project.
Special comments. Fruit data wanting.
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).