The grass genera of the world
Including Klemachloa Parker, Neosinocalamus Keng f., Sinocalamus McClure
Excluding Gigantochloa, Oreobambos, Oxytenanthera
Habit, vegetative morphology. Perennial; caespitose. The flowering culms leafy. Culms 600–4000 cm high (D. giganteus being probably the tallest grass); woody and persistent; to 30 cm in diameter; branched above. Buds from which the primary culm branches arise infrequently recorded, 1, or 3. Primary branches 4–20. The branching dendroid (to suffrutescent only in D. minor). Culm nodes glabrous. Culm leaf sheaths present; deciduous (usually), or persistent; not leaving a persistent girdle; usually conspicuously auriculate. Culm leaves with conspicuous blades. Culm leaf blades linear, or lanceolate, or ovate, or triangular. Culm internodes solid, or hollow. Pluricaespitose. Rhizomes pachymorph. Plants unarmed. Young shoots intravaginal. Leaves not basally aggregated; auriculate (but usually inconspicuously so). Leaf blades broad; pseudopetiolate; without cross venation (but often with pellucid glands); disarticulating from the sheaths; rolled in bud. Ligule present; 3 mm long. Contra-ligule present (D. cinctus only), or absent.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. Not viviparous.
Inflorescence. Inflorescence indeterminate; with pseudospikelets; usually comprising spikes of spikelet tufts; espatheate. Spikelet-bearing axes very much reduced and paniculate, or very much reduced and capitate. Spikelets unaccompanied by bractiform involucres, not associated with setiform vestigial branches.
Female-fertile spikelets. Spikelets unconventional; 8–20 mm long; elliptic, or lanceolate, or ovate; not noticeably compressed. Rachilla prolonged beyond the uppermost female-fertile floret; hairless.
Glumes two, or several (?); relatively large; very unequal to more or less equal; shorter than the adjacent lemmas; pointed, or not pointed (ovate, acute or mucronate); awnless; non-carinate; similar. Lower glume longer than half length of lowest lemma; 17 nerved (in material seen). Upper glume 19 nerved (in material seen).
Female-fertile florets 2–8. Lemmas similar in texture to the glumes; not becoming indurated; entire; pointed; awnless, or mucronate (?); hairless; non-carinate; without a germination flap; 29 nerved. Palea present; relatively long; not convolute; entire, or apically notched, or deeply bifid; awnless, without apical setae; not indurated; several nerved (13 observed); 2-keeled (in lower florets), or keel-less (in upper florets). Lodicules absent (or very scarce). Stamens 6; with free filaments, or monadelphous. Anthers 2.5–5 mm long, or 7–10 mm long (in D. giganteus); penicillate, or not penicillate; with the connective apically prolonged. Ovary apically hairy; with a conspicuous apical appendage, or without a conspicuous apical appendage. The appendage when present, broadly conical, fleshy. Styles fused. Stigmas 1(–3); red pigmented.
Fruit, embryo and seedling. Fruit free from both lemma and palea; small to medium sized. Hilum long-linear. Pericarp thick and hard (crustaceous or hardened); free. Embryo not visible. Endosperm hard; containing compound starch grains. Embryo with an epiblast; with a scutellar tail; with a negligible mesocotyl internode; with more than one scutellum bundle. Embryonic leaf margins overlapping.
First seedling leaf without a lamina.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present; costal and intercostal. Intercostal papillae over-arching the stomata (sometimes conspicuously so), or not over-arching the stomata; several per cell. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type; 48–51(–57) microns long (in D. giganteus); 4.5–7.5 microns wide at the septum. Microhair total length/width at septum 7.6–10.7. Microhair apical cells 24–25.5(–30) microns long. Microhair apical cell/total length ratio 0.47–0.53. Stomata common; 22.5–27 microns long. Subsidiaries non-papillate; high dome-shaped and triangular. Guard-cells overlapped by the interstomatals. Intercostal short-cells common, or absent or very rare. Costal short-cells conspicuously in long rows, or predominantly paired, or neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies saddle shaped, or tall-and-narrow, or oryzoid.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; with adaxial palisade; with arm cells; with fusoids. The fusoids external to the PBS. Leaf blade nodular in section to adaxially flat; with the ribs more or less constant in size (low), or with the ribs very irregular in sizes. Midrib conspicuous; having complex vascularization. Bulliforms present in discrete, regular adaxial groups; in simple fans (sometimes large-celled, Zea-type). All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming figures.
Cytology. Chromosome base number, x = 12. 2n = 48, 64, and 72 (rarely 70). 4, 5, and 6 ploid.
Classification. Watson & Dallwitz (1994): Bambusoideae; Bambusodae; Bambuseae. Soreng et al. (2015): Bambusoideae; Bambusodae; Bambuseae (including synonyms); Bambusinae. About 35 species.
Distribution, phytogeography, ecology. China, Indomalayan region.
Economic aspects. Significant weed species: D. giganteus. D. strictus, with solid culms, is a very important timber species; others (e.g. D.asper, D. latiflorus) have edible shoots; and splits of several species are used for weaving baskets etc.
Rusts and smuts. Rusts Dasturella. Taxonomically wide-ranging species: Dasturella divina.
References, etc. Leaf anatomical: Metcalfe 1960; studied by us - D. gigantus Munro.
Illustrations. • D.sericeus and D. hamiltonii: Camus (1913). • Abbreviations for Camus (1913) figures. • D. giganteus and D. asper (as flagellifer): Camus (1913). • D. giganteus, abaxial epidermis of leaf blade: this project. • D. giganteus, Leaf blade TS: 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: 11th December 2017. delta-intkey.com/grass’.