Bambusa Schreber
Latinised from Malay vernacular bambu.
Including Arundarbor Kuntze, Bonia Balansa, Criciuma Soderstrom & Londoño, Dendrocalamopsis (Chia & Fung) Keng f., Eremocaulon Soderstrom & Londoño, Guadua Kunth, Holttumochloa K.M. Wong, Ischurochloa Büse, Kinabaluchloa K.M. Wong, Leleba Nakai, Lingnania McClure, Maclurochloa K.M. Wong, Soejatmia K.M. Wong, and Tetragonocalamus Nakai
Habit, vegetative morphology. Perennial. The flowering culms leafless, or leafy. Culms (200–)500–3500 cm high; woody and persistent; to 15 cm in diameter; scandent, or not scandent; branched above. Culm nodes glabrous. Primary branches/mid-culm node 3–30 (several to many). Culm internodes hollow (sometimes nearly solid). Pluricaespitose. Rhizomes pachymorph. Plants conspicuously armed (with thorns from the nodes: Guadua), or unarmed. Leaves not basally aggregated; auriculate; with auricular setae, or without auricular setae. Leaf blades broad, or narrow (small to moderate-sized); pseudopetiolate; cross veined, or without cross venation; disarticulating from the sheaths; rolled in bud; an unfringed membrane to a fringed membrane; short or long. Contra-ligule present.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. Not viviparous.
Inflorescence. Inflorescence indeterminate; with pseudospikelets; of pseudospikelets, these solitary or in tufts, fascicles or capitula on leafless branches; open; spatheate (with or without foliage leaves); a complex of ‘partial inflorescences’ and intervening foliar organs. Spikelet-bearing axes very much reduced, or paniculate to capitate; persistent. Spikelets not secund.
Female-fertile spikelets. Spikelets 10–80 mm long; compressed laterally to not noticeably compressed; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; hairless. Hairy callus absent.
Glumes (i.e. transitional, empty glumes, which are additional to bud-bearing basal bracts) present; one per spikelet to several (1–3); very unequal, or more or less equal; shorter than the spikelets; shorter than the adjacent lemmas; hairless; not pointed; awnless; carinate; similar. Lower glume longer than half length of lowest lemma; 7–18 nerved. Upper glume 7–18 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets, or both distal and proximal to the female-fertile florets. The distal incomplete florets merely underdeveloped. The proximal incomplete florets 0–3 (? - fewer than 4); sterile. The proximal lemmas awnless; several-nerved; exceeded by the female-fertile lemmas; similar in texture to the female-fertile lemmas.
Female-fertile florets (1–)2–20 (-‘many’). Lemmas similar in texture to the glumes; not becoming indurated; entire; blunt; awnless (usually), or mucronate (Guadua); hairless; carinate to non-carinate; 9–22 nerved. Palea present; relatively long; entire to apically notched; awnless, without apical setae; not indurated; several nerved (about 6–16); 2-keeled. Palea keels winged (Guadua), or wingless. Lodicules present; 3; free; membranous; ciliate; not toothed; heavily vascularized. Stamens 6. Anthers 3.5–8 mm long; penicillate, or not penicillate; with the connective apically prolonged, or without an apically prolonged connective. Ovary hairy; with a conspicuous apical appendage. The appendage broadly conical, fleshy (except in Guadua? - see illustration in Londoño and Peterson 1992). Styles fused. Stigmas 3 (usually?).
Fruit, embryo and seedling. Fruit free from both lemma and palea; longitudinally grooved; not noticeably compressed; with hairs confined to a terminal tuft. Hilum long-linear. Pericarp thin. Embryo small; not waisted. Endosperm containing compound starch grains. Embryo with an epiblast.
First seedling leaf without a lamina.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present. Intercostal papillae over-arching the stomata; several per cell. Long-cells similar in shape costally and intercostally; differing markedly in wall thickness costally and intercostally. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type; 36–48 microns long (in B. arnhemica); 6–9 microns wide at the septum. Microhair total length/width at septum 4.5–8 (i.e. very variable, in B. arnhemica). Microhair apical cells 15–21 microns long. Microhair apical cell/total length ratio 0.37–0.46. Stomata common; 21–27 microns long. Subsidiaries parallel-sided, or dome-shaped, or triangular; including both triangular and parallel-sided forms on the same leaf. Intercostal short-cells common; in cork/silica-cell pairs. Costal short-cells conspicuously in long rows. Costal silica bodies saddle shaped, or oryzoid.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; with arm cells; with fusoids. Leaf blade adaxially flat. Midrib conspicuous; having complex vascularization. The lamina distinctly asymmetrical on either side of the midrib. Bulliforms present in discrete, regular adaxial groups; in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’.
Culm anatomy. Culm internode bundles in three or more rings.
Phytochemistry. Leaves without flavonoid sulphates (1 species).
Special diagnostic feature. The inflorescences not as in Atractantha (q.v.).
Cytology. Chromosome base number, x = 12. 2n = 46 (Guadua), or 24, 48, 70, and 72. 4 and 6 ploid (rarely diploid). Chromosomes ‘small’.
Taxonomy. Bambusoideae; Bambusodae; Bambuseae.
Distribution, ecology, phytogeography. About 120 species; tropical and subtropical Asia, Africa, America. Commonly adventive.
Holarctic, Paleotropical, Neotropical, and Australian. Boreal. Indomalesian. Eastern Asian. Indian, Indo-Chinese, Malesian, and Papuan. Caribbean, Amazon, Central Brazilian, Pampas, and Andean. North and East Australian. Tropical North and East Australian.
Hybrids. Claimed intergeneric hybrids with Saccharum are erroneous, representing apomixis.
Rusts and smuts. Rusts — Dasturella, Stereostratum, and Puccinia. Taxonomically wide-ranging species: Dasturella divina and Stereostratum corticoides. Smuts from Tilletiaceae. Tilletiaceae — Tilletia.
Economic importance. B. arundinacea, B. dissemulator, B. duriuscula, B. gibba, B. lapidea, B. malingensis, B. sinospinosa, B. tuldoides, B. vulgaris etc. are widely used for general constructional work; others (e.g. B. pervariabilis) for fishing rods, ski poles, umbrella shafts, furniture etc.; others (e.g. B. chungii) for weaving; others (e.g. B. flexuosa, B. gibba, B. sinospinosa) are useful barrier plants; and the shoots of many (e.g. B. beecheyana, B. gibboides, B. vulgaris) are edible. Pulp for paper and rayon is obtained from (e.g.) B. guadua.
References, etc. Leaf anatomical: Metcalfe 1960; this project.
Special comments. This treatment follows Clayton and Renvoize (1986). Soderstrom and Ellis (1987) refer Criciuma, Eremocaulon and Guadua to their subtribe Guaduinae, along with Olmeca, and place Tetragonocalamus in the Arundinariinae, but revised generic descriptions adequate for the present purpose are not available. Further problematic ‘genera’ are Kinabaluchloa K.M. Wong (including B. wrayi), Holttumochloa K.M. Wong (including B. magica), Maclurochloa K.M. Wong (= B. pauciflora and B. montana), and Soejatmia K.M. Wong (= B. ridleyi). Sound generic circumscriptions depend on adequate comparative descriptions, and will be extensively unachievable for bamboos until the descriptive terminology of inflorescence and spikelet morphology has been standardized.
Illustrations. • Pseudospikelets. Bambusa arnhemica. • Abaxial epidermis of leaf blade
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).
