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The grass genera of the world

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

Cambajuva Viana, Clark & Filg.

~ Arundinaria, Aulonemia

Type species: C. ulei (Hack.) Vianna, Clark & Filg.

Habit, vegetative morphology. Perennial; rhizomatous and caespitose. Culms erect, woody and persistent; not mottled, cylindrical; branched above to unbranched above. Buds from which the primary culm branches arise 1. Primary branches borne on promontories, 1–7; clumped. The branching apparently mostly simple (the branches each bearing 4–14 leaves). Culm nodes smooth or striate. Culm leaves present (clearly different from the foliage leaves). Culm leaf sheaths present; tardily deciduous; not conspicuously auriculate (but with auricular setae). Culm leaves with conspicuous blades. Culm leaf blades not pseudopetiolate, lanceolate to ovate, or triangular. Culm internodes hollow. Rhizomes pachymorph. Leaves auriculate; with auricular setae. Leaf blades lanceolate; leathery; broad to narrow; 2.7–8.7 cm long, 4–9 mm wide; pseudopetiolate; erect, cross veined. Ligule a fringed membrane; about 0.4 mm long. Contra-ligule present.

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

Inflorescence. Inflorescence determinate; a single spike to of spicate main branches, or paniculate (comprising spiciform branches appressed to the main axis); espatheate (the peduncle usually within a foliage leaf sheath); not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes ‘racemes’. Spikelets pedicellate (the pedicels 1.4–5.4 mm long).

Female-fertile spikelets. Spikelets morphologically ‘conventional’; 12–22 mm long; 2–3 mm wide, elliptic, or linear; slightly compressed laterally; disarticulating above the glumes; disarticulating between the florets; with conventional internode spacings. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets.

Glumes two; very unequal; shorter than the spikelets; shorter than the adjacent lemmas; ciliate above, hairy to hairless (glabrous to puberulous); pointed; awned (both acuminate into the awn); non-carinate; similar. Lower glume about 0.7 times the length of the upper glume; 6–9 nerved. Upper glume 7–9 nerved. Spikelets with incomplete florets. The incomplete florets both distal and proximal to the female-fertile florets. The distal incomplete florets 1; merely underdeveloped; awned. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; paleate. Palea of the proximal incomplete florets reduced. The proximal incomplete florets sterile. The proximal lemmas glumiform; awned; about 11 nerved; exceeded by the female-fertile lemmas; similar in texture to the female-fertile lemmas.

Female-fertile florets 2–4. Lemmas similar in texture to the glumes; white in fruit; entire; awned. Awns 1; median; apical; non-geniculate; straight (i.e., the lemma acuminate into the awn); hairless; much shorter than the body of the lemma; entered by one vein. Lemmas puberulous, hairless; 9–12 nerved; with the nerves non-confluent. Palea present; relatively long; not convolute; entire (apically acute to rounded,); awnless, without apical setae; several nerved (10 nerved); 2-keeled. Lodicules present; 3; free; membranous; ciliate; obovate to broadly elliptic, not toothed; heavily vascularized. Stamens 3. Anthers 6.2–8 mm long; not penicillate; without an apically prolonged connective. Ovary apically hairy; without a conspicuous apical appendage. Stigmas 2.

Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present (abundant); costal and intercostal. Intercostal papillae over-arching the stomata; consisting of one oblique swelling per cell, or several per cell. Microhairs absent. Stomata common. Without trichomes abaxially.

Transverse section of leaf blade, physiology. Lamina mid-zone in transverse section open.

C3; XyMS+. Mesophyll with non-radiate chlorenchyma; without adaxial palisade; without ‘circular cells’; not traversed by colourless columns; with arm cells; without fusoids. Leaf blade ‘nodular’ in section to adaxially flat. Midrib conspicuous; with one bundle only, or having complex vascularization (?); without colourless mesophyll adaxially. The lamina symmetrical 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’. Sclerenchyma all associated with vascular bundles (except in the blade margins). The lamina margins with fibres.

Classification. Watson & Dallwitz (1994): not described separately. Soreng et al. (2015): Bambusoideae; Bambusodae; Bambuseae; Arthrostylidiinae. 1 species (C. ulei).

Distribution, phytogeography, ecology. Southern Brazil.

Helophytic. In peaty bogs, less often in riparian vegetation.

References, etc. Morphological/taxonomic: Viana et al. (2013), Syst. Bot. 38. Leaf anatomical: Viana et al.

Special comments. Fruit data wanting.

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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.’.