| # The grass genera of the world |

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

### Cyrtochloa J. Dransfield

~ Schizostachyum

Habit, vegetative morphology. Perennial; shortly rhizomatous. Culms 100–1040 cm high; woody and persistent; cylindrical; scandent, or not scandent; self-supporting, or decumbent, or scrambling (or geniculately ascending); branched above. Primary branches 4–20. The branching dendroid (with one branch dominant). Culm leaf sheaths present; where recorded, persistent; conspicuously auriculate. Culm leaves with conspicuous blades. Culm leaf blades ovate, or triangular. Rhizomes pachymorph. Leaves auriculate (falcate), or non-auriculate; without auricular setae. Leaf blades lanceolate; herbaceous to leathery, leathery, or neither leathery nor flimsy; pseudopetiolate. Ligule an unfringed membrane, or a fringed membrane. Contra-ligule absent.

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

Inflorescence. Inflorescence indeterminate; with pseudospikelets; a false spike, with spikelets on contracted axes, or paniculate (with alternate clusters of pseudospikelets in spike-like or paniculate inflorescences, which are leafless or leafy below); spatheate; a complex of ‘partial inflorescences’ and intervening foliar organs (with glumaceous or spathaceous subtending bracts and basal axillary buds). Spikelet-bearing axes spikelike, or paniculate; persistent. Spikelets sessile.

Female-fertile spikelets. Spikelets unconventional; 4–12 mm long; elliptic, or lanceolate, or ovate, or linear; compressed laterally; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret, or terminated by a female-fertile floret; the rachilla extension with incomplete florets, or naked.

Glumes persistent, two to several; shorter than the spikelets; hairy, or hairless (glabrous to pubescent); pointed (acute or acuminate); muticous or mucronate, awnless; non-carinate; ovate, chartaceous, similar. Lower glume relatively smooth; 5 nerved, or 6 nerved, or 7 nerved. Upper glume 5 nerved, or 6 nerved, or 7 nerved, or 9 nerved. Spikelets with female-fertile florets only, or with incomplete florets. The incomplete florets when present, distal to the female-fertile florets. The distal incomplete florets 1; merely underdeveloped; awnless. Spikelets without proximal incomplete florets.

Female-fertile florets 1. Lemmas ovate; chartaceous, similar in texture to the glumes; smooth; not becoming indurated; white in fruit; entire; pointed (acute, acuminate, attenuate or setaceously so); awnless, or mucronate, or awned. Awns if present, 1; median; apical; non-geniculate. Lemmas hairy, or hairless (glabrous or pubescent); non-carinate; 5–9 nerved. Palea present; relatively long; convolute around the flower; awned; chartaceous, textured like the lemma; not indurated; several nerved (4–6); keel-less. Palea back glabrous, or scabrous, or hairy. Lodicules present; 2, or 3; ciliate. Stamens 6. Ovary with a conspicuous apical appendage. The appendage long, stiff and tapering. Stigmas 3.

Fruit, embryo and seedling. Fruit oblong, orbicular or ovoid. Pericarp thin, or thick and hard, or fleshy; free.

Classification. Watson & Dallwitz (1994): genus not recognised. Soreng et al. (2015): Bambusoideae; Bambusodae; Bambuseae; Bambusinae. 7 species.

Distribution, phytogeography, ecology. Malesia.

References, etc. Morphological/taxonomic: Dransfield, S. (1998). Cyrtochloa, a New Genus of Bamboo (Gramineae-Bambusoideae) from the Philippines. Kew Bull. 53, 857–873; Clayton et al. (2016), Grassbase.

Special comments. Anatomical data wanting.

Illustrations. • Cyrtochloa fenixii, as Schizostachyum: herb. specimen, Brown & Fischer, Philippine Bamboos (1918). • Cyrtochloa luzonicum, as Schizostachyum: herb. specimen, Brown & Fischer, Philippine Bamboos (1918). • Cyrtochloa toppingii, as Schizostachyum: herb. specimen, Brown & Fischer, Philippine Bamboos (1918).

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: 15th June 2025. delta-intkey.com’.

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