| # The grass genera of the world |

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

### Cyathopus Stapf

Referring to cupular pedicel tips.

Habit, vegetative morphology. Perennial. Culms 90–140 cm high; herbaceous. Leaves non-auriculate. Leaf blades narrow; flat; not pseudopetiolate; without cross venation. Ligule an unfringed membrane; not truncate.

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

Inflorescence. Inflorescence paniculate (many spikeleted); open (large); with capillary branchlets; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets solitary; pedicellate. Pedicel apices minutely cupuliform.

Female-fertile spikelets. Spikelets about 3 mm long; compressed laterally to not noticeably compressed; falling with the glumes. Rachilla terminated by a female-fertile floret.

Glumes present; two; more or less equal; long relative to the adjacent lemmas (slightly exceeding them); hairy; without conspicuous tufts or rows of hairs; pointed; awnless (but caudate); non-carinate (dorsally rounded); similar (chartaceous, each with a small apical beak). Lower glume strongly 3 nerved. Upper glume strongly 3 nerved. Spikelets with female-fertile florets only; without proximal incomplete florets.

Female-fertile florets 1. Lemmas ovate; less firm than the glumes (scarious); not becoming indurated; entire; pointed to blunt; awnless (muticous); hairless; carinate (weakly), or non-carinate (dorsally rounded); 5 nerved (the nerves obscure towards the apex). Palea present; relatively long; entire (pointed); awnless, without apical setae; not indurated (hyaline); 2-nerved; 2-keeled. Palea keels wingless. Lodicules present; 2; free; apparently not cuneate; glabrous; not toothed. Stamens 3. Anthers not penicillate; without an apically prolonged connective. Ovary apically glabrous. Stigmas 2.

Fruit, embryo and seedling. Fruit small (about 2 mm long). Hilum short. Embryo large.

Classification. Watson & Dallwitz (1994): Pooideae (? - not reliably classifiable without better data); Poodae (?); Aveneae (?). Soreng et al. (2015): Pooideae; Poodae; Poeae; Poinae. 1 species (C. sikkimensis).

Distribution, phytogeography, ecology. Eastern Himalayas.

Mesophytic; shade species; glycophytic. In woods.

References, etc. Morphological/taxonomic: Stapf 1895.

Special comments. Fruit data wanting. Anatomical data wanting.

Illustrations. • Cyathopus sikkaminensis: Hook. Ic. Pl. 24 (1895).

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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