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The grass genera of the world

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

Graphephorum Desv.

~ Trisetum

Habit, vegetative morphology. Perennial; caespitose. Culms 50–100 cm high; herbaceous; unbranched above. Young shoots intravaginal. Leaves non-auriculate; without auricular setae. Leaf blades linear; narrow; 2–8 mm wide; flat; not pseudopetiolate; without cross venation. Ligule an unfringed membrane (?).

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

Inflorescence. Inflorescence paniculate; open to contracted (8–20 cm long, nodding or erect); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate; imbricate.

Female-fertile spikelets. Spikelets 5–7 mm long; compressed laterally; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; copiously hairy (pilose). Hairy callus present. Callus hairs present, more than 0.5 mm long (0.5–2 mm long). Callus short.

Glumes two; very unequal to more or less equal; (the upper) about equalling the spikelets; long relative to the adjacent lemmas (about as long); hairless; scabrous; pointed; awnless; carinate; similar. Spikelets with female-fertile florets only, or with incomplete florets (?). The incomplete florets (if they occur) distal to the female-fertile florets. The distal incomplete florets merely underdeveloped.

Female-fertile florets 2–3(–4) (‘two to several’). Lemmas not becoming indurated; entire; pointed to blunt; awnless (usually), or mucronate (rarely with a dorsal, subapical awn-point); hairless (above the callus); scabrous; carinate; without a germination flap; 5 nerved (or more?); with the nerves non-confluent. Palea present; relatively long; tightly clasped by the lemma; awnless, without apical setae; 2-nerved; 2-keeled. Ovary apically glabrous.

Fruit, embryo and seedling. Fruit not grooved; smooth. Hilum short (?). Pericarp thin. Embryo small (?).

Special diagnostic feature. Female-fertile lemma not as in Lombardochloa (q.v.).

Classification. Watson & Dallwitz (1994): Pooideae; Triticodae; Aveneae. Soreng et al. (2015): Pooideae; Poodae; Poeae; Aveninae. 3 species (Clayton and Renvoize 1986).

Distribution, phytogeography, ecology. North and central America.

Caribbean.

Helophytic, or mesophytic; species of open habitats; glycophytic. Boggy meadows and moist ground, or montane.

References, etc. Morphological/taxonomic: Hitchcock and Chase (1950: Trisetum melicoides, T.wolfii); Clayton and Renvoize (1986).

Special comments. Description very inadequate. Fruit data wanting. Anatomical data wanting. Illustrations. • G. melicoides (as melicoideum): P. Beauv. (1812). • G. melicoides (as Trisetum): Hitchcock and Chase (1950). • G. wolfii (as Trisetum): Hitchcock and Chase (1950)


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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: 13th November 2017. delta-intkey.com/grass’.

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