The grass genera of the world
~ Briza, Chascolytrum
Including Poidium rufum (Presl) Mattei
Habit, vegetative morphology. Perennial; caespitose. Culms 50–150 cm high (?); herbaceous. Young shoots intravaginal. Leaves non-auriculate. The fibrous remains of the sheaths persisting. Leaf blades narrow; flat, or folded; without cross venation; persistent. Ligule an unfringed membrane.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets; exposed-cleistogamous, or chasmogamous (?).
Inflorescence. Inflorescence paniculate; open; espatheate; not comprising partial inflorescences and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets compressed laterally; disarticulating above the glumes; disarticulating between the florets; with a distinctly elongated rachilla internode above the glumes. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets. Hairy callus present. Callus short.
Glumes two; more or less equal; about equalling the spikelets; long relative to the adjacent lemmas; hairless; glabrous; awnless; carinate; similar (naviculate). Lower glume 3 nerved. Upper glume 3 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped.
Female-fertile florets 2–4. Lemmas broad, with a succulent, translucent region near the base of each wing; not becoming indurated; entire; pointed to blunt; awnless; hairless; carinate to non-carinate (slightly keeled when mature); 5 nerved. Palea present; relatively long; entire (acute or obtuse); awnless, without apical setae; not indurated; 2-nerved; 2-keeled. Palea keels wingless. Lodicules present; 2; free; membranous; glabrous; not toothed. Stamens 3, or 1 (in cleistogamous florets). Ovary apically glabrous. Stigmas 2.
Fruit, embryo and seedling. Fruit adhering to lemma and/or palea to free from both lemma and palea; longitudinally grooved. Hilum short. Endosperm with lipid.
Phytochemistry. Leaves without flavonoid sulphates (1 species).
Special diagnostic feature. Lemmas not as in Briza (q.v.). Female-fertile lemma very broad, with a conspicuous, succulent, translucent region near the base of each wing.
Classification. Watson & Dallwitz (1994): Pooideae; Poodae; Poeae. Soreng et al. (2015): Pooideae; Poodae; Poeae; Calothecinae. 1 species.
Distribution, phytogeography, ecology. South America.
References, etc. Morphological/taxonomic: Rosengurtt and Arrillaga de Maffei 1979.
Special comments. Anatomical data wanting.
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: 13th November 2017. delta-intkey.com/grass’.