The grass genera of the world
The grass genera of the world |
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From the Greek pitein (to fall) and phullon (leaf), alluding to disarticulating leaf blades.
Including ‘Pentaschistis welwitschii’
Sometimes referred to cf. Triraphis, Crinipes
Habit, vegetative morphology. Slender, erect perennial; caespitose (the base tomentose and fibrous). Culms herbaceous; unbranched above. Leaves non-auriculate. Leaf blades narrow; setaceous (folded); without cross venation; disarticulating from the sheaths. Ligule present; a fringe of hairs.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence determinate; without pseudospikelets; paniculate; open (lanceolate-oblong or narrowly oblong); with capillary branchlets; non-digitate; 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 conventional internode spacings (the internodes very short). Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension naked.
Glumes two; relatively large; more or less equal (only slightly unequal); shorter than the spikelets; shorter than the adjacent lemmas; acute or the apex minutely toothed; awnless (but mucronate); similar (thinly membranous). Lower glume 1 nerved. Upper glume 1 nerved. Spikelets with female-fertile florets only; without proximal incomplete florets.
Female-fertile florets 2. Lemmas not becoming indurated (herbaceous membranous, becoming firm); incised; 2 lobed; not deeply cleft (the lobes narrow, terminating in short setae); awned. Awns 1; median; from a sinus; non-geniculate to geniculate (very slender, curved or flexuose above but flattened and twisted at the base). Lemmas hairy (pilose on the margins); non-carinate (convex); 5–9 nerved. Palea present; relatively long; entire (obtuse), or apically notched; awnless, without apical setae; not indurated (thinly membranous); 2-nerved; 2-keeled. Lodicules present; 2; fleshy (minute); minutely ciliate, or glabrous. Stamens 3. Ovary glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit not noticeably compressed (terete). Hilum short (but linear). Embryo large.
Transverse section of leaf blade, physiology. Lamina mid-zone in transverse section open.
Taxonomy. Arundinoideae, or Chloridoideae (?); if arundinoid, Danthonieae (?); if chloridoid, main chloridoid assemblage (?).
Distribution, ecology, phytogeography. 1 species; Angola. Mesophytic; species of open habitats. Damp rocky places.
Paleotropical. African. Sudano-Angolan. South Tropical African.
References, etc. Morphological/taxonomic: Hubbard 1957.
Special comments. Taxonomic relationships impossible to determine reliably with neither leaf anatomical nor photosynthetic pathway data. Anatomical data wanting.
This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using 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 specified attributes, summaries of attributes within groups of taxa, geographical distribution, classification, and species sampled for anatomy.
Cite this publication as: ‘Watson, L., 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 February 2012. http://delta-intkey.com’.