Hylebates Chippindall
Habit, vegetative morphology. Annual, or perennial; decumbent. Culms 40–300 cm high; herbaceous. Leaves not basally aggregated. Leaf blades linear to lanceolate; broad; 10–40 mm wide; cordate (amplexicaul, in H. cordatus), or not cordate, not sagittate; not pseudopetiolate; ligule present; a fringed membrane; very short.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence paniculate; open; with capillary branchlets; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund.
Female-fertile spikelets. Spikelets 2–3.5 mm long; compressed dorsiventrally; falling with the glumes; with a distinctly elongated rachilla internode between the glumes. Rachilla terminated by a female-fertile floret. Hairy callus absent.
Glumes two; very unequal (G1 about a third the length of G2); (the upper) about equalling the spikelets; (the upper) long relative to the adjacent lemmas; hairless; awnless; non-carinate; very dissimilar (G1 much smaller, ovate, basally clasping the spikelet). Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; sterile. The proximal lemmas shortly awned (terminally); less firm than the female-fertile lemmas to similar in texture to the female-fertile lemmas (membranous); not becoming indurated.
Female-fertile florets 1. Lemmas similar in texture to the glumes to decidedly firmer than the glumes (thinly papery); smooth (? - dull); not becoming indurated; entire; pointed, or blunt; awnless; hairless; non-carinate; having the margins lying flat on the palea (enfolding and concealing it). Palea present; tightly clasped by the lemma; awnless, without apical setae; 2-nerved. Lodicules present; 2; fleshy. Stamens 3. Stigmas 2.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells markedly different in shape costally and intercostally (the costals narrow, rectangular); of similar wall thickness costally and intercostally (very thin walled). Intercostal zones without typical long-cells (the cells more or less irregularly isodiametric). Mid-intercostal long-cells having markedly sinuous walls and having straight or only gently undulating walls (often very coarsely and irregularly sinuate). Microhairs present; elongated; clearly two-celled; panicoid-type (but unusual, with a vase-shaped basal cell which narrows abruptly towards the apical cell). Stomata common. Subsidiaries non-papillate; low dome-shaped to triangular. Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells absent or very rare. Large, cushion-based macrohairscommon intercostally. Costal short-cells conspicuously in long rows. Costal silica bodies present and well developed; ‘panicoid-type’; dumb-bell shaped and nodular.
Transverse section of leaf blade, physiology. C3. Midrib conspicuous; with one bundle only, or having a conventional arc of bundles (depending on the interpretation of its limits, which might take in a small lateral on eiter side); with colourless mesophyll adaxially. The lamina symmetrical on either side of the midrib. Bulliforms present in discrete, regular adaxial groups; in simple fans. Sclerenchyma all associated with vascular bundles.
Phytochemistry. Leaves without flavonoid sulphates (H. chlorochloë).
Taxonomy. Panicoideae; Panicodae; Paniceae.
Distribution, ecology, phytogeography. 2 species; central Africa. Mesophytic; shade species. In woodland and riverine forest.
Paleotropical. African. Sudano-Angolan. Somalo-Ethiopian and South Tropical African.
Economic importance. Important native pasture species: H. chlorochloë.
References, etc. Leaf anatomical: this project.
Special comments. Fruit data wanting.
Cite this publication as: Watson, L., and Dallwitz, M. J. (1992 onwards). ‘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.’ http://biodiversity.uno.edu/delta/. Version: 18th August 1999. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993 onwards, 1998), and Watson and Dallwitz (1994), and Watson, Dallwitz, and Johnston (1986) should also be cited (see References).