Bewsia Goossens
Habit, vegetative morphology. Perennial; caespitose (with short, creeping rhizomes). Culms 26–93 cm high; herbaceous; to 0.2 cm in diameter; unbranched above. Culm nodes glabrous. Culm internodes solid. Plants unarmed. Young shoots intravaginal. Leaves mostly basal; non-auriculate; without auricular setae (but hairy at the mouth of the sheath and on the lower part of the blade). Leaf blades linear to linear-lanceolate; narrow; to 5 mm wide; flat, or rolled (the margins becoming involute under water stress); without abaxial multicellular glands; without cross venation; an unfringed membrane (minutely ciliolate only); truncate; to 0.3 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality.
Inflorescence. Inflorescence of spicate main branches (these appressed to the central axis). Primary inflorescence branches about 10–15. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes ‘racemes’. The racemes spikelet bearing to the base. Spikelet-bearing axes persistent. Spikelets solitary; somewhat secund; biseriate; shortly pedicellate; imbricate.
Female-fertile spikelets. Spikelets 5.5–9 mm long; adaxial; strongly compressed laterally; disarticulating above the glumes; not disarticulating between the florets; with conventional internode spacings (rather long). Rachilla prolonged beyond the uppermost female-fertile floret; hairy (between L1 and L2); the rachilla extension with incomplete florets. Hairy callus present. Callus short; blunt.
Glumes two; more or less equal; about equalling the spikelets (a little shorter to a little longer); long relative to the adjacent lemmas; dorsiventral to the rachis; hairless (scabridulous); pointed (acuminate, often mucronate); awnless; strongly carinate; similar. Lower glume 1 nerved. Upper glume 1 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped. Spikelets without proximal incomplete florets.
Female-fertile florets 2–6. Lemmas similar in texture to the glumes (membranous); not becoming indurated; entire, or incised; not deeply cleft (no more than minutely notched); awned. Awns 1; median; dorsal; from a quarter to a third of the way down; non-geniculate; hairless (scabrid); much shorter than the body of the lemma to about as long as the body of the lemma (1–4 mm long); entered by one vein. Lemmas hairy (the lower lemmas hairy below, beside the keel and on the margins); carinate; without a germination flap; 3 nerved; with the nerves non-confluent. Palea present; relatively long; minutely apically notched; awnless, without apical setae; textured like the lemma; not indurated; 2-nerved; 2-keeled. Palea keels hairy (minutely, densely ciliate). Lodicules present; 2; free; fleshy (long, narrow); glabrous. Stamens 3. Anthers 1.5–2.5 mm long; not penicillate; without an apically prolonged connective. Ovary glabrous. Styles free to their bases. Stigmas 2; red pigmented.
Fruit, embryo and seedling. Fruit small (about 2 mm long); linear (to oblong); not noticeably compressed (terete). Pericarp fused.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells of similar wall thickness costally and intercostally (fairly thick walled). Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs absent. Stomata common (in rather distant single files). Subsidiaries parallel-sided to triangular (rather irregular - mostly high domes with truncated tops). Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells common; not paired (solitary); not silicified (in material seen). Intercostal silica bodies absent. Prickles abundant. Costal short-cells conspicuously in long rows (the files interrupted by prickles). Costal silica bodies present and well developed (usually?), or absent (in some material seen, but the silica cells nodular); present in alternate cell files of the costal zones; ‘panicoid-type’; dumb-bell shaped (with long, inconspicuous isthmuses), or nodular (a few).
Transverse section of leaf blade, physiology. Lamina mid-zone in transverse section open.
C4; XyMS+ (the MS thick-walled, sometimes double). PCR sheath outlines even. PCR sheaths of the primary vascular bundles interrupted; interrupted both abaxially and adaxially. PCR sheath extensions absent. PCR cell chloroplasts centripetal. Leaf blade adaxially flat (or with very low flat-topped ribs). Midrib conspicuous to not readily distinguishable; with one bundle only. Bulliforms present in discrete, regular adaxial groups; associated with colourless mesophyll cells to form deeply-penetrating fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with all the bundles); forming ‘figures’ (all bundles with anchors). Sclerenchyma all associated with vascular bundles to not all bundle-associated. The ‘extra’ sclerenchyma when present, in a continuous abaxial layer. The lamina margins with fibres.
Cytology. 2n = 30.
Taxonomy. Chloridoideae; main chloridoid assemblage.
Distribution, ecology, phytogeography. 1 species; southern tropical and South Africa. Mesophytic; species of open habitats. In grassveld, often on sandy soil.
Paleotropical. African. Sudano-Angolan. Sahelo-Sudanian and South Tropical African.
Rusts and smuts. Rusts — Puccinia.
References, etc. Leaf anatomical: this project; photos provided by R.P. Ellis.
Illustrations. • General aspect
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).
