Aeluropus Trin.
From the Greek ailuros (cat) and pous (foot), the allusion obscure.
Including Aelbroeckia De Moor, Chamaedactylis T. Nees
Habit, vegetative morphology. Perennial; rhizomatous, or stoloniferous, or caespitose, or decumbent. Culms 5–40 cm high; herbaceous; branched above, or unbranched above. Leaves not basally aggregated; non-auriculate. Leaf blades linear to linear-lanceolate (with a cartilaginous, often pungent apex); narrow; 0.6–3 mm wide; flat, or folded; without abaxial multicellular glands; without cross venation; a fringed membrane to a fringe of hairs.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence a single spike (ovoid to capitate), or of spicate main branches (then a 2-sided raceme of short, densely spiculate sessile spikes appressed to the main axis); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets solitary; secund.
Female-fertile spikelets. Spikelets 2.2–5 mm long; compressed laterally; disarticulating above the glumes. Rachilla prolonged beyond the uppermost female-fertile floret; hairless. Hairy callus absent. Callus short; blunt.
Glumes two; very unequal; shorter than the spikelets; shorter than the adjacent lemmas; lateral to the rachis; awnless; carinate; similar (membranous to leathery). Lower glume 1–3 nerved. Upper glume 5–7 nerved. Spikelets without proximal incomplete florets.
Female-fertile florets 4–18. Lemmas similar in texture to the glumes; not becoming indurated; entire, or incised; when incised, not deeply cleft (emarginate); mucronate; hairy; carinate; 9–11 nerved. Palea present; relatively long; entire to apically notched; awnless, without apical setae; not indurated (membranous); 2-nerved. Lodicules present; 2; free; fleshy; ciliate, or glabrous. Stamens 3. Anthers 0.8–1.6 mm long; not penicillate. Ovary glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit free from both lemma and palea; ellipsoid; compressed dorsiventrally. Hilum short. Pericarp fused. Embryo large; not waisted. Endosperm hard; without lipid; containing compound starch grains. Embryo with an epiblast; with a scutellar tail; with an elongated mesocotyl internode. Embryonic leaf margins meeting.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present (very abundant, large, thick walled); costal and intercostal. Intercostal papillae over-arching the stomata (so as to thoroughly obscure them); consisting of one oblique swelling per cell, or consisting of one symmetrical projection per cell. Long-cells markedly different in shape costally and intercostally (the costals conventionally shaped); of similar wall thickness costally and intercostally (quite thick walled). Intercostal zones exhibiting many atypical long-cells (all being relatively short). Mid-intercostal long-cells rectangular (to irregular); having markedly sinuous walls. Microhairs present; more or less spherical, or elongated; clearly two-celled; chloridoid-type. Microhair apical cell wall of similar thickness/rigidity to that of the basal cell. Microhairs 21–27 microns long. Microhair basal cells 9 microns long. Microhairs 13.5–18 microns wide at the septum. Microhair total length/width at septum 1.5–2. Microhair apical cells 14–18 microns long. Microhair apical cell/total length ratio 0.55–0.69. Stomata common (but almost invisible). Subsidiaries non-papillate; triangular. Intercostal short-cells common; hard to observe, but seemingly solitary, paired and even in short rows; not silicified. Intercostal silica bodies absent. Costal short-cells conspicuously in long rows. Costal silica bodies present in alternate cell files of the costal zones; ‘panicoid-type’; mostly short butterfly shaped to dumb-bell shaped (a few almost square).
Transverse section of leaf blade, physiology. Lamina mid-zone in transverse section open.
C4; XyMS+. PCR sheath outlines even. PCR sheaths of the primary vascular bundles complete to interrupted; interrupted abaxially only. PCR sheath extensions absent. PCR cell chloroplasts centripetal. Mesophyll with radiate chlorenchyma; traversed by columns of colourless mesophyll cells (at least in places). Leaf blade with distinct, prominent adaxial ribs; with the ribs more or less constant in size. Midrib not readily distinguishable; with one bundle only. Bulliforms present in discrete, regular adaxial groups; in simple fans, or associated with colourless mesophyll cells to form deeply-penetrating fans (sometimes associated with colourless girders). All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’. Sclerenchyma all associated with vascular bundles. The lamina margins with fibres.
Cytology. Chromosome base number, x = 10. 2n = 20. 2 ploid. Chromosomes ‘small’.
Taxonomy. Chloridoideae; main chloridoid assemblage.
Distribution, ecology, phytogeography. 5 species; Mediterranean to India. Species of open habitats; halophytic. In sand of seashores and deserts.
Holarctic and Paleotropical. Boreal and Tethyan. African. Euro-Siberian. Mediterranean and Irano-Turanian. Saharo-Sindian and Sudano-Angolan. European and Siberian. Sahelo-Sudanian and Somalo-Ethiopian.
Rusts and smuts. Rusts — Puccinia. Smuts from Ustilaginaceae. Ustilaginaceae — Sorosporium and Sphacelotheca.
References, etc. Leaf anatomical: Metcalfe 1960; this project.
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).