Ammochloa Boiss.
From the Greek ammos (sand) and chloë (grass), re habitat.
Including Cephalochloa Coss. & Dur., Dictyochloa (Murbeck) E.G. Camus
Habit, vegetative morphology. Annual; caespitose. Culms 1–25 cm high; herbaceous; unbranched above. Culm internodes hollow. Leaves mostly basal; non-auriculate. Leaf blades linear to linear-lanceolate; narrow; 1–3 mm wide; flat, or rolled (convolute); without cross venation; persistent; an unfringed membrane; not truncate; 0.5–5 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets of sexually distinct forms on the same plant; hermaphrodite and sterile (the latter reduced to small, sterile bracts at the base of the inflorescence); overtly heteromorphic.
Inflorescence. Inflorescence paniculate; contracted; capitate to more or less ovoid (reduced to a sub-globose head of close-packed spikelets); espatheate. Spikelet-bearing axes persistent. Spikelets associated with bractiform involucres (these representing basal, sterile spikelets); not secund; subsessile.
Female-fertile spikelets. Spikelets 4–9 mm long; compressed laterally; disarticulating above the glumes. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension naked. Hairy callus absent. Callus short.
Glumes two (ovate-oblique); more or less equal; shorter than the spikelets; long relative to the adjacent lemmas; pointed; awnless; carinate (sometimes narrowly winged); similar (papery to membranous). Lower glume 1–2 nerved. Upper glume 1–2 nerved. Spikelets with female-fertile florets only.
Female-fertile florets 4–12. Lemmas similar in texture to the glumes to decidedly firmer than the glumes (papery to membranous, becoming leathery); not becoming indurated; entire; pointed; mucronate (the mucro recurved); hairless; carinate; 5–7 nerved. Palea present; relatively long; entire to apically notched; awnless, without apical setae; not indurated (membranous); 2-nerved; 2-keeled. Lodicules absent. Stamens 2–3. Anthers 0.6–0.8 mm long; not penicillate. Ovary glabrous; with a conspicuous apical appendage (this membranous, associated with the style). Styles fused. Stigmas 2.
Fruit, embryo and seedling. Fruit free from both lemma and palea; small to large (winged via the ovary appendage); compressed laterally, or not noticeably compressed. Hilum short. Embryo large, or small. Endosperm hard; with lipid. Embryo with an epiblast; without a scutellar tail; with a negligible mesocotyl internode. Embryonic leaf margins meeting.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells markedly different in shape costally and intercostally; of similar wall thickness costally and intercostally. Mid-intercostal long-cells fusiform; having straight or only gently undulating walls. Microhairs absent. Stomata common. Subsidiaries parallel-sided. Guard-cells overlapped by the interstomatals. Intercostal short-cells absent or very rare. Costal short-cells neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies horizontally-elongated crenate/sinuous.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; without adaxial palisade. Leaf blade adaxially flat. Midrib conspicuous (rounded keel with larger bundle); with one bundle only. Bulliforms not present in discrete, regular adaxial groups; nowhere involved in bulliform-plus-colourless mesophyll arches. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders absent (strands only). Sclerenchyma all associated with vascular bundles.
Cytology. Chromosomes ‘large’.
Taxonomy. Pooideae; Poodae; Aveneae.
Distribution, ecology, phytogeography. 3 species; Mediterranean. Xerophytic; species of open habitats. Dry sandy places.
Holarctic and Paleotropical. Boreal and Tethyan. African. Euro-Siberian. Macaronesian, Mediterranean, and Irano-Turanian. Saharo-Sindian. European.
Rusts and smuts. Smuts from Tilletiaceae. Tilletiaceae — Tilletia.
References, etc. Leaf anatomical: 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).