Lycochloa Samuelsson
Habit, vegetative morphology. Perennial; rhizomatous. Culms herbaceous. Leaves non-auriculate. Sheath margins free. Leaf blades without cross venation; an unfringed membrane; truncate; 4–5 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets all alike in sexuality.
Inflorescence. Inflorescence a single raceme (lax); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets solitary; secund (nodding to one side); shortly pedicellate; not imbricate.
Female-fertile spikelets. Spikelets 15–20 mm long; compressed laterally; disarticulating above the glumes; not disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets. Hairy callus present. Callus blunt.
Glumes two; very unequal; shorter than the adjacent lemmas; pointed (acute); awnless; similar (papery). Lower glume 5 nerved. Upper glume 5 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets 3–4; clearly specialised and modified in form (forming a narrowly lanceolate cluster). Spikelets without proximal incomplete florets.
Female-fertile florets 2. Lemmas decidedly firmer than the glumes (leathery); not becoming indurated; incised; 2 lobed; not deeply cleft (bidentate); awned. Awns 1; median; dorsal; from near the top (or at about 1/3 the way down); geniculate. Lemmas hairy; non-carinate; without a germination flap; 7–11 nerved (and ribbed). Palea present; 2-nerved. Lodicules present; 2; joined; fleshy; not toothed; not or scarcely vascularized. Ovary glabrous (?); without a conspicuous apical appendage (?). Stigmas 2 (?).
Fruit, embryo and seedling. Fruit free from both lemma and palea; medium sized (5–8 mm long). Hilum long-linear. Embryo small. Endosperm hard; without lipid.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Intercostal zones exhibiting many atypical long-cells (some tending to be hexagonal). Mid-intercostal long-cells having markedly sinuous walls. Microhairs absent. Stomata absent or very rare. Intercostal short-cells common; not paired; silicified. Intercostal silica bodies tall-and-narrow (elliptical). Costal short-cells conspicuously in long rows, or neither distinctly grouped into long rows nor predominantly paired (mostly in short or long rows, some solitary). Costal silica bodies ‘panicoid-type’; mostly nodular; not sharp-pointed.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma. Leaf blade with distinct, prominent adaxial ribs to adaxially flat (the abaxial ribs more conspicuous); with the ribs more or less constant in size. Midrib conspicuous; with one bundle only. Bulliforms present in discrete, regular adaxial groups; in simple fans and associated with colourless mesophyll cells to form deeply-penetrating fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’. Sclerenchyma all associated with vascular bundles.
Special diagnostic feature. Plant and inflorescence not as in Lygeum (q.v.).
Taxonomy. Pooideae; Poodae; Meliceae.
Distribution, ecology, phytogeography. 1 species; Lebanon. Xerophytic (among rocks).
Holarctic. Tethyan. Irano-Turanian.
References, etc. Leaf anatomical: Metcalfe 1960.
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).