Coelachyropsis Bor
Sometimes referred to Coelachyrum
Habit, vegetative morphology. Annual; decumbent. Culms 10–25 cm high; herbaceous; unbranched above. Culm nodes glabrous. Leaves not basally aggregated; non-auriculate. Leaf blades narrow; 2–6 mm wide; exhibiting multicellular glands abaxially. The abaxial leaf blade glands on the blade margins, or costal (elongated, one cell file, with 4–8 cells). Leaf blades without cross venation; persistent; a fringed membrane.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence of spicate main branches (2–3 short spikes, in the material seen); digitate. Primary inflorescence branches 2–3. Inflorescence with axes ending in spikelets. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets solitary; secund; biseriate.
Female-fertile spikelets. Spikelets 5–7 mm long; compressed laterally; disarticulating above the glumes (?), or not disarticulating. Rachilla prolonged beyond the uppermost female-fertile floret; hairless; the rachilla extension with incomplete florets. Hairy callus absent.
Glumes two; more or less equal; shorter than the spikelets; shorter than the adjacent lemmas; lateral to the rachis; hairless; glabrous; pointed; awnless (but mucronate); carinate; similar (membranous-hyaline, broadly lanceolate acuminate). Lower glume 1 nerved. Upper glume 3–4 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 5–8. Lemmas broadly ovate, acuminate; not saccate; similar in texture to the glumes (membranous); not becoming indurated; entire; pointed; mucronate (attenuate into the mucro); hairy (with long white hairs on the lower half along the nerves); carinate; having the margins lying flat on the palea; without a germination flap; 3 nerved. Palea present; relatively long; entire; awnless, without apical setae; not indurated (membranous); 2-nerved (with hairs along their lower two thirds); 2-keeled. Lodicules present; 2; free; fleshy; not or scarcely vascularized. Stamens 3 (with tiny anthers). Anthers not penicillate; without an apically prolonged connective. Ovary glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit free from both lemma and palea; small (about 1 mm long); compressed dorsiventrally (angular when dry, and concave on the side away from the embryo); sculptured (cf. Acrachne). Hilum short. Pericarp free. Embryo large. Endosperm hard.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present; intercostal. Intercostal papillae over-arching the stomata, or not over-arching the stomata; consisting of one oblique swelling per cell (large). Long-cells markedly different in shape costally and intercostally (the costals conventional, with sinuous walls). Intercostal zones with typical long-cells (long-cells thin walled, deforming, some may be short). Mid-intercostal long-cells having straight or only gently undulating walls. Microhairs present; more or less spherical; clearly two-celled; chloridoid-type. Microhair apical cell wall of similar thickness/rigidity to that of the basal cell. Microhair basal cells 9–12 microns long. Microhair total length/width at septum about 2. Microhair apical cell/total length ratio about 0.5. Stomata common. Subsidiaries non-papillate; including both triangular and parallel-sided forms on the same leaf. Guard-cells overlapping to flush with the interstomatals (except for overlapping by papillae). Intercostal short-cells absent or very rare. Costal short-cells conspicuously in long rows (although the short-cells are often rather long). Costal silica bodies present in alternate cell files of the costal zones; ‘panicoid-type’; cross shaped and nodular (with points); sharp-pointed (the crosses and dumb-bells with points).
Transverse section of leaf blade, physiology. Lamina mid-zone in transverse section open.
C4; XyMS+. PCR sheaths of the primary vascular bundles interrupted; interrupted both abaxially and adaxially. PCR sheath extensions absent. Leaf blade probably adaxially flat. Midrib not readily distinguishable; with one bundle only; with colourless mesophyll adaxially (there being colourless tissue adaxial to all the large vascular bundles). 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 absent (colourless, large-celled bundle sheath extensions adaxially). Sclerenchyma all associated with vascular bundles. The lamina margins with fibres.
Taxonomy. Chloridoideae; main chloridoid assemblage.
Distribution, ecology, phytogeography. 1 species; southern India, Ceylon.
Paleotropical. Indomalesian. Indian.
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).