Cyrtococcum Stapf
From the Greek kurtos (curved, crooked) and kokkos (a fruit), alluding to the gibbous spikelets.
Habit, vegetative morphology. Annual, or perennial; stoloniferous, or decumbent. Culms 15–100 cm high; herbaceous. Culm nodes glabrous. Culm internodes hollow. Leaves not basally aggregated; non-auriculate. Leaf blades linear-lanceolate to ovate; broad, or narrow; cordate, or not cordate, not sagittate; pseudopetiolate, or not pseudopetiolate; cross veined, or without cross venation; persistent; rolled in bud; an unfringed membrane to a fringed membrane.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence paniculate; open, or contracted. Primary inflorescence branches inserted all around the main axis. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate. Pedicel apices cupuliform.
Female-fertile spikelets. Spikelets 1–2.5 mm long; oblong, or elliptic, or obovate; gibbous, compressed laterally; falling with the glumes. Rachilla terminated by a female-fertile floret. Hairy callus absent.
Glumes two; more or less equal; shorter than the spikelets; shorter than the adjacent lemmas; awnless; carinate; similar (membranous, the upper blunt). Lower glume 1–3 nerved. Upper glume 3 nerved. Spikelets with incomplete florets. The incomplete florets proximal to the female-fertile florets. Spikelets with proximal incomplete florets. The proximal incomplete florets 1; paleate, or epaleate. Palea of the proximal incomplete florets when present, reduced. The proximal incomplete florets sterile. The proximal lemmas blunt; awnless; 3–5 nerved; more or less equalling the female-fertile lemmas; less firm than the female-fertile lemmas to decidedly firmer than the female-fertile lemmas; not becoming indurated.
Female-fertile florets 1. Lemmas naviculate, gibbous on the back; saccate; decidedly firmer than the glumes (papery to crustaceous); smooth, or striate; becoming indurated to not becoming indurated; white in fruit; entire; pointed; crested at the tip; awnless; hairless (smooth, shiny); carinate; having the margins inrolled against the palea; with a clear germination flap; 5 nerved. Palea present; relatively long; entire; awnless, without apical setae; textured like the lemma; indurated, or not indurated; 2-nerved. Lodicules present; 2; free; fleshy; glabrous. Stamens 3. Anthers not penicillate. Ovary glabrous. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit small; compressed laterally. Hilum short. Embryo large; not waisted.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae present, or absent. Intercostal papillae not over-arching the stomata; consisting of one symmetrical projection per cell. Long-cells markedly different in shape costally and intercostally (the costals narrowly rectangular); of similar wall thickness costally and intercostally (very thin walled). Intercostal zones without typical long-cells (these being irregularly equidimensional). Mid-intercostal long-cells having markedly sinuous walls. Microhairs present; panicoid-type; 39–50 microns long; about 4.5 microns wide at the septum. Microhair total length/width at septum about 8.7. Microhair apical cells (17–)18–22(–27) microns long. Microhair apical cell/total length ratio 0.43–0.46. Stomata common. Subsidiaries low dome-shaped, or triangular; including both triangular and parallel-sided forms on the same leaf, or not including both parallel-sided and triangular forms on the same leaf. Guard-cells overlapping to flush with the interstomatals. Intercostal short-cells absent or very rare. Costal short-cells conspicuously in long rows. Costal silica bodies sometimes sharp-pointed, ‘panicoid-type’, or saddle shaped; cross shaped, or butterfly shaped, or dumb-bell shaped; sharp-pointed to not sharp-pointed.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with radiate chlorenchyma; without adaxial palisade; Isachne-type. Leaf blade with distinct, prominent adaxial ribs, or ‘nodular’ in section; with the ribs more or less constant in size. Midrib conspicuous, or not readily distinguishable (rarely); with one bundle only, or having a conventional arc of bundles. Bulliforms present in discrete, regular adaxial groups; in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’. Sclerenchyma all associated with vascular bundles.
Culm anatomy. Culm internode bundles in one or two rings.
Taxonomy. Panicoideae; Panicodae; Isachneae.
Distribution, ecology, phytogeography. 12 species; palaeotropical. Commonly adventive. Mesophytic; shade species. Forests.
Paleotropical and Australian. African, Madagascan, Indomalesian, Polynesian, and Neocaledonian. Sudano-Angolan and West African Rainforest. Indian, Indo-Chinese, Malesian, and Papuan. Fijian. North and East Australian. Sahelo-Sudanian, Somalo-Ethiopian, and South Tropical African. Tropical North and East Australian.
Rusts and smuts. Rusts — Physopella and Puccinia. Taxonomically wide-ranging species: Physopella clemensiae, Puccinia orientalis, and ‘Uromyces’ setariae-italicae.
Economic importance. Significant weed species: C. accrescens, C. oxyphyllum, C. patens. Important native pasture species: e.g. C. patens.
References, etc. Leaf anatomical: Metcalfe 1960 and this project.
Illustrations. • Inflorescence detail
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).
