Echinopogon P. Beauv.
From the Greek echinos (hedgehog) and pogon (beard), referring to the inflorescence.
Including Hystericina Steud.
Habit, vegetative morphology. Perennial; rhizomatous, or caespitose. Culms herbaceous. Culm nodes glabrous. Culm internodes solid, or hollow. Leaves not basally aggregated; non-auriculate. Leaf blades narrow; without cross venation; persistent; an unfringed membrane; truncate; 1.5–3 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence paniculate; contracted; capitate, or more or less ovoid. Primary inflorescence branches borne distichously. Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets 2.5–10 mm long; compressed laterally; disarticulating above the glumes. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension naked. Hairy callus present.
Glumes two; relatively large; more or less equal; long relative to the adjacent lemmas; pointed (acute to acuminate); awnless; carinate (the keels stiffly ciliate); similar (membranous). Lower glume 1 nerved. Upper glume 1 nerved, or 3 nerved. Spikelets with female-fertile florets only; without proximal incomplete florets.
Female-fertile florets 1. Lemmas decidedly firmer than the glumes (thinly leathery); not becoming indurated; incised; 2 lobed (the apex narrow, with two slender, erect, acuminate or setiform lateral lobes); mucronate (E. phleoides), or awned. Awns 1; median; from a sinus (or slightly behind it); non-geniculate; hairless (scabrid); entered by one vein. Lemmas hairless; non-carinate; distinctly 5–7(–11) nerved. Palea present; relatively long; minutely apically notched (3-toothed); 2-nerved; 2-keeled, or keel-less. Lodicules present; 2; free; membranous; ciliate; not toothed. Stamens 3. Anthers not penicillate. Ovary glabrous, or hairy. Styles free to their bases. Stigmas 2; white.
Fruit, embryo and seedling. Fruit free from both lemma and palea; small; longitudinally grooved; not noticeably compressed; glabrous, or hairy; with hairs confined to a terminal tuft. Hilum long-linear. Embryo small; not waisted. Endosperm liquid in the mature fruit, or hard; containing compound starch grains. Embryo with an epiblast; without a scutellar tail; with a negligible mesocotyl internode. Embryonic leaf margins meeting.
Seedling with a short mesocotyl. First seedling leaf with a well-developed lamina. The lamina narrow; erect; 3–5 veined.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells similar in shape costally and intercostally (elongated); of similar wall thickness costally and intercostally. Mid-intercostal long-cells rectangular to fusiform; having straight or only gently undulating walls. Microhairs absent. Stomata common. Subsidiaries parallel-sided, or dome-shaped. Guard-cells overlapped by the interstomatals. Intercostal short-cells common (mainly adjacent to the costal regions), or absent or very rare; in cork/silica-cell pairs (usually), or not paired (sometimes solitary); silicified (when paired), or not silicified. Costal short-cells conspicuously in long rows, or neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies horizontally-elongated crenate/sinuous, or horizontally-elongated smooth (a few, rectangular), or tall-and-narrow.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma. Midrib not readily distinguishable; with one bundle only. Bulliforms present in discrete, regular adaxial groups; in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; nowhere forming ‘figures’. Sclerenchyma all associated with vascular bundles.
Cytology. Chromosome base number, x = 7. 2n = 42.
Taxonomy. Pooideae; Poodae; Aveneae. Hedgehog grasses.
Distribution, ecology, phytogeography. 7 species; Australia, New Zealand, New Guinea. Mesophytic; glycophytic. In open woodland.
Paleotropical, Australian, and Antarctic. Indomalesian. Papuan. North and East Australian. New Zealand. Tropical North and East Australian and Temperate and South-Eastern Australian.
Rusts and smuts. Rusts — Puccinia. Taxonomically wide-ranging species: Puccinia graminis.
References, etc. Morphological/taxonomic: Hubbard 1935. Leaf anatomical: this project.
Illustrations. • General aspect and spikelet details. • Ligule. • Abaxial epidermis of leaf blade. Echinopogon cheelii.
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).
