Scolochloa Link
From the Greek scolos (prickle) and chloa (grass), alluding to excurrent lemma nerves.
Including Fluminia Fries
Habit, vegetative morphology. Perennial; rhizomatous (with succulent rhizomes). Culms 70–200 cm high. Culm internodes hollow. Leaves not basally aggregated; non-auriculate; without auricular setae. Leaf blades linear; broad, or narrow; 4–12 mm wide; flat; not pseudopetiolate; without cross venation; an unfringed membrane; truncate; 3–10 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence paniculate; open (to 30 cm long); espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets 7–11 mm long; compressed laterally; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension naked. Hairy callus present. Callus short; pointed.
Glumes two; very unequal; (the longer) long relative to the adjacent lemmas; hairless; pointed (acute to acuminate); awnless; non-carinate; similar. Lower glume 1–5 nerved. Upper glume 3–7 nerved. Spikelets with female-fertile florets only; without proximal incomplete florets.
Female-fertile florets 3–4. Lemmas similar in texture to the glumes to decidedly firmer than the glumes (somewhat leathery); not becoming indurated; indistinctly incised; 3 lobed (or lacerate); not deeply cleft; awnless, or mucronate; hairless (save for the villous callus); non-carinate; without a germination flap; 5–9 nerved. Palea present; relatively long; 2-nerved; 2-keeled. Lodicules present; free; membranous; glabrous; toothed, or not toothed; not or scarcely vascularized. Stamens 3. Anthers 2–4 mm long. Ovary apically hairy. Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Fruit small (about 2 mm long); compressed dorsiventrally. Hilum long-linear. Embryo small (but nearly 1/3 of the grain length). Endosperm hard; without lipid; containing compound starch grains. 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 similar in shape costally and intercostally; of similar wall thickness costally and intercostally. Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs absent. Stomata common; 33–39 microns long. Subsidiaries parallel-sided and dome-shaped. Guard-cells overlapped by the interstomatals, or overlapping to flush with the interstomatals. Intercostal short-cells in cork/silica-cell pairs; silicified. Costal short-cells predominantly paired. Costal silica bodies horizontally-elongated crenate/sinuous (short), or rounded and crescentic (or more or less rectangular); not sharp-pointed.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma. Bulliforms present in discrete, regular adaxial groups (at the bases of the furrows); in simple fans. Sclerenchyma all associated with vascular bundles.
Cytology. Chromosome base number, x = 7. 2n = 28. 4 ploid. Chromosomes ‘large’.
Taxonomy. Pooideae; Poodae; Poeae.
Distribution, ecology, phytogeography. 2 species; North temperate. Helophytic, or mesophytic. Lakes, rivers, wet meadows.
Holarctic. Boreal, Tethyan, and Madrean. Arctic and Subarctic, Euro-Siberian, and Rocky Mountains. Mediterranean. European and Siberian.
Rusts and smuts. Rusts — Puccinia. Taxonomically wide-ranging species: Puccinia coronata and Puccinia recondita. Smuts from Ustilaginaceae. Ustilaginaceae — Ustilago.
Economic importance. Important native pasture species: S. festucacea.
References, etc. Leaf anatomical: this project; 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).