Erianthecium L. Parodi
Alluding to hairy florets.
Habit, vegetative morphology. Perennial; caespitose. Culms 30–45 cm high; herbaceous; tuberous. Culm nodes glabrous. Leaves non-auriculate. Leaf blades linear; narrow; 3–5 mm wide; flat; without cross venation; an unfringed membrane; truncate to not truncate; 3–4 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets; exposed-cleistogamous; without hidden cleistogenes.
Inflorescence. Inflorescence few spikeleted (8–12); paniculate; contracted; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets 7–8 mm long; compressed laterally; disarticulating above the glumes; disarticulating between the florets; with conventional internode spacings. Rachilla prolonged beyond the uppermost female-fertile floret; hairless. Hairy callus absent.
Glumes two; relatively large; very unequal to more or less equal (the upper somewhat longer); shorter than the spikelets; long relative to the adjacent lemmas; hairless; glabrous; pointed (acute); awnless; carinate; similar (lanceolate-acute, papery). Lower glume somewhat shorter than the lowest lemma; 3 nerved, or 5 nerved. Upper glume 7 nerved. Spikelets with female-fertile florets only, or with incomplete florets. The incomplete florets if present, distal to the female-fertile florets. The distal incomplete florets if present, merely underdeveloped. Spikelets without proximal incomplete florets.
Female-fertile florets 3–5. Lemmas similar in texture to the glumes (papery or leathery); not becoming indurated; entire (according to the original description), or incised (according to Clayton and Renvoize 1986); if incised, 2 lobed; not deeply cleft (bidentate, according to Clayton and Renvoize); awned. Awns 1; median; dorsal (according to the original description), or from a sinus (or from behind it?); from near the top; non-geniculate; hairless; much shorter than the body of the lemma to about as long as the body of the lemma; entered by one vein. Lemmas densely hairy; non-carinate; without a germination flap; 7 nerved, or 9 nerved. Palea present; relatively long; tightly clasped by the lemma; apically notched; awnless, without apical setae; textured like the lemma; not indurated; 2-nerved; 2-keeled. Palea back hairy. Palea keels wingless; hairy (long-ciliate). Lodicules present; 2; free; membranous; glabrous; not toothed; not or scarcely vascularized. Stamens 3. Anthers about 1.5 mm long; not penicillate; without an apically prolonged connective. Ovary glabrous. Styles free to their bases. Stigmas 2 (‘pubescent, terminally exserted’).
Fruit, embryo and seedling. Fruit small (1 mm long); ellipsoid to subglobose; compressed dorsiventrally (dorsally convex, ventrally flat). Hilum short. Embryo small. Endosperm liquid in the mature fruit, or hard; with lipid; containing compound starch grains. Embryo with an epiblast.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells markedly different in shape costally and intercostally; of similar wall thickness costally and intercostally. Mid-intercostal long-cells fusiform; having straight or only gently undulating walls. Microhairs absent. Stomata absent or very rare. Intercostal short-cells absent or very rare. Macrohair bases common. Costal short-cells neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies horizontally-elongated crenate/sinuous, or rounded (a few), or ‘panicoid-type’ (some); when panicoid type, mainly cross shaped and nodular (the latter elongated).
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma. Leaf blade ‘nodular’ in section to adaxially flat; with the ribs more or less constant in size. Bulliforms present in discrete, regular adaxial groups; in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present. Sclerenchyma all associated with vascular bundles.
Taxonomy. Pooideae; Poodae; Poeae.
Distribution, ecology, phytogeography. 1 species; Uruguay. Species of open habitats. Stony slopes.
Neotropical. Pampas.
References, etc. Morphological/taxonomic: Parodi 1938. 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).