Erythranthera Zotov
Sometimes referred to Rytidosperma, Danthonia sensu lato
Habit, vegetative morphology. Perennial; rhizomatous, or caespitose, or decumbent (often sward-forming). Culms 3–12 cm high; herbaceous. Culm nodes glabrous. Culm internodes hollow. Leaves mostly basal; non-auriculate. Leaf blades narrow; setaceous; flat, or folded (to 3 cm long); without cross venation; disarticulating from the sheaths; a fringed membrane (very short), or a fringe of hairs.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence few spikeleted; a single raceme, or paniculate; open, or contracted; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets 2.5–5 mm long; compressed laterally; disarticulating above the glumes; with distinctly elongated rachilla internodes between the florets (internodes up to 1/3 as long as the lemmas). Rachilla prolonged beyond the uppermost female-fertile floret. Hairy callus absent. Callus short; blunt (flattened).
Glumes two; more or less equal; long relative to the adjacent lemmas; free; awnless; similar. Lower glume 3–5 nerved. Upper glume 3 nerved. Spikelets with female-fertile florets only, or with incomplete florets. The incomplete florets distal to the female-fertile florets.
Female-fertile florets 3–5. Lemmas not becoming indurated; incised; minutely 3 lobed; not deeply cleft (with 3 minute apical teeth); awnless; hairy, or hairless (glabrous). The hairs when present, not in tufts; not in transverse rows (scattered). Lemmas carinate to non-carinate; 7–9 nerved. Palea present; 2-nerved; 2-keeled. Palea keels hairy (ciliate). Lodicules present; 2; joined, or free; fleshy, or membranous; glabrous; toothed. Stamens 3. Anthers not penicillate. Ovary glabrous. Styles free to their bases. Stigmas 2; brown.
Fruit, embryo and seedling. Fruit small. Hilum short. Embryo large. Endosperm containing compound starch grains. Embryo without an epiblast; with a scutellar tail; with an elongated mesocotyl internode.
Ovule, embryology. Micropyle not noticeably oblique. Outer integument covering no more than the chalazal half of the ovule; more than two cells thick at the micropylar margin. Inner integument discontinuous distally; not thickened around the micropyle. Synergids haustorial; exhibiting large, globular starch grains.
Abaxial leaf blade epidermis. Costal/intercostal zonation conspicuous. Papillae absent. Long-cells similar in shape costally and intercostally (long and narrow); of similar wall thickness costally and intercostally (thick walled). Mid-intercostal long-cells rectangular; having markedly sinuous walls. Microhairs present; panicoid-type; 45–55.5(–60) microns long; 9.6–14.4 microns wide at the septum. Microhair total length/width at septum 3.1–5.8. Microhair apical cells 24–36 microns long. Microhair apical cell/total length ratio 0.43–0.59. Stomata absent or very rare. Subsidiaries dome-shaped, or triangular. Intercostal short-cells common; in cork/silica-cell pairs; silicified. Intercostal silica bodies mainly crescentic. Costal short-cells conspicuously in long rows, or neither distinctly grouped into long rows nor predominantly paired. Costal silica bodies rounded (including potato-shaped), or crescentic, or ‘panicoid-type’.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with radiate chlorenchyma, or with non-radiate chlorenchyma; without adaxial palisade. Leaf blade with distinct, prominent adaxial ribs, or adaxially flat; with the ribs more or less constant in size. Midrib conspicuous, or not readily distinguishable; with one bundle only. Bulliforms present in discrete, regular adaxial groups (in the furrows); in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present; forming ‘figures’. Sclerenchyma all associated with vascular bundles.
Taxonomy. Arundinoideae; Danthonieae.
Distribution, ecology, phytogeography. 3 species; Australia, New Zealand. Species of open habitats. Alpine.
Australian and Antarctic. North and East Australian. New Zealand. Temperate and South-Eastern Australian.
References, etc. Morphological/taxonomic: Zotov 1963. 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).