Littledalea Hemsley
Habit, vegetative morphology. Robust perennial; rhizomatous. Culms 12–35 cm high; herbaceous. Leaves non-auriculate. Sheath margins free (for at least three quarters of the lengths of the sheaths). Leaf blades linear; narrow; 1–4 mm wide; flat, or rolled (convolute); without cross venation; an unfringed membrane; not truncate; 0.5–3.5 mm long.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence paniculate; open; espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes persistent. Spikelets not secund; pedicellate.
Female-fertile spikelets. Spikelets 18–35 mm long (i.e., large); purplish, papery; compressed laterally; disarticulating above the glumes; disarticulating between the florets; with conventional internode spacings. Rachilla prolonged beyond the uppermost female-fertile floret; hairless; the rachilla extension with incomplete florets. Hairy callus absent. Callus short; blunt.
Glumes two; very unequal; shorter than the adjacent lemmas; hairless; glabrous; pointed to not pointed; awnless; non-carinate; similar. Lower glume 1–3 nerved. Upper glume 5 nerved, or 7 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped; awnless. Spikelets without proximal incomplete florets.
Female-fertile florets 7–9. Lemmas apically rounded or erose; similar in texture to the glumes; not becoming indurated; incised; pointed to blunt; when incised, 2 lobed; not deeply cleft; awnless, or mucronate to awned. Awns when present, 1; median; from a sinus; non-geniculate; hairless; much shorter than the body of the lemma; entered by one vein. Lemmas hairless; scabrous; non-carinate; without a germination flap; 5–7 nerved; with the nerves non-confluent. Palea present; conspicuous but relatively short (about half the lemma length); tightly clasped by the lemma; apically notched; awnless, without apical setae; textured like the lemma; not indurated; 2-nerved; 2-keeled. Palea keels wingless; scabrous. Lodicules present; 2; free; membranous; ciliate, or glabrous; toothed; not or scarcely vascularized. Stamens 3. Anthers 6–7 mm long; not penicillate; without an apically prolonged connective. Ovary apically hairy; without a conspicuous apical appendage (not at all Bromus-like, in material seen). Styles free to their bases. Stigmas 2.
Fruit, embryo and seedling. Endosperm containing only simple starch grains.
Abaxial leaf blade epidermis. Costal/intercostal zonation lacking. 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 (rather thick, pitted). Microhairs absent. Stomata absent or very rare (none seen). Intercostal short-cells common; in cork/silica-cell pairs (frequent pairs, but no silica bodies in the ‘silica cells’); not silicified. Costal short-cells predominantly paired (some solitary). Costal silica bodies absent.
Transverse section of leaf blade, physiology. C3; XyMS+. Mesophyll with non-radiate chlorenchyma; without adaxial palisade. Leaf blade with distinct, prominent adaxial ribs; with the ribs more or less constant in size to with the ribs very irregular in sizes. Midrib not readily distinguishable; with one bundle only. Bulliforms not present in discrete, regular adaxial groups. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with the primaries only, the rest with strands); forming ‘figures’ (in the primaries). Sclerenchyma all associated with vascular bundles.
Cytology. Chromosomes ‘large’.
Taxonomy. Pooideae; Poodae (or Triticodae?); Poeae (?).
Distribution, ecology, phytogeography. 3 species; central Asia to western China. Mesophytic to xerophytic; species of open habitats. Stony slopes.
Holarctic. Tethyan. Irano-Turanian.
References, etc. Leaf anatomical: this project.
Special comments. Morphological description revised by E.A. Kellogg, November 1988. Fruit data wanting.
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).