Pseudoroegneria (Nevski) A. Löve
Sometimes referred to Elymus, Elytrigia
Habit, vegetative morphology. Perennial; caespitose. Culms 30–90 cm high; herbaceous; unbranched above. Young shoots intravaginal. Leaves not basally aggregated; auriculate. Leaf blades linear; narrow; flat, or rolled (involute or convolute); without cross venation; persistent; an unfringed membrane; truncate. Contra-ligule absent.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets; outbreeding.
Inflorescence. Inflorescence a single spike (the spikelets appressed). Rachides hollowed (against the spikelet). Inflorescence espatheate; not comprising ‘partial inflorescences’ and foliar organs. Spikelet-bearing axes usually persistent; fragile or not in P. stipifolia, where the spikelet may fall with the internode above. Spikelets solitary; not secund; distichous; sessile to subsessile; not imbricate (at least, the spikes lax by contrast with Elymus).
Female-fertile spikelets. Spikelets 18–22 mm long; compressed laterally; disarticulating above the glumes; not disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; hairless (glabrous); the rachilla extension with incomplete florets. Hairy callus present (inconspicuous). Callus short; blunt.
Glumes two; very unequal to more or less equal; shorter than the spikelets; shorter than the adjacent lemmas to long relative to the adjacent lemmas; lateral to the rachis; hairless (sometimes with a few spinules apically); pointed to not pointed (lanceolate or narrowly lanceolate); not subulate; awnless (but sometimes acuminate); non-carinate; similar. Lower glume 5–7 nerved. Upper glume 5–7 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped. Spikelets without proximal incomplete florets.
Female-fertile florets 3–5. Lemmas linear-lanceolate; similar in texture to the glumes; entire; pointed; awnless, or awned. Awns when present, 1; apical; non-geniculate; recurving (widely divergent at maturity); much shorter than the body of the lemma to much longer than the body of the lemma (up to 30 mm long); entered by several veins. Lemmas hairless; glabrous, or scabrous; non-carinate; without a germination flap; 5 nerved; with the nerves confluent towards the tip. Palea present; relatively long (about equalling the lemma); awnless, without apical setae; thinner than the lemma; not indurated; 2-nerved; 2-keeled. Palea keels wingless. Lodicules present; 2; free; membranous; ciliate; not toothed. Stamens 3. Anthers 4–7 mm long. Ovary hairy. Styles free to their bases. Stigmas 2; white.
Fruit, embryo and seedling. Fruit adhering to lemma and/or palea; medium sized; longitudinally grooved; compressed dorsiventrally; with hairs confined to a terminal tuft. Hilum long-linear. Embryo small.
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 (walls of medium thickness). Mid-intercostal long-cells rectangular; having markedly sinuous walls (and pitted). Microhairs absent. Stomata common; (36–)37–39(–42) microns long. Subsidiaries predominantly parallel-sided. Guard-cells overlapped by the interstomatals (mostly, slightly). Intercostal short-cells common (abundant); in cork/silica-cell pairs and not paired (commonly solitary). Costal short-cells predominantly paired. Costal silica bodies rounded (mostly), or saddle shaped to crescentic (few, intergrading with the rounded forms); not sharp-pointed.
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 very irregular in sizes (small, round topped alternating with large, flat topped). Midrib not readily distinguishable; with one bundle only. Bulliforms present in discrete, regular adaxial groups (in all the furrows); in simple fans. All the vascular bundles accompanied by sclerenchyma. Combined sclerenchyma girders present (with most of the major bundles); forming ‘figures’ (I’s with all the major bundles). Sclerenchyma all associated with vascular bundles.
Cytology. Chromosome base number, x = 7. 2n = 14 and 28. 2 and 4 ploid. Haplomic genome content S.
Taxonomy. Pooideae; Triticodae; Triticeae.
Distribution, ecology, phytogeography. About 16 species; Middle East, central Asia, northern China, western North America. Xerophytic; species of open habitats. Drought tolerant.
Holarctic. Boreal and Tethyan. Euro-Siberian, Eastern Asian, Atlantic North American, and Rocky Mountains. Irano-Turanian. European and Siberian. Canadian-Appalachian.
Rusts and smuts. Rusts — Puccinia.
References, etc. Morphological/taxonomic: Löve 1984. Leaf anatomical: this project.
Illustrations. • Spikelet tip
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).
