Eremium Seberg and Linde-Laursen
Latin eremium, ‘small desert’, re ability of the type species to withstand extreme drought.
Sometimes referred to Elymus
Habit, vegetative morphology. Perennial; caespitose. Culms 30–70 cm high; herbaceous; unbranched above. Culm nodes glabrous (brownish). Culm leaves present. Young shoots intravaginal. Leaves not basally aggregated; auriculate. Sheath margins free (?). Sheaths usually covering most of the internodes, pubescent to glabrescent. Leaf blades linear; broad to narrow; (2–)7–14.5(–20) mm wide; (in-) rolled; without cross venation (?); persistent; a fringed membrane (sic, ‘with a fringe of hairs’); truncate; 0.3–1 mm long. Contra-ligule absent.
Reproductive organization. Plants bisexual, with bisexual spikelets; with hermaphrodite florets. The spikelets hermaphrodite. Plants inbreeding.
Inflorescence. Inflorescence a single spike, or a false spike, with spikelets on contracted axes (since the spikelets are not all solitary). Spikelets solitary and paired; not secund; distichous; sessile to subsessile; imbricate.
Female-fertile spikelets. Spikelets 10–20 mm long (and 2–4 mm wide); not described re orientation; compressed laterally; disarticulating above the glumes; disarticulating between the florets. Rachilla prolonged beyond the uppermost female-fertile floret; hairless (glabrous); the rachilla extension with incomplete florets (terminated by an empty lemma).
Glumes two; more or less equal; shorter than the spikelets to about equalling the spikelets; long relative to the adjacent lemmas (about 10–20 mm long); lateral to the rachis (? - not specified); hairless; glabrous, or scabrous (on the nerves); pointed; (linear-) subulate; awned (awnlike); similar. Lower glume 1(–3) nerved. Upper glume (1–)3 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets 1, or 2; merely underdeveloped. Spikelets without proximal incomplete florets.
Female-fertile florets 1–3(–5). Lemmas entire (?); awned. Awns 1; median; apical (? - not described, illustration not reliably interpretable); non-geniculate; straight; hairless; much shorter than the body of the lemma to about as long as the body of the lemma (1.8–10.2 mm long). Awn bases not twisted; not flattened. Lemmas hairy (the margins densely ciliate, and sometimes hairy abaxially as well); without a germination flap; 5–7 nerved; with the nerves confluent towards the tip. Palea present; relatively long; entire to apically notched; awnless, without apical setae; 2-nerved; 2-keeled. Lodicules present; 2; free; membranous; ciliate. Stamens 3. Anthers 2.2–4 mm long; not penicillate; without an apically prolonged connective. Ovary hairy. Stigmas 2.
Fruit, embryo and seedling. Fruit adhering to lemma and/or palea, or free from both lemma and palea (? - not mentioned); medium sized (5.5 mm long); not grooved; smooth (?). Hilum long-linear (?!). Embryo small.
Cytology. Chromosome base number, x = 7. 2n = 42. 6 ploid. Haplomic genome content uncertain, but lacks S and H genomes. Chromosomes large.
Taxonomy. Pooideae; Triticodae; Triticeae.
Distribution, ecology, phytogeography. 1 species (E. erianthus); Argentina. Xerophytic; species of open habitats.
Neotropical. Pampas and Andean.
Hybrids. Possible hybridization with Elymus glaucescens.
References, etc. Morphological/taxonomic: Seberg ansd Linde-Laursen (1996).
Special comments. The morphological description is fairly inadequate (e.g. lacking information on sheath margins, spikelet orientation, fruit), and if the ‘fringed ligule’ is an error of interpretation, the difference from Elymus is limited to the long-ciliate lemmas, the genome, and geographical distribution. Fruit data wanting. Anatomical 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).