Eriosella Romasch., nothogen. nov.

Peterson, Paul M., Romaschenko, Konstantin, Soreng, Robert J. & Reyna, Jesus Valdes, 2019, A key to the North American genera of Stipeae (Poaceae, Pooideae) with descriptions and taxonomic names for species of Eriocoma, Neotrinia, Oloptum, and five new genera: Barkworthia, x Eriosella, Pseudoeriocoma, Ptilagrostiella, and Thorneochloa, PhytoKeys 126, pp. 89-125 : 97

× Eriosella Romasch., nothogen. nov.

Eriocoma Nutt. × Nassella (Trin.) E. Desv. Type: × Eriosella caduca (Beal) Romasch. (≡ Oryzopsis caduca Beal)

Description.

Plants perennial, cespitose, not rhizomatous. Culms up to 90 cm tall, nodes glabrous. Leaf sheaths mostly glabrous, margins sparsely ciliate, hairs longer apically; collars glabrous or with tufts of hairs; ligules 0.5-1.7 mm long, scarious, glabrous, apex truncate to obtuse; blades 1-3.5 mm wide, flat to convolute when dry, apices narrowly acute; basal blades to 40 cm long; flag blades longer than 10 cm. Panicles 15-18 cm long, narrow, branches ascending. Spikelets 6-8.5 mm long, fusiform, with one fertile floret without rachilla extension, disarticulation above the glumes; glumes 6-8.5 mm long, longer than the florets, saccate-lanceolate, 3-5-veined, apices attenuate from about the middle; upper glumes slightly narrower than the lower; florets 4-5 mm long, fusiform; calluses about 0.7 mm long, blunt; lemmas 7-veined, coriaceous, evenly hairy throughout, the hairs 1-2 mm long, apex minutely lobed; lemmatal awns 9-16 mm long, twisted, straight or 1-geniculate, readily deciduous, lower portion scabrous and without hairs; paleas 2.5-3.3 mm long, 2/3-3/4 as long as the lemma, hairy; stamens 2, anthers 1.2-2.3 mm long, variable in length within the floret, 2 in number indehiscent, penicillate, with only a few apical hairs. Caryopses not seen.

Etymology.

The name, × Eriosella , is a combination of the prefix ‘Erio’ from Eriocoma and the suffix ' sella ' from Nassella .

Distribution.

Known only from Montana, North Dakota, and western Wyoming ( Johnson and Rogler 1943; Barkworth 2007).