Eriosella caduca (Beal) Romasch., comb. 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 caduca (Beal) Romasch., comb. nov.

Oryzopsis caduca Beal, Bot. Gaz. 15(5): 111. 1890 [Basionym] ≡ Eriocoma caduca (Beal) Rydb., Mem. New York Bot. Gard. 1: 25. 1900 ≡ Stipa caduca (Beal) Scribn., Contr. U.S. Natl. Herb. 3(1): 54. 1892 ≡ × Stiporyzopsis caduca (Beal) B.L. Johnson & Rogler, Amer. J. Bot. 30: 55, f. 10, 14, 28-33. 1943 ≡ × Achnella caduca (Beal) Barkworth, Phytologia 74(1): 15. 1993. Type: USA, Montana, Belt Mts., Sixteen Mile Cr., 11 Jul 1883, F.L. Scribner s.n. (holotype: US-745838!).

Comments.

× Eriosella caduca is thought to be a hybrid between Eriocoma hymenoides and Nassella viridula . It can be separated from E. hymenoides in having shorter hairs on the lemma and panicles with ascending branches (not divergent), and from N. viridula in having longer lemma hairs, paleas 2/3-3/4 as long as the lemma, and readily deciduous lemmatal awns ( Barkworth 2007). Another species similar to × Eriosella caduca is Eriocoma bloomeri . However, the latter species has glabrous sheaths, shorter ligules, 5-veined lemmas, awns with a sub-plumose lower section below the bend, and anthers with more numerous apical hairs ( Johnson and Rogler 1943).