Achnatherum hendersonii (Vasey) Barkworth

Washington: Kittitas: Along Ellensburg-Wenatchee road, 5 mi. S of Chelan Co. line.
46.99667° N, 120.54667° W,
On a gently sloping east-facing hogback about 50 yards wide; apparently restricted to a band across the upper end of the hogback, with more Stipa above and more Oryzopsis below. Associated taxa: Oryzopsis hendersonii (Spellenberg 1768), Stipa lemmonii (Spellenberg 1770). HerbariumSpecimenDuplicate: Oryzopsis hendersonii | herbariumSpecimenDuplicate: Achnatherum hendersonii | herbariumSpecimenDuplicate: Oryzopsis hendersonii X Stipa lemmonii | herbariumSpecimenDuplicate: Achnatherum hendersonii x Achbatherum lemmonii Sometimes growing with both Stipa and Oryzopsis, or with Oryzopsis alone. Other hybrids were near edge of hogback near Agropyron and Festuca, which were not common on the barren top. Plants forming small to large rounded tufts, centers decaying; panicle branches spreading to about 10 degrees or erect. 12 plants were collected. Numbered tags attached to speciments indicate separate individuals collected from the population. Https://intermountainbiota.org/portal/collections/individual/index.php?occid=30814536. Phenology: flowering.

R. Spellenberg 1769, 1967-6-24
With M. Spellenberg
WS, Catalog: 270239