Publication: Hooker's J. Bot. Kew Gard. Misc. 5: 264. (as microtheca). 1853.
Origin: Native
selected vouchers: WTU
Notes: FNA5: "Variety laxiflorum is the common expression of the species in the northern part of the species\\' range. It occurs in northern Arizona, eastern California, western Colorado, central and southern Idaho, southwestern Montana, Nevada, eastern Oregon, northern and western Utah, eastern Washington, and southwestern Wyoming. It overlaps morphologically with var. simpsonii in northern Arizona. The variety is the primary host plant for the rare Mattoni blue butterfly (Euphilotes rita mattoni)."
References: (none)