Publication: Trans. Linn. Soc. London. 17: 407. 1836.
Origin: Native
selected vouchers: WTU
Notes: FNA5: "Variety sphaerocephalum is common and widespread in eastern Washington, eastern Oregon, and southwestern Idaho, less so in northern and central-western Nevada, and infrequent in California. A collection supposedly obtained in 1883 from the "Flathead region" of Montana (Ayres s.n., NY) is discounted as to location."
References: (none)