Publication: Syst. Veg. 2: 276.
selected vouchers: WS
Notes: H&C locates it on sandbars of Columbia R.
FNA24: "Coleanthus subtilis is an ephemeral pioneer species of wet, open habitats. It grows on wet, muddy to sandy, calcium-deficient soils on the shores of lakes, sandbars, and islands. In the Flora region, it is known from the Columbia River, and around Hatzic, Arrow and Shuswap lakes in British Columbia. It also grows in Europe, Russia, and China. Throughout its range, C. subtilis is known from relatively few, scattered locations. It is easily overlooked because of its diminutive size, and because it flowers in early spring or late fall. It is not clear whether it is native or introduced in the Flora region."