common water-dropwort, stiff cowbane
[Oenanthe ambigua Nutt., more...]
Etymology: Oxypolis: from oxus, "sharp," and polios for "white;" from the awl-shaped, secondary bracts, and white petals.
Plants: erect, perennial, 2'-4' tall, smooth forb with few branches; stems flattened; roots fibrous or thickened tubers
Leaves: few, the wide base clasping the stem; pinnately-divided with 5-9 long and narrow, mostly stalkless leaflets
Flowers: white, 5-parted; inflorescence a few, 3"-6" wide, stalked, compound umbels with 20 or more spreading, loose, open umbellets; blooms July-Sept.
Fruits: dry, both ends rounded, back very flat with 5 rib-like ridges along each side, splitting into 2 seeds that are 2 times as wide as long
Habitat: wet to moist; swamps, marshes, wet prairies, fens
Conservation Status: Native
Floristic Rating: Coefficient of Conservatism = 6, Wetland Indicator = OBL Atlas of the Wisconsin Prairie and Savanna Flora: by T.S. Cochrane & H.H. Iltis: habitat, distribution infomation / flowering and fruiting times USDA Plants Database: Federal Distribution and detailed information including photos Dan Tenaglia's The Missouri Flora: Fabulous photographs; detailed descriptions; color and leave arrangement key.