Western cowbane is a perennial, tuberous herb in the Apiaceae that is found in open or forested wetland habitats in western North America, in California, Oregon and British Columbia (Roemer 2014, USDA 2014). It was discovered in BC in Haida Gwaii in 2001 by MIchael Cheney, and in 2007 on Vancouver Island by S. Saunders but was collected as early as 1976 on Vancouver Island by Adolf Cecka (Roemer 2014).

"It is only due to the disappearance of some Adolf Ceska's specimens that Oxypolis occidentalis did not become known on Vancouver Island 25 years before it was discovered on Haida Gwai. In 1976 Adolf and Oluna Ceska and Hans Roemer visited a mountainous area on the east side of Vancouver Island’s Beaufort Range where A. Ceska collected what can now be confidently named Oxypolis occidentalis." (Roemer 2014).

Roemer (2014) indicates that Oxypolis may be confused with Berula, Cicuta, Sium and the introduced Pastinaca, and that most occurrences are in sedge-dominated wetlands.

References:

Roemer, Hans 2014. Oxypolis occidentalis on Vancouver Island, British Columbia. Botanical Electronic News 482.

USDA. 2014. Plant Profile for Oxypolis occidentalis. Plants Database. United States Department of Agriculture, Natural Resources Conservation Section