© John Crellin (Photo ID #19884)
Achillea ptarmica is a summer flowering perennial garden species that originates in Europe and Asia where it occurs in wet meadows, marshes and streambanks. It has now naturalized in some Canadian provinces (AB, LB, MB, NB, NF, NS, ON, PE, QC) and in some northern US states (AK, CT, ID, IN, MA, ME, MI, MN, MT, NH, NJ, NY, OH, PA, RI, VT, WA, WI, WV) (USDA 2010). This is a very hairy, erect rhizomatous species, ½ to 3 feet tall, with numerous white daisy-like flowers in flat-topped inflorescences, and entire, toothed, 1/2 to 2 inch long, leaves (Alaska Natural Heritage Program 2005). In North America, it is found in disturbed sites, including fields and pastures, and in sandy or gravelly or silty soils at 0–2400 m elevation (Trock 2010). It reproduces both sexually and asexually (underground runners), and shows some preference for moist, well drained soils, with pH ranging from neutral to slightly acidic (Alaska Natural Heritage Program 2005). The first record of this species in the UBC Herbarium is a collection by D. Faris Jr. in 1954, from Langley Prairie. There is a second collection record from Wells Gray Park in 1992 by Frank Lomer.
Two species of Achillea in BC may be confused: Achillea millefolium and A. sibirica. The third species, A. ptarmica, is distinctive, with few, larger flowerheads.
Key to A. millefolium and A. sibirica:
1. Leaves pinnately dissected, the divisions again dissected; plants widespread in BC......................A. millefolium
1. Leaves incised, the divisions of the latter merely toothed; plants of northeastern BC.......................A. sibirica
Source: Illustrated Flora of British Columbia
Trock, Debra K. 2010. Achillea ptarmica. Flora North America. Available Online.
USDA. 2010. Plant Profile for Achillea ptarmica. United States Department of Agriculture Plants Database. Available Online.