Achillea

1. Corollas yellow; leaves pinnatifid, with toothed segments.

A. filipendulina

1. Corollas white (or pink); leaves either finely dissected or merely toothed.

2. Leaves finely dissected; rays (1–) 1.2–3 mm long.

A. millefolium

2. Leaves simple, linear-lanceolate, sharply and closely (but finely) toothed; rays ca. 4–6 mm long.

A. ptarmica

All species found in Achillea

Achillea filipendulinaFERN-LEAF YARROW 
Achillea millefoliumYARROW, MILFOIL 
Achillea ptarmicaSNEEZEWORT, SNEEZEWEED 

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. August 20, 2019. https://michiganflora.net/genus.aspx?id=Achillea.