Oldfield Hairy White Aster

Symphyotrichum pilosum var. pilosum is very common in southern Ontario and throughout much of the eastern United States.  It becomes much less common in southern Québec.  Stem height is highly variable depending upon growing conditions.  The stems are always hairy (Brouillet et al 2006 FNA).  Inflorescences vary from large open pyramidal arrays with many heads to small more racemiform arrays with few heads depending upon growing conditions.  Two ploidy levels occur influencing involucre and floret size: tetraploid (2n=32) and hexaploid (2n=48) with the hexaploids confined to glaciated areas.  Tetraploids occur through much of the range.

Rarely pinkish rayed forms occur.