Eaton's Aster (Symphyotrichum bracteolatum)

More size information here.

A shorter aster for moist areas!

Eaton’s Aster is on the shorter side for an Aster, and loves moist sunny places. It is commonly found across Western North America in seasonally wet areas, where it grows to about 3 feet. It typically has white flowers, which can be pinkish or purplish. This is an excellent late-season pollinator plant! In wet areas, it will tend to spread by underground rhizomes.

"eaton's aster" by Rob Irwin