Symphyotrichum subsect. Occidentales (syn: Aster subsect. Foliacei) includes 11 species of x=8 asters native to western North America. The Foliacei asters usually have phyllaries that often are spreading to reflexed and have a somewhat to considerably enlarged and foliaceus (leafy) apex. The leaves also usually more or less clasp the stem. The Foliacei asters were thought to be closely related to the Symphyotrichum/Puncei asters of eastern North America but this is not supported by molecular studies.