purplish-blue blooming floss flower shrub in garden by autumnal sunlight

ageratum annual aster asteraceae autumnal beautiful bloom blooming bluemink blueweed botanical bush cluster clusters color colour corymbs dense dwarf floss flower flowering flowers fluff-haired fluffy foot garden grow growing growth herb herbaceous houstonianum lavender mexican ornamental outside paintbrush plant purple purplishblue pussy pussyfoot ray showy shrub sunlight threadlike violet sunny