brass buttons (cotula coronopifolia) wildflowers growing in the wetlands of south san francisco bay area, california where is

africa african america asteraceae bloom blooming blossom botanical botany brass band brassbuttons button buttonweed buttons ca california close up closeup common coronopifolia cotula detail field flora floral flower garden golden green invasive leaf many marsh meadow natural nature plant small south united states usa water waterbutton weed wetlands wild wildflower yellow