bitter fleabane or the erigeron acris

acer acris anther anthesis asteraceae background beautiful belarus bitter black blade blue botanical botany bract capitulum ciliate closeup compositae connate entire erigeron fleabane flora floret flower flowers focus head herbarium inflorescence involucral involucre lamina lanceolate leaf ligulate ligule macro margin natural nature oblong peduncle petiole phyllary pistil plant plants pollen ray science seeds stacking stamen stigma style tubular undefined venation virtual