common beggarticks (bidens frondosa). flowering capitulum closeup

asteraceae bidens frondosa compositae androecium anther anthesis bur marigold calicular bract calycle campanulate capitulum common beggarticks connate corolla devil 039 bootjack pitchfork disc floret filament flower gynoecium head hirsute indumentum inflorescence involucral involucre leafy phyllary pistil weed pollen stamen sticktights stigma style tickseed sunflower tubular ray ligulate frondosa flowering closeup virtual herbarium belarus flora: focus-stacked closeups wild cultivated plants including flowers leaves fruits intended illustrations botanical manuals