brown knapweed and stone bumblebee flying

basilisk bee black bloom blossom bluebonnet bluebottle bluet bluett bombus brown bumblebee bumblebees canada carder centaurea centaury collecting cornflower dusty fieldweed flora flower forb forbs grass harmful herb horseknops humblebee ill jacea knapweed meadow miller persistent pink plant scale scenery summer sun tare tares thistle undesirable vegetation weed wild