achene Asteraceae clock close-up.macro compositae damage Dandelion fly herb medical pericarp plant summer Taraxacum wind wishie blow dandylion flower flowering garden grass lawn seed seeding seeds spring weed weeds wish copyspace blue sky sphere achenes ball common dandelion clock dispersal head parachute ball pattern puff puff ball puffs round spherical spread spreading Taraxacum officinale texture widespread wind-aided wind-blown wind-spread