current dangerous fall fierce flow gully natural nature norway norwegian powerful rock strong violent water waterfall blue cloud flat green holland land landscape Netherlands Petten rural sky summer white windy bark Betula birch England english epiphyte Great Britain heathland lichen plant Surrey tree trunk bush Cacti cactus Greece Greek invader mountains naturalised opuntia pear Prickly spring wild algae aquatic background bladderwrack canada coast littoral marine pacific seaweed shore texture vancouver sea grass kent panorama peace view lake reservoir ripple sailing water Sussex water supply Dandelion flower head petal Taraxacum uk united kingdom yellow barley crop farm field Hordeum