The digitalis, wild arum, hyacinth, strawberry, goldenrod, lily of the valley, and other plants common to temperate zones grow in abundance. Beech and oak are the predominant trees. Among mammals still found in Belgium are the boar, fox, badger, squirrel, weasel, marten, and hedgehog. The many varieties of aquatic life include pike, carp, trout, eel, barbel, perch, smelt, chub, roach, bream, shad, sole, mussels, crayfish, and shrimp.