Three of this group are very common wayside spring flowers. One is the White Dead Nettle (_Lamium album_), with large, white flowers forming whorls in the axils of the leaves. The leaves of this plant are all stalked, cordate, with a very sharp point, deeply serrate, and often marked with white blotches. The teeth of the calyx are narrow, as long as the tube, with long slender points; and the tube of the corolla is curved, longer than the calyx, gradually widening from below upwards. The two lower stamens are longer than the upper pair, and the anthers are black. The plant varies from six to eighteen inches in height, and flowers from April to September. The Red Dead Nettle (_L. purpureum_) grows to the same height, but has much smaller cordate or kidney-shaped leaves, with blunt apices and crenate edges. The upper ones are very crowded, and often tinged with red; and all the leaves are stalked. The flowers are small, of a red-purple colour (rarely white), in crowded whorls in the axils of the upper leaves. The tube of the corolla is straight, longer than the calyx; and the calyx teeth are spreading. [Illustration: THE YELLOW PIMPERNEL.] The third species--the Cut-leaved Dead Nettle (_L. incisum_ or _L. hybridum_)--is not so abundant as the other two, but moderately common on waste land. Its leaves, which are all stalked, are very deeply cut in a serrate manner; the lower ones being cordate, while the upper are more triangular. The flowers are of a rose-red colour, in crowded whorls near the top of the stem. The tube of the corolla is _shorter_ than the calyx, and straight; and the teeth of the calyx are about as long as its tube. The plant grows from six to eighteen inches in height, and flowers throughout the whole of spring and summer. Another common Labiate--the Ground Ivy (_Nepeta Glechoma_)--may be seen almost everywhere in the spring, in bloom from March to May. It has a procumbent, creeping stem, and deeply-crenate, kidney-shaped leaves. The flowers are of a blue-purple colour, arranged in whorls of three or four in the axils of the leaves. The calyx has five teeth and fifteen ribs; and the two front stamens are shorter. [Illustration: THE DOG'S MERCURY.]