3. The Common St. John's-Wort (_H. perforatum_).--A very common plant in woods and thickets, growing from one to two feet high, and flowering from July to September. It has short, underground stems, or barren shoots that lie on the ground and root at the nodes, in addition to the erect, flowering stems, which are either round or two-edged, and branched towards the top. The leaves are half an inch long, with opaque veins, many transparent dots, and sometimes a few black dots on the under side. The yellow flowers form a terminal corymb. Their sepals are narrow, about half the length of the petals. The stamens are in three sets, united at the base; and both petals and anthers are marked with black dots. 4. The Hairy St. John's-Wort (_H. hirsutum_).--A stiff, erect plant, from one to three feet high, common in the woods and thickets of most parts of Britain, flowering in July and August. The stem is round, and clothed with soft hairs. The leaves are ovate, oblong or elliptical, tapering at the base into a short stalk, about an inch long, with many transparent dots, and downy along the veins on the under side. The sepals are narrow, acute, about half the length of the yellow petals, and fringed with stalked glands. The stamens are in three sets. [Illustration: THE DYER'S GREEN-WEED.] The Wood Crane's-bill (_Geranium sylvaticum_--order _Geraniaceæ_), one of the most handsome of our Wild Geraniums, is not found in the South, but is moderately common in parts of North Britain, including North Ireland. Its stem is erect, from one to two feet high, and branched towards the top. In general form the leaves are heart-shaped or shield-shaped, but they are very deeply divided into five or seven radiating, cut, and toothed lobes. The lower ones are on long stalks; but the upper are shortly stalked or sessile, and less divided. The flowers are of a bluish-purple or rose colour, about an inch in diameter, arranged in a loose panicle with two flowers on each pedicel. The five sepals are about half the length of the petals, and terminate in a very fine point; and the petals are obovate and slightly notched. The plant flowers during June and July. [Illustration: THE SWEET MILK VETCH.]