The Hemp Agrimony (_Eupatorium cannabinum_), of the order _Compositæ_, is very common along the banks of streams and on the borders of wayside ditches all over Britain. It would hardly be taken for a composite flower by those who are acquainted only with the more typical members of the order, but an examination of its rather dull lilac blossoms will soon reveal its affinity to the other members of the group, for the compact, terminal corymb is formed of numerous small heads, each consisting of about five tubular, perfect florets of equal size, surrounded by an involucre of a few overlapping bracts, and remarkable on account of their projecting styles, which are deeply divided into club-shaped branches. The plant is a large one, with erect, reddish stems, varying from two to six feet in height; and it flowers from July to September. [Illustration: THE HEMP AGRIMONY.] We have already noticed the Lesser Skull-cap (p. 275), which is rather common on damp heaths, and there is another British member of the same genus--the Common Skull-cap (_Scutellaria galericulata_)--that is frequently seen on the banks of streams and in other wet places. The latter is a slightly downy plant, with a creeping stock, and a slender, branched stem from eight to sixteen inches high. Its leaves are opposite, as in other plants of the same order (_Labiatæ_), with very short stalks, and crenate or slightly-toothed edges. The flowers are in pairs in the axils of the leaves, almost sessile, and all turned towards the same side of the stem. On the back of the two-lipped calyx is a hollow, scale-like projection which gave rise to the popular name, for when the corolla falls, the lips of the calyx close over the ripening fruit, and the projection above mentioned then presents somewhat the appearance of a cap. The corolla is over half an inch long, of a dull blue colour without, but much paler inside. This plant flowers from July to September. On the banks of streams and ditches we may often meet with the Comfrey (_Symphytum officinale_)--a coarse and rough but pretty plant belonging to the _Boraginaceæ_. It has a stout, branching stem, two or three feet high; and the stem-leaves extend downward on its surface forming wing-like ridges. The lower leaves are stalked, broader than the upper ones, generally from six to eight inches long; and all the leaves are rough with bristly hairs. The flowers are of a yellowish white or, sometimes, of a purple colour, and are arranged in forked, drooping, one-sided racemes. The calyx is deeply cleft into five lobes; and the corolla consists of a tubular portion, the top of which is closed by five narrow, fringed scales; and, above this, a wider bell-shaped part, of about the same length, with five small, reflexed teeth. This plant blooms during May and June. [Illustration: THE COMMON SKULL-CAP.]