The Yellow Loosestrife (_Lysimachia vulgaris_), of the order _Primulaceæ_ is a beautiful river-side plant, common in most parts, flowering during July and August. Its stem is stout, erect, branched, slightly downy, from two to three feet high; and its leaves are ovate or lanceolate, sessile, and arranged in opposite pairs or in whorls of three or four. The flowers are rather large, of a bright yellow colour, dotted with orange, and arranged in a large, pyramidal, leafy panicle. The calyx is deeply cleft into five pointed segments with hairy margins; and the broadly bell-shaped corolla is deeply divided into five wide lobes. All the five stamens are united by their filaments, forming a kind of cup around the ovary. [Illustration: THE COMFREY.] There is another beautiful Loosestrife--the Purple Loosestrife--that is often seen on river-banks; but as it is not particularly partial to this habitat, but rather grows in marshes and wet places generally, it is described in another chapter (XV). It should be noted, however, that the two plants are not so nearly allied as the popular names suggest; for while the one described above is of the Primrose family, the latter is a member of the _Lythraceæ_, and differs in having a corolla of free petals. Passing now to the order _Polygonaceæ_ we have to note the Great Water Dock (_Rumex Hydrolapathum_)--a smooth plant, varying from three to six feet in height, much resembling other Common Docks in general appearance, but found almost always on the borders of streams and ponds. Its leaves are lanceolate in form, usually pointed, and either flat or slightly curled at the margins. The upper ones taper down into the stalk; but the lower ones, which are from one to two feet long, are often heart-shaped at the base. The reddish-green flowers are closely-whorled, and form long panicles. The perianth is cleft into six parts, of which the three outer are smaller and covered with little tubercles, while the inner become enlarged and close over the triangular fruit. Each flower has six stamens and three very short styles. This plant is in flower during July and August.