The Marsh St. John's-wort (_Hypericum Elodes_--order _Hypericaceæ_) is a somewhat shaggy little plant, common in the bogs of many parts of Britain, more especially in West England and Ireland. It varies from a few inches to a foot in length; with prostrate stems rooting at the base; and rounded, opposite leaves without stipules. Both stem and leaves are clothed with white, woolly hairs, the latter on both surfaces. The flowers, which bloom during July and August, are of a pale yellow colour, and form a few-flowered, terminal panicle. They have five small, oval sepals, fringed with little red-stalked glands; five petals, about three times as long as the sepals; and many stamens, united to more than half way up into three bundles. (See Plate V, Fig. 6.) The Blue Marsh Vetchling or Marsh Pea (_Lathyrus palustris_--order _Leguminosæ_) is occasionally to be met with in boggy places, flowering from June to August. It is a smooth plant, with a weak, winged stem, two or three feet long; and pinnate leaves consisting of from two to four pairs of narrow, sharp leaflets, and terminating in a branched tendril. At the base of each leafstalk are two narrow, half arrow-shaped stipules. The flowers are of a bluish purple colour, and are arranged in one-sided racemes, of from two to six flowers on long stalks. The pods are smooth and about an inch in length. This plant is represented on Plate V, Fig. 5. [Illustration: THE PURPLE LOOSESTRIFE.] Some of the Willow-herbs (_Onagraceæ_) are very partial to wet and boggy places. A few species of other habitats are described in Chapters X and XI, and these, together with the members that come within the range of the present chapter, are readily distinguished by their willow-like leaves and the very long inferior ovaries of their flowers. We shall here note three species-- 1. The Great Hairy Willow-herb or Codlins and Cream (_Epilobium hirsutum_).--A large, erect, hairy plant, from three to six feet high, with numerous underground suckers, and a stout, round, branched stem. Its leaves are opposite, sessile, often clasping the stem, narrow, and finely toothed. The flowers are nearly an inch in diameter, of a deep rose colour, arranged in terminal, leafy racemes. They have four broad, notched, spreading petals; eight erect stamens; and a four-lobed stigma. The plant is common in wet places, and flowers during July and August. 2. The Narrow-leaved or Marsh Willow-herb (_E. palustre_).--A smaller plant, seldom exceeding eighteen inches in height, frequent in bogs and marshes, flowering during June and July. Its stem is round, with two lines of downy hairs on opposite sides; and its leaves are sessile, opposite, very narrow, tapering towards the base, and sometimes slightly toothed. The flowers are small, pink, nodding when in bud, arranged in a terminal raceme. Both flowers and fruit resemble those of the last species except that the stigmas of the former are not divided.