1. The Water-cress (_Nasturtium officinale_).--A succulent plant, with a branched stem rooting at the base, growing freely in ditches, shallow streams and muddy places, and flowering from May or June to the end of the summer. Its leaves are pinnately divided into from seven to eleven wavy or slightly-toothed segments, the terminal one of which is usually larger than the others and nearly round. The flowers are small, white, in short, crowded racemes; and the pods are spreading, more than half an inch long. [Illustration: _Plate V._ FLOWERS OF BOGS AND MARSHES. 1. Marsh Gentian. 2. Marsh Marigold. 3. Marsh Orchis. 4. Marsh Mallow. 5. Marsh Vetchling. 6. The Marsh St. John's-wort. 7. Bog Pimpernel.] [Illustration: THE LESSER SPEARWORT.] 2. The Marsh Yellow Cress (_N. palustre_), common in muddy places.--A slender plant with a fibrous root, and pinnate leaves with irregularly-toothed segments which are smaller towards the base. The flowers are yellow, about an eighth of an inch in diameter, with petals no longer than the sepals. They bloom from June to September. The pods are oblong, swollen, slightly curved, a quarter of an inch long. 3. The Amphibious Yellow Cress (_N. amphibium_).--An erect plant, two or three feet high, with fibrous root and creeping runners, flowering from June to September, moderately common on the banks of muddy streams. Its leaves are narrow-oblong, three or four inches long, deeply toothed, or cut into narrow lobes; and the flowers are yellow, similar to those of the other species, and similarly arranged, but with petals twice as long as the sepals. The pods are broad, only about a sixth of an inch long, with a rather long style. In the marshes of the South of England we may often see the Marsh Mallow (_Malva officinalis_ or _Althæa officinalis_), of the order _Malvaceæ_, flowering during August and September. Its stem is hairy, with erect flowering branches two or three feet high; and the leaves are shortly stalked, thick, velvety, broadly ovate, and sometimes divided into three or five lobes. The flowers are shortly stalked in the axils of the upper leaves, or sometimes collected into a terminal raceme. Round each one is a whorl of several narrow bracts, shorter than the calyx, and united at their bases. The calyx is five-lobed; and the corolla consists of five broad, rose-coloured petals. This plant is shown on Plate V, Fig. 4. [Illustration: THE GREAT HAIRY WILLOW-HERB.]