The other is the Greater Spearwort (R. Lingua), a much larger species, varying from two to four feet in height, and flowering during the same months. It has stout, hollow, erect stems which throw off whorls of root fibres from the lowest joints; and the glossy, yellow flowers vary from one to one and a half inches in diameter. This species is not nearly so common as the other, but occurs more or less in most parts of Britain.

Taking next the cruciferous plants (Cruciferæ), we have first to note a few species of the Nasturtium genus, including the Water-cress and the Yellow-cress. These are all smooth plants, with small yellow or white flowers. They may be distinguished from other crucifers by their loose calyx; simple, rounded stigma on a very short style; and their oblong or narrow pods with the seeds arranged in two rows on each side of the membranous partition. The species with which we are at present concerned are:—

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.

Plate V.

FLOWERS OF BOGS AND MARSHES.

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.