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113. One of the most striking among the many forms of leaves that go to make up the vegetation of the sluggish stream or the canal is the aptly-named plant here figured.

It is a perennial, the leaves are radical, and from the base of the plant runners are thrown out, each ultimately terminating in a globose tuber. The leaves are typical of what botanists describe as a "sagittate" leaf, and their long stalks are three-edged. The stem is leafless, but bears a number of flowers in series of threes. These flowers are of two kinds, staminate and pistillate, and because, like those of Poterium, they are borne upon the same plant, botanists describe Sagittaria as monœcious, just as they describe the Hop as diœcious, because its two sexes are on different plants. There are three sepals, and three large white petals with purplish spots at their base. The lower flowers contain carpels only, which are many in number, and which develop into a compact head of nut-like fruits. The stalks of these pistillate flowers are shorter than those of the staminate flowers above them, which contain purple anthers. It flowers from July to September, and is frequent in England as far north as Cumberland, as an indigenous plant; in Scotland it has become naturalized, and in Ireland it is of local occurrence. It is the only British species.

The name is from the Latin sagitta, an arrow.