This section is from the book "Wayside And Woodland Blossoms", by Edward Step. Also available from Amazon: Wayside And Woodland Blossoms: A Guide To British Wild-Flowers.
The Sundews, of which we have three native species, must be sought out, for they seldom obtrude themselves on the attention of those whose eyes have not been trained to see them. They must be looked for in peat bogs, and in hollows on sandy heaths, where they grow in crowds. The leaves of D. rotundifolia arise from a slender rootstock, and lie on the ground in the form of a rosette, from the centre of which the tall slender flower-stalks appear in July and August. Each leaf bears near the upper margins several rows of long crimson glands, terminating in rounded heads, and reminding one of a sea-anemone's tentacles; indeed, they serve a similar purpose. These glands secrete a clear sticky fluid, which serves to detain small insects that crawl over the leaf. Their efforts to free themselves irritate the glands, which all bend over to the insect; at the same time the margins of the leaf-blade begin to become incurved, and the insect is effectually secured in the hollow, ultimately being digested and the soft parts assimilated by the plant. Readers desiring to learn more of these curious habits of the plant are advised to grow it in a saucer of peat, and to read Mr. Darwin's celebrated work on "Insectivorous Plants."
The leaf in this species, as its name signifies, has a round blade, and this is attached to a long hairy leaf-stalk. In the Narrow-leaved Sundew (D. intermedia) the blade is spoon-shaped, and merges insensibly into the smooth leaf-stalk. In the third species, or Long-leaved Sundew (D. anglica) the entire leaf is similar to that of intermedia, but twice the length. In neither of the long-leaved species are the leaves laid flat as in rotundifolia; those of intermedia are erect, whilst those of anglica are borne half-erect. D. anglica is rare in the South of England ; the others are well distributed. The name is derived from the Greek, Drosera, dewy, in allusion to the bedewed appearance of the leaves.
Round leaved Sundew.
Drosera rotundifolia. - Droseraceae. The mericarps in Fennel are half-round, and marked on the outside with five ridges, which mark the lines of union of the sepals (which are adherent to the carpels) and the central keels of the sepals. Between these ridges are tubes (vittae) containing essential-oil, and it is to their presence that fruits of this order owe their aromatic qualities.