The New Student's Reference Work/Carnivorous Plants

From Wikisource
Jump to navigation Jump to search

Carniv'orous Plants, certain seed-plants which have developed the habit of capturing insects and using them for food. They live usually in swampy regions, and are able to capture insects in various ways, and then digest them and absorb the nutritious substances. The commoner forms are as follows: The pitcher plants, belonging to the genus Sarracenia, are common in swampy ground both north and south. The leaves are shaped like slender hollow cones and rise in tufts from the ground, the cone containing water, and its mouth being more or less overarched by a hood. A sweetish substance is secreted about the rim, and attracts the insects, which fall into the cone and are drowned. Such pitchers are often found more or less filled with the decaying remains of captured insects. In California a huge pitcher plant, Darlingtonia by name, has leaves sometimes three feet high. The best known tropical forms belong to the genus Nepenthes and its allies, in which the urns swing from the tendrils developed at the ends of the leaves. Various forms of Nepenthes are common in greenhouses. Another group of carnivorous plants is the group of sundews, belonging to the genus Drosera. They also grow in swampy ground and have rosettes of basal leaves, which are beset by sensitive glandular hairs. Small insects coming in contact with a sticky gland are held fast, and the leaf closes over the struggling victim and digests it. Perhaps the most remarkable carnivorous plant is Dionæa or Venus' fly-trap, which is found only in sandy savannas near Wilmington, N. C. The leaf blade is constructed like a steel trap, and the two halves snap together whenever any of the bristles are touched by an insect. In this way the insect is caught and gradually digested.

John M. Coulter