=719. Prostrate type.=—This type is illustrated by creeping or procumbent stems, as the strawberry, certain roses, of which a good type is one of the Japanese roses (Rosa wichuriana), which creeps very close to the ground, some of the raspberries, the cucurbits like the squash, pumpkin, melons, etc. These often cover extensive areas by branching and reaching out radially on the ground or climbing over low objects. The cucurbits should perhaps be classed with the climbers, since they are capable of climbing where there are objects for support, but they are prostrate when grown in the field or where there are no objects high enough to climb upon. In the prostrate type, there is economy in stem building. The plants depend on the ground for support, and it is not necessary to build strong, woody trunks for the display of the foliage which would be necessary in the case of an erect plant with a foliage area as great as some of the prostrate stems. This gain is offset, at least to a great extent, by the loss in ability to display a great amount of foliage, which can be done only on the upper side of the stem. [Illustration: Fig. 424. Prostrate type of the water fern (_marsilia_).] Other advantages gained by the prostrate stems are protection from wind, from cold in the more rigorous climates, and some propagate themselves by taking root here and there, as in certain roses, the strawberry plant, etc. Some plants have erect stems, and then send out runners below which take root and aid the plant in spreading and multiplying its numbers. =720. The decumbent type.=—In this type the stem is first erect, but later bends down in the form of an arch, and strikes root where the tip touches the ground. Some of the raspberries and blackberries are of this type. =721. The climbing type.=—The grapes, clematis, some roses, the ivies, trumpet-creeper, the climbing bittersweet, etc., are climbing stems. Like the prostrate type, the climbers economize in the material for stem building. They climb over shrubs, up the trunks of trees and often reach to a great height and acquire the power of displaying a great amount of foliage by sending branches out on the limbs of the trees, sometimes developing an amount of foliage sufficient to cover and nearly smother the foliage of large trees; while the main stem of the vine may be not over two inches in diameter and the trunk of the supporting tree may be three feet in diameter.