LEAF.- Petiolate, exstipulate, palmate - veined, serrate, base cordate, 5-lobed, terminal lobe acuminate, leaf broader than long. CREEPING stems lie along or below the surface of the ground, and send down roots from their nodes. TRAILING stems are weak, and lie loosely along the ground. Fig. 140. ASCENDING stems stand slanting. Fig. 141. FIG. 142. FIG. 143. Climbing. Twining. CLIMBING stems are weak, and cling by tendrils to the objects about them. TWINING Stems are too weak to stand alone, and support themselves by winding around other stems. LEAF.- Simple, petiolate, exstipulate, featherveined, entire, cordate, sub-acuminate. EXERCISE XXVII. Color, Surface, Size, Structure. COLOR.-Stems may be spotted, striped, green, brown, red, or purple. SURFACE. The surface of stems, like that of leaves, is smooth, rough, shiny, dull, hairy, and glabrous. SIZE.-Stems may be high or low, slender or thick, and it is easy to determine these points. STRUCTURE.-To find out the structure of a stem, you must break it, and observe first whether it is hollow or solid. Next examine it to ascertain if it have any tenacious threads; these are woody fibres, and, when present, they help to make the stem hard |