TYPES OF STEMS. 369 



nut, apple, etc. The trees are usual]}' deciduous, i.e., cast their 

 leaves with the approach of wuitcr. The main axis is some- 

 times maintained, but more often disappears (trunk is deliques- 

 cent), because of the large branches which maintain an ascending 

 direction, and thus lessen the importance of the central axis 

 which is so marked in the cone type. Trees of this type, and in 

 fact all deciduous trees, exhibit their character or habit to better 

 advantage during the winter season when they are bare. Trees 

 of this type are not so well adapted to conditions in the higher 

 altitudes and latitudes as the cone type, for the reason given in 

 the discussion of that type. The deciduous habit of the oaks, 

 etc., enables them to withstand heavy winds far better than if 

 they retained their foliage through the winter, even were the 

 foliage of the needle kind and adapted to endure cold. 



718. The deliquescent type. — The elm is a good illustration 

 of this tj'pe. The main axes and the branches fork by a false 

 dichotomy, so that a trunk is not developed except in the forest. 

 The branches rise at a narrow angle, and high above diverge 

 in the form of an arch. The chief fohage development is lofty 

 and spreading. 



Trees possess several advantages over vegetation less lofty. 

 They may start their growth later, but in the end they outgrow 

 the other kinds, shade the ground and drive out the sun-loving 

 kinds. 



II. Creeping, Climbing, and Floating Stems. 



719. Prostrate type. — This type is illustrated by creeping or 

 procumbent stems, as the strawberrv', 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 curcubits like the squash, pumpkin, melons, etc. These 

 often cover extensive areas by branching and reaching out radi- 

 allv on the ground or climbing over low objects. The cucurbits 

 should perhaps be classed with the climbers, since they are capa- 

 ble of chmbing where there are objects for support, but they 

 are prostrate when grown in the field or where there are no ob- 



