KINDS OF STEMS AND BRANCHES. 37 



§ 2. Of Stems. 



90. Forms or Kinds of Stems. Differences in the size and consistence of stems, 

 such {IS distinguish plants into herhs, shrubs, and trees, have already been noticed, 

 in paragraphs G4, Go, and G6. A stem is 



Herbaceous, when it belongs to an herb, that is, has very little wood in its com- 

 position, and does not live over winter above ground : 



SJirubby, when it belongs to a shrub, or is woody : 



Arboreous or Arborescent, when the plant is a tree, or like a tree ; that is, when 

 it is tall and grows by a single trunk. 



91. Tlie peculiar straw-stem of a grass or grain is named a Culm. It is gen- 

 erally hollow, except at the joints, which are hard and sohd ; but in Indian Corn, 

 Sugar-Cane, and some other Grasses, it is not at all hollow. 



92. As to the mode of growth or the direction it takes in growing, the stem is 

 Erect or UprigJit, when it grows directly upwards, or nearly so : 

 Ascenamg, when it rises upwards at first in a slanting direction : 



Declined or Reciined, when turned or bent over to one side : 



Decumbent, when the lower part reclines on the ground, as if too wetik to stand, 

 but the end turns upwards more or less : 



Procumbent or Trailing, when the whole stem trails along the ground : 



Prostrate, when it naturally lies flat on the ground : 



Creeping or Runninrf, when a trailing or prostrate stem strikes root along it,s 

 lower side, where it rests on the ground : 



Climbing, where it rises by laying hold of other objects for support ; either by 

 tendrils, as in the Pea, Gourd, and Grape-Vine ; or by twisting its leafstalks around 

 the supporting body, as in the Virgin's Bower ; or by rootlets actmg as holdfasts, as 

 in the Ivy and Trumpet-Creeper (8G) : 



Twining, wlien stems rise by coiling themselves si^irally around any support, as 

 in the Morning-Glory (Fig. 4), Hop, and Bean. 



93. Several sorts of branches are different enough from the common to have 

 particular names. Indeed, some are so different, that they would not be taken for 

 branches without considerable study. Such, for instance, as 



94. Thorns or Spines. Most of these are imperfect, leafless, hardened, stunted 

 branches, tapering to a point. That they are branches is evident in the Ilawthoi'n 

 and similar trees, from their arising from the axil of leaves, as branches do. And 

 on Pear-trees and Plum-trees many shoots may be found which begin as a leafy 



