DICHOTOMOUS BRANCHING. 103 



one side, or on alternate sides of the stem, as shown in 

 Figs. 132 and 133. These forms are, of course, sympodiai. 



146. A comparison of Figs. 127 and 131 will show 

 that there is a superficial resemblance between the forms. 

 On this account the forked cyme is sometimes referred to 

 as a dichasium or false dichotomy. 



147. Dichotomous branching is rare, but occurs in the 

 roots of Club-Mosses, and in Lichens. In the phanero- 

 gams, monopodial branching is the almost invariable rule. 

 The flowering stems, which afford the best illustrations, 

 will be referred to hereafter. 



148. If you examine a few stems of plants at random, 

 you will probably find some of them quite soft and easily 

 compressible, while others will be firm and will resist 

 compression. The stem of a Beech or a Currant is an 

 instance of the latter kind, and any weed will serve to 

 illustrate the former. The Beech and the Currant have 

 woody stems, while the weeds are herbaceous. Between 

 the Beech and the Currant the chief difference is in size. 

 The Beech is a tree, the Currant a shrub. But you are 

 not to suppose that there is a hard and fast line between 

 shrubs and trees, or between herbs and shrubs. A series 

 of plants could be constructed, commencing with an 

 unquestionable herb and ending with an unquestionable 

 tree, but embracing plants exhibiting such a gradual 

 transition from herbs to shrubs and from shrubs to trees, 

 that you could not say at what precise point in the series 

 the changes occurred. 



149. The forms assumed by stems above ground are 

 numerous, and they are described mostly by terms in 

 common use. For instance, if a stem is weak and trails 



