CHAPTER II. THE STEM. 



13 



Fig. 16. — Voluble or twining 

 stem of the Morning-glory. 



Kinds of Above-ground Stems as Regards Habits of 

 Growth. Among the more important of these are the following : 



The twining or voluble stem is one 

 which twists or coils about a support, as 

 the stem of the Morning-glory, Fig. 16, 

 and that of the Hop. 



The scandent or climbing stem is one 

 that rises by attaching itself, by means 

 of special organs modified for the 

 purpose, to some extraneous support. 

 There are various modes of climbing. 

 The Tropeolum and Solanum jasmin- 

 oides, for example, climb by means of 

 sensitive petioles, Fig. 18 ; the Ivy, and 

 Poison Rhus by means of rootlets ; the 

 Grape and Ampelopsis Veitchii, by 

 means of tendrils, Fig. 17, and some 

 species of the Rose and Bramble climb 

 in a rude way by means of hooked 

 prickles. Tendrils also may be either 

 modified branches, as in the Grape ; 

 modified leaflets, as in 

 the Pea, or modified 

 stipules, as in the Sar- 

 saparilla. 



The Culm is the 

 peculiar jointed stem 

 of the Grasses and 

 Sedges. It may be 

 herbaceous, as in 

 Wheat and Rye, or 

 woody, as in the Cane 

 and Bamboo. 



The scape is a flowering stem desti- 

 tute of true foliage leaves, as those of 

 the Dodecatheon and Dandelion. 



The Caudex is such a scaly un- 

 branching stem as we observe in Palms and Tree Ferns. 



The Stolon is a prostrate or declined branch, the end of 



Fig. 18. — Portion 

 of stem of Solanum 

 jasminoides, a leaf- 

 climber. 



Fig. 17. — Portion of the stem of 

 Ampelopsis Veitchii, showing 

 branching tendril, provided with 

 terminal sucker-like discs. 



