OEGANS OF NIJTfilTION. 



107 



2. Subterranean Modifications of Steins. — All these modifica- 

 tions of stems were formerly confounded with roots, and they 



Fig. 208. 



Fig. 209. 



i Fig- 208. A portion of the rhizome of a species of Iris. Fig. 209. A por- 



/ tion of the rhizome of the Solomon's Seal i^Polygojiatum muUifionim). 



I b. A branch, b'. Bud. c, c. Scars produced by the decay of old branches. 



/ r, r. Roots. 



are still in common language thus designated. They are dis- 

 tinguished, however, from roots, either by the presence of leaves 

 and buds, or by scales or modified leaves, or by the presence of 

 scars on their surface produced by the falling off of former 

 leaves or buds. The different forms of aerial stems described 

 above, when partially subterranean, may be also distinguished 

 in a similar manner from roots. 



a. The Creeping Stem. (Fig. 210.)— This form of stem is 

 sometimes called a Sobolcs, and in common language a creeping- 

 Fig. 210. 



Fig. 210. Creeping stem of the Sand Carex (Carex arenaria). 1. Terminal 

 bud by which the stem continues to elongate. 2, 3, 4. Shoots produced 

 from former buds. 



