212 



OUTLINES OF PLANT LIFE. 



size and complexity before being separated from the parent 

 plant. They usually consist of a short axis with a growing 



Fig. 179. — Young plants developing from adventitious buds on leaves of a fern {Asple- 

 niuni bulbiferum\ from which they readily separate to form new plants. A , natural 

 size. £, magnified 2 diam. — After Kerner. 



point and at least rudimentary leaves. They generally arise 

 upon the stem, more rarely from the leaves or the root (fig. 

 179),; Upon the stem they usually 

 take the place of shoots of other forms, 

 developing from axillary buds (figs. 

 180, 182). If formed on leaf or root 

 it is always from adventitious buds. 



Every possible gradation exists, from 

 the simplest to those with well-devel- 

 oped members, constituting a plant of 

 some size. They may be artificially 

 grouped as follows : 



299. (a) Buds. — In these the axis is 

 short and the leaves scale-like. When 

 most highly developed the quantity 

 of reserve food is considerable and the 

 parts of* the bud are often distorted 

 by enlargement to contain the food. The fleshy buds which 



Fig. 180. — Fleshy buds in axils 

 of the leaves of a lily. (Z- 2/2- 

 um bulhiferum). Some- 

 what reduced, — After Van 

 Tieghem. 



