LIFE-HISTORY 41 



terranean shoots : — rhizomes {e.g. Dandelion), tubers {e.g. 

 Potato), bulbs {e.g. Hyacinth), corms {e.g. Crocus) — or in the 

 form of roots. In the following vegetative season these 

 underground parts send up shoots which force their way out 

 of the soil and bear foliage-leaves and flowers. 



Besting Condition of Trees and Shrubs. — In perennial 

 woody plants a considerable part of the sub-aerial shoot 

 persists during winter. The woody stems and the' buds, usually 

 covered with scales, represent the resting tree or shrub. Some 

 of these woody plants shed their foliage-leaves before winter 

 sets in — e.g. Hazel and Larch — and are described as deciduous. 

 Others retain their green leaves during that season, and are 

 termed evergreens — e.g. Pines, Firs, Yew, Ivy, Box, and Heaths. 

 But even the evergreens do not retain the whole of their 

 leaves for an indefinite period : each year the oldest leaves 

 drop off, so that a green leaf lives only for a few years. 



METHODS OF VEGETATIVE MULTIPLICATION. 



Many flowering plants are able to increase in number with- 

 out the intervention of seed-production. Portions of the plant 

 become separated from the mother-plant by the decay of parts 

 which connect them with the latter. These disconnected 

 younger sections, having produced roots of their own, become 

 distinct individuals. For example, the long internodes of the 

 Strawberry-runners may decay and the tufted shoots at the 

 nodes consequently become separate plants. Again, the 

 decay of those parts of the stem which connect the tubers of 

 a Potato with the mother-plant has the same result, for each 

 tuber can produce a new Potato-plant. Frequently in bulbous 

 plants young bulbs arise in the axils of several scales, or a 

 number of little bulbs may appear side by side in the axil of 

 one scale ; in either case, the death of the old bulb leads to 

 separation of the daughter-bulbs. The horizontal lateral roots of 

 the Hazel, Poplar, and Rose, give off erect adventitious shoots — 

 the so-called suckers — which force their way out of the soil and 

 assume the appearance of ordinary shoots. The suckers may 

 become separate individuals by the decay of the connecting 

 root and the production of adventitious roots at the bases of 

 their own stems. "Cuttings," as taken by gardeners, also 

 illustrate the vegetative multiplication of plants. 



