58 



TBE STEM 



ulblets ul' the Ti^ei" Lilv. 



as this perhaps represent the first step in the process of 

 cliange by ^yhich tlie ancestors of our Bellwort (Fig. 20) 

 and Bloodroot (Fig. 25) became subterranean in liabit. 



86. Stems for propagation; that is, for tlie establish- 

 ment of new individnal plants. ^lanjr plants reproduce 

 their kind without the intervention of seed. Some part 

 of the original plant is separated from the parent stock 

 and develojjs into a new plant. This is termed vegetative 

 reproduction, to distinguish it from reproduction by seed. 

 The Potato is regularly propagated by this method, as 

 also in the tropics are Sugar Cane, the Banana, and the 

 Pineapiple, none of wliich ordinaril}' produce seed. 



87. A curious mode of vegetative 

 reproduction is by the bulblets, or small 

 bulbs, formed in the axils of the leaves 

 of certain garden Lilies (Fig. 43), and 

 often in the flower clusters of the Onion. 

 They are plainly buds ■with thickened 

 scales. They never grow into branches, 



but detach themselves ■ndien full grown, fall to the ground, and take 



root there to form ne^Y plants. 



88. A stolon is a branch from above ground, vhicli reclines or 

 becomes prosti-ate and strikes root (usually from the nodes) \Yherever 

 it rests on tlie soil. Tlience it may send up a vigorous shoot, wliich 

 has I'Ofits of its o«n, and becomes au 



independent jdantwhen tlie connecting 

 part dies, as it, dues after a while. 



89. An offset is a short stolon, or 

 sucker, with a crown of leaves at the end, 

 as in the Houseleek (Fig. 44), which 

 propagates abundantly in tins way. 



90. A runner, of which the Straw- 

 l)eny presents the most familiar and 

 characteiistic example, is a long and 

 slender, tendril-like stolon, or branch from next the ground, destitute 

 of conspicuous leaves. Kach rininef of tlie Strawberry, after ha\-ing 

 grown to its fidl Inii^tli, strikes iriut fi-om the tip beconnng fixed 

 to the ground, then forms a bud there, which develops into a tuft of 

 leaves, and so gives rise to a new plant, which semis out new runners 

 to act in the same way. In this manner a single Strawberry plant 

 will spread over a large space, or produce a great number of plants, 

 in the course of the summer, all connected at first by the slender 



-^>P^ 



44. 



Houseleek, propagating 

 by offsets. 



