LESSON 6.] SUBTERRANEAN FORMS : ROOTSTOCKS. 41 



always perennials (41) ; the subterranean shoots live over the first 

 winter, if not longer, and are provided with vigorous buds at every 

 joint. Some of these buds grow in spring into upright stems, bearing 

 foliage, to elaborate the plant's crude food into nourishment, and at 

 length produce blossoms for reproduction by seed ; while many oth- 

 ers, fed by nourishment supplied from above, form a new generation 

 of subterranean shoots ; and this is repeated over and over in the 

 course of the season or in succeeding years. Meanwhile as the sub^ 

 terranean shoots increase in number, the older ones, connecting the 

 series of generations into one body, die off year by year, liberating 

 the already rooted side-branches as so many separate plants ; and 

 so on indefinitely. Cutting these running rootstocks into pieces, 

 therefore, by the hoe or the plough, far from destroying the plant, 

 only accelerates the propagation ; it converts one many-branched 

 plant into a great number of separate individuals. Even if you 

 divide the shoots into as many pieces as there are joints of stem, 

 each piece (Fig. Go) is already a plantlet, with its roots and with a 

 bud in the axil of its scale-like leaf (either latent or apparent), and 



having prepared nourishment enough in the bit of ,, 



stem to develop this bud into a leafy stem ; and so 

 a single plant is all the more speedily converted 

 into a multitude. Such plants as the Quick- 

 grass accordingly realize the fable of the Hy- 

 dra ; as fast as one of its many branches is cut 65 

 off, twice as many, or more, spring up in its stead. Whereas, when 

 the subterranean parts are only roots, cutting away the stem com- 

 pletely destroys the plant, except in the rather rare cases where the 

 root produces adventitious buds (58). 



99. The more nourishment rootstocks contain, the more readily do 

 separate portions, furnished with buds, become independent plants. 

 It is to such underground stems, thickened with a large amount of 

 starch, or some similar nourishing matter stored up in their tissue, 

 that the name of rhizoma or rootstock is commonly applied ; such, 

 for example, as those of the Sweet Flag or Calamus, of Ginger, of Iris 

 or Flower-de-luce (Fig. 133), and of the Solomon's Seal (Fig. 66). 



100. The rootstocks of the common sorts of Iris of the gardens 

 usually lie on the surface of the ground, partly uncovered ; and 

 they bear real leaves (Fig. 133), which closely overlap each other; 



F'l. 65. A piece of the running rootstock of the Peppermint, with its node or joint, and 

 an axillary bud ready to grow. 



J,* 



