12 THE PLANT. 



not less important function, be compared to the flywheel 

 in an engine, which gives regularity and uniformity to 

 the working. It is in the root that the material is stored 

 up to supply the growing plant with the needful elements 

 for conducting the processes of hfe, according to the 

 requirements made upon it by the action of light and heat. 



All plants which give landscapes their peculiar cha- 

 racter, and clothe the plains and mountain slopes with 

 perennial green, have an underground developement, 

 according to the geological or physical condition of the 

 soil, admirably adapted to their perennial existence and 

 propagation. 



Whilst annuals are propagated and multiplied by seeds 

 alone, and have always a true root easily known by its 

 simphcity of structure, by the absence of buds, and by 

 the comparatively short range of its fibres, the turf and 

 meadow plants are propagated by shoots and runners of 

 a peculiar nature, and in many of them propagation is 

 independent of the formation of seed. 



As the strawberry, which will in a very short time 

 cover extensive tracts of ground, sends forth from the 

 stock above the root-bulb shoots in the shape of run- 

 ners, which creeping along the ground, and producing 

 here and there buds and roots, grow up as independent 

 plants, so the perennial weeds, among which are here 

 included the meadow and pasture plants, spread in a simi- 

 lar manner by corresponding underground organs. The 

 creeping roots of the couch-grass [Triticum repens), the 

 sea lyme-grass [Elymus arenarius), the trefoil (Trifolium 

 pratense), the common toad-flax (Linaria vulgaris)^ pro- 

 pagate their plants by suckers in all directions from the 

 mother-plant. The smooth-stalked meadow-grass [Poa 

 pratensis) is propagated by a mother-stock, consisting of 

 true roots, rooted runners, and creeping suckers; rye 



