ORGANS OF GROWTH. 



17 



Their axis of growth in its simplest state consists of a bud 

 furnished with roots, which multiplies itself by side buds 

 (offsets), forming what is generally called the crown or 

 root-stock. The increase is slow and compact, as in the 

 pseony, Oriental poppy, marshmallow, sea-kale, and rhu- 

 barb ; or it produces short, or long slender runners, called 

 running-roots, furnished with leaf buds which become 

 perfect plants, for which reason they may more properly 

 be considered underground stems (sarmenta), this 

 term being applicable to all plants that increase their 

 domain by running-roots, such as goutweed, mint, dogs- 

 bane, nettle, Michaelmas daisy, sarsaparilla, brake 

 fern, and all such like usurpers. The strawberry and 

 window saxifrage are examples of above-ground sar- 

 menta. The runner of the potato is also of the same 

 nature, but instead of the buds growing into leafy stems 

 they become swollen, round, or oblong fleshy tuberous 

 bodies, which ultimately lose their attachment to the 

 stem, and become independent tubers furnished with 

 buds (eyes), which develop into leafy flower stems, each 

 becoming a separate plant, the tuber ultimately decaying. 

 From this it may be considered a metamorphosed stem, 

 and all such are known by the name of tubers. The 

 Jerusalem artichoke and ulluco of Peru are of the same 

 nature, as also some other knot-rooted plants of the pea, 

 mint, and umbel families. 



In Achimenes and others of the Gloxinia family, also 

 some figworts, the root stems consist of numerous, 

 generally compact scales, forming oblong, linear, or long 

 slender worm -like bodies, growing on, but more usually 

 under the surface ; each scale is a rudimentary bud which 

 in season developes into leaf and flower stems. To this 

 the term lejpicorm is applied. 



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