ROOT AND SUBTERRANEAN STEM. 



77 



short it seems a part of the root, 

 the leaves spring are called 

 Nodes (L. nodus, knot) ; the 

 spaces between the nodes are 

 Internodes (Fig. 93). The buds 

 are usually in the aadl of the 

 leaf; that is, at the base of the 

 leaf or leaf-stalk, at its upper 

 face. There is a bud also at 

 the apex of the stem ; this is 

 the Terminal bud; the other 

 buds are Axillary, or Lateral. 



150. Steins are Subteiranean 

 (L. sub, under, terra, earth) and 

 Superterranean (L. super, 

 above). Subterranean stems 

 include the Bulb, Corm, Rhi- 

 zome, Tuber. 



The points from which 



Via. 93.— Flax Dodder (CSucu/aBpai- 

 num) on clover ; fls. clustered. 



151. The Bulb is a suppressed sub- 

 terranean stem, with many nodes, 

 bearing fleshy leaves in the form of scales or of coats. The Lily bulb 

 is Scaly. The Onion (Fig. 94) is Tunicated, or Coated (L. tunica, coat) ; 

 the central part representing the stem is hemispherical. Each scale 

 of the Lily, or tunic (coat) of the Onion, may 

 pi-oduce a bud or a bulb in its axil. 



152. The Corm is bulb-like, with many nodes, 

 but few scales, and these quite small, as in the 

 Cyclamen (Pig. 245). 



153. The Rhizom.e, or Root-stock, is usually 

 fleshy, and always developed in length ; it may 

 be prostrate, erect, or 

 creeping. It has 

 many nodes and 

 scales, usually smaller 

 than those of the 

 corm. When abrupt 

 at the lower end it 

 is called Prcernorse, or 

 Bitten, as in Solo- 

 mon 's-Seal and Cala- 

 mus-Plag. The Ehi- 



zome of the Common Ginger (Pig. 151) furnishes the ginger of com- 

 merce. 



154. The Tuber is solid, fleshy, with many nodes ; but the scales 

 are so small that the naked bud looks like and is called an Eye. The 

 Jerusalem Artichoke (Pig. 95) and Irish Potato are examples. 



7* 



Fig. 94. — Vertical sec- 

 tion of Onion (AUium 

 cepct) : ij suppressed subt. 

 stem. 



Fig. 95. — Jenisalem Artichoke 

 {HelianthuB tvbei-osm). 



