68 BOTANY. 



(1) The Stem J branches are only stems which originate 

 laterally upon other stems. 



The other caulome forms are : 



(2) Runners, which are bract-bearing, slender, weak, 

 and trailing. 



(3) Root-stochs, which are bract- or scale-bearing, usually 

 weak, and generally subterranean. 



(4) Tubers, which are bract- or scale-bearing, short and 

 thickened, and subterranean. 



(5) Corms, which are leaf-bearing, short and thickened, 

 and subterranean. 



(6) Bulb-axes, which are leaf-bearing, short and conical, 

 and subterranean. 



(6) Flower-axes, which are bract-, perianth-, stamen-, 

 and pistil-bearing, short and usually conical and aerial. 



(8) Tendrils, which are degraded, slender, aerial cau- 

 lomes, nearly destitute of phyllomes. 



(9) Thorns, which are degraded, thick, conical, aerial 

 caulomes, nearly destitute of phyllomes. 



122. Phyllome. — The phyllome is always a lateral mem- 

 ber upon a caulome. It is usually a flat expansion and ex- 

 tension of some of the tissues of the caulome. Its most 

 common form is 



(1) The Leaf (foliage), which is usually large, broad, 

 and mainly made up of chlorophyll-bearing tissue. 



The other phyllome forms are : 



(2) Bracts, which are smaller than leaves, generally 

 green. 



(3) Scales, which are usually smaller than leaves, want- 

 ing in chlorophyll-bearing tissue, and generally with a firm 

 texture. 



(4) Floral envelopes, which are variously modified, but 



