EXPLANATION OF TERMS 



THE comprehension of the flower descriptions and of the 

 opening chapters will be facilitated by the reading of the fol- 

 lowing explanation of terms. For words or expressions other 

 than those which are included in this section, the Index of 

 Technical Terms at the end of the book should be consulted. 



The Root of a plant is the part which grows downward into 

 the ground and absorbs nourishment from the soil. True roots 

 bear nothing besides root-branches or rootlets. 



" The Stem is the axis of the plant, the part which bears all 

 the other organs." (Gray.) 



A Rootstock is a creeping stem which grows beneath the 

 surface of the earth. (See Blood -root and Solomon's Seal. Pis. 

 I. and LV.) 



A Tuber is a thickened end of a rootstock, bearing buds, 

 " eyes," on its sides. The common Potato is a familiar ex- 

 ample of a tuber, being a portion of the stem of the potato plant. 



A Corm is a short, thick, fleshy underground stem which 

 sends off roots from its lower face. (See Jack-in-the-Pulpit, 

 PL CLV.) 



A Bulb is an underground stem, the main body of which 

 consists of thickened scales, which are in reality leaves or leaf 

 bases, as in the onion. 



A Simple Stem is one which does not branch. 



A Stemless plant is one which bears no obvious stem, but 

 only leaves and flower-stalks, as in the Common Blue Violet and 

 Liver-leaf (PI. CXXVI.). 



A Scape is the leafless flower-stalk of a stemless plant. (See 

 Liver-leaf, PI. CXXVI.) 



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