Glossary. 217 



Chlorophyl. The green coloring matter of plants. 



Cion. See Scion. 



Cleft-graft. A sort of grafting in which the scion is cut 



wedge-shaped at the lower extremity, and is then inserted 



in. a cleft in the end of a trunk or branch which has been 



severed. 

 Close fertilization. The action of pollen upon the pistil 



of the same flower ; self-fertilization. 

 Cold-frame. A frame covered with glass, cloth, or paper, 



without bottom heat, used for starting plants early in 



spring, for receiving plants transplanted from a hot-bed or 



forcing-house, or for protecting plants during the winter. 

 Conservatory. A glass house for preserving or growing 



tender plants. Popularly, the term is applied to houses 



in which plants are grown for display of flowers. 

 Corolla. The inner envelope of the flower. The parts, 



when distinct, are called petals. 

 Corm. A solid bulb-like tuber, as in the gladiolus and 



crocus ; bulbo-tuber. 

 Corymb. A flower cluster which is flat or convex on 



top and in which the outer flowers bloom first. 

 Cotyledon. A small leaf borne in the seed ; seed-leaf. 



In many plants the cotyledons rise to the surface, when 



the seed germinates, and increase in size. 

 Cross. The offspring of any two flowers which have 



been cross-fertilized. 

 Cross-breed. A cross between varieties of the same species ; 



half-breed, mongrel, variety-hybrid. 

 Cross-fertilization. The action of pollen upon the pistil 



of another flower of the same species. Cross-fertilization 



is commonly used to denote the mere conveyance of pollen 



pollination but better usage confines the term to the action 



of pollen upon the pistil. 

 Cross-pollination. The conveyance of the pollen to the 



stigma of another flower. 



