444 TEXTBOOK OF BOTANY 



Cambium. A layer between bast and wood by the division of whose 



cells the stem or root grows in thickness. 

 Carbohydrate. A substance composed of carbon, hydrogen, and oxygen, 



and belonging to the class which includes starch and the sugars. 

 Carpel. One of the parts of a compound pistil ; a macrospore leaf. 

 Carpellate. Referring to a cone which bears carpels (macrospore 



leaves). Also used in the same sense as pistillate. 

 Catkin. A more or less dense, scaly flower cluster like that of the poplar, 



alder, or willow. 

 Cell. A unit of living matter. A plant or an animal may be a single 



cell, or may be composed of several or many cells. 

 Chlorophyl. The green coloring matter found in the cells of many plants. 

 Chloroplast. A small chlorophyl-containing body found in the cells of 



green plants. 

 Conjugation. The union of like gametes, such as those of Spirogyra or 



of the bread mold. 

 Cork. A substance (also called suberin) which permeates the walls of 



certain cells, especially of those formed from the cork cambium ; 



the term cork is also applied to the cells themselves whose walls 



contain suberin. 

 Conn. A solid bulb-like structure not covered by thick leaves. 

 Cortex. The part of the stem lying between the epidermis and the 



region in which the vascular bundles are contained. 

 Corymb. A flat-topped or convex flower cluster whose outermost 



flowers are the oldest. 

 Cotyledon. A seed leaf. 

 Cross-pollination. The falling or depositing of pollen from the anther 



of one flower upon the stigma of another flower. 

 Cutin. A secreted waxy layer on the outer surface of the epidermis, 



especially of leaves or fruits. 

 Cutting. A severed portion of a plant from which a whole new plant 



may be developed. 

 Cyme. A flat- topped or convex flower cluster in which the central 



flower is the first to open. 

 Cytoplasm. All the substance of a cell contained within the cell wall, 



except the nucleus. 



Digest. To change an insoluble substance into a form in which it 

 may be dissolved. 



Egg. A female gamete. 



Embryo. The young resting plant contained in a seed. 



