494 PLANTS AND MAN 



Basidium. — The club-shaped spore-bearing structure found in the Hfe 



history of all the club fungi or Basidiomycetes. 

 Bast fiber. — Slightly lignified sclerenchyma cells found in phloem or 



pericycle of some plants. 

 Berry. — A type of fleshy fruit formed from a single pistil; example, 



grape or tomato. 

 Biennial. — Completing the life cycle from seed to seed in two years; 



usually the seed grows into a plant the first year, produces flowers and 



fruit the second year and then dies. Example, beet. 

 Bract. — ^A leaf-like part of a flower sometimes mistaken for a petal; 



conspicuous in such flowers as dogwood. 

 Bran. — The fruit and seed coats (husks) of wheat grains, removed in 



making white flour. 

 Bulb. — The short stem surrounded by fleshy leaf bases which serves as a 



reproductive organ in some plants; example, onion and tulip. 



Caffeine. — A stimulating alkaloid substance found in coff"ee and tea. 

 Calyx. — The whorl of sepals making up the outermost part of a flower; 



usually green. 

 Cambium. — The growing tissue from which new bark and wood arise 



in trees and shrubs. 

 Cankers. — Swellings or tumors produced as the result of bacterial or 



fungus invasion of plant tissues. 

 Carbohydrate. — A compound of carbon, hydrogen and oxygen with the 



latter two in the proportions of 2: 1; example, sugar or starch. 

 Carnivorous. — Flesh-eating. 

 Carotin. — A reddish yellow pigment chemically composed of hydrogen 



and carbon, abundant in carrots. 

 Caryopsis. — ^A type of achene in which the thin dry wall of the fruit 



adheres to the seed coat; example, corn or wheat grain. 

 Catkin. — A wind-pollinated, cone-like reproductive structure consisting 



of an axis bearing small flowers, each lacking petals and sepals; 



example, willow or birch. 

 Cell. — A unit of highly organized protoplasm surrounded by a non- 

 living cell wall. 

 Cellulose. — A complex carbohydrate substance which makes up most 



of the cell wall in plants. 

 Chlorophyll. — The green pigment found in plant cytoplasm, made up 



of carbon, hydrogen, oxygen, nitrogen and magnesium; essential for 



carrying on photosynthesis. 

 Chloroplast. — The cell structure containing chlorophyll, giving green 



plants their characteristic color. 



