GLOSSARY OF BOTANICAL TERMS 309 



Biennial, a plant which requires two years to complete its life- 

 history. In the second year it produces flowers and fruit, 



and then dies. 

 Bisexual = Hermaphrodite (q.v.). 

 Bract, the leaf or modified leaf on the axis of an inflorescence, 



in the axil of which the flower arises. (The bracts are 



often entirely suppressed, as in the Crucifer family.) 

 Bracteole, the leaf, or one of the leaves, borne on the axis of 



the flower itself, above the bract and below the flower. 



(Bracteoles are often entirely absent) (p. 225). 

 Bud, a short stem axis, crowded with overlapping, young, 



undeveloped leaves, arising close to one another. 

 Bulb, a modified stem, often subterranean and disc-like in form, 



bearing a number of succulent leaves, containing reserve 



materials — e.g., an Onion or a Lily bulb. 

 Bulbil, a deciduous bud, capable of reproducing the species, and 



often containing reserve materials (p. 156). 

 Caleicole, applied to plants which flourish best on calcareous 



(limestone) soils (p. 117). 

 Calcifuge, applied to plants which will not grow on calcareous 



(limestone) soils (p. 117). 

 Calyx, the sepals of a flower considered as a whole ; the outer 



series of a differentiated floral envelope (generally green). 

 CapituJum, or Head, a type of inflorescence in which aU the 



flowers are stalkless, and arranged on a terminal expansion 



of the axis — e.g., the inflorescence of the Compositae. 

 Capsule, a many-seeded dry fruit, composed of two or more 



carpels, which open in various ways to allow the seeds to 



escape (p. 88). 

 Carpel, the modified leaf, bearing and enclosing the ovules. 



The pistil consists of one or several carpels, which may 



be free or united together. 

 Catkin, a close spike of unisexual apetalous flowers, which may 



be shed as a whole — e.g., Willow Catkins (p. 189). 



