XXVI 



EXPLANATION OF TERMS. 



A Spadix is a fleshy spike, usually enveloped by a leaf-like bract called a 

 Spathe. (Fig. 32.) 



An Ament, or Catkin (FiG. 33), is a scaly sort of spike wherein the 

 flowers are apetalous, — that is, having no corollas. The trees especially 

 bear flowers in aments, they being often composed exclusively of either 

 staminate or pistillate flowers. 



A Head or Capitulum is a short, dense spike that in outline is globular. 



A Corymb differs from a raceme in that its lower pedicels are elongated, 

 thus enabling all the flowers of the cluster to reach about the same height. 

 (Fig. 34.) 



An Umbel is a cluster in which the pedicels branch from the same central 



PETAL 

 PISTIL, 



STAMEN 



CALYX 



OVARY 



Parts 0/ a Flower, 

 FIG. 37. 



Sa Iver-sh aped. 



Ca mpa nulate. 

 FIG. 40. 



point as the ribs of an umbrella. (FiG. 35.) When occurring compound the 

 little clusters are called umbellets. 



A Cyme is a flat-topped flower-cluster, and differs from an umbel in that 

 its innermost flowers are the first to open. (FiG. 36.) 



An Involucre is an arrangement of bracts which subtend or hold a flower 

 or flower-cluster. The thistle family present examples of involucres. 



Staminate Flowers are those possessed of stamens, but which have no 

 pistils, or but rudimentary ones. Pistillate Flowers are just the reverse of 

 those that are staminate. When both of these sorts of flowers are borne on 

 the same plant it is said to be Monoecious, meaning in one household ; 

 when, however, they are borne on different individuals, the plants are called 

 DicEcious, in two households. 



Flowers possessing both of these necessary organs of reproduction, the 

 stamens and pistils, are Perfect ones, and when this is not so they are Im- 

 perfect Flowers. 



