1074 A TEXTBOOK OF THEORETICAL BOTANY 



While terminal inflorescences are progressive structures and show 

 evidences of development, the intercalary types seem rather to have origi- 

 nated by the gathering together and condensation, that is to say reduction, 

 of more extensive branch systems, each with its terminal flower or inflores- 

 cence. Agreeably to our supposition that the primitive terminal flower is a 

 starting point, we may regard terminal inflorescences as being also relatively 

 primitive. 



The fertility of flowers often varies with their position in the inflorescence 

 and those at the base or summit may be quite sterile. Sometimes entire 

 inflorescences may be sterile and transformed for other uses, as in Vttis and 

 Adenia (Passifloraceae), where they become tendrils. 



The curious inflorescences of many tropical trees, which spring directly 

 from the surface of old stems (cauliflory or cladanthy), are peculiar not only 

 in position but sometimes in origin. They are, as a rule, reduced terminal 

 inflorescences on suppressed side-shoots and conform otherwise to the 

 various types recognizable among terminal inflorescences generally, though 

 often in a condensed and obscure pattern. Exceptionally, however, they are 

 adventitious and arise endogenously from a secondary cortical meristem. 



Cauliflory is a term which covers a variety of flowering habits with the 

 common feature that flowers and fruit are borne on old, thickened branches 

 or on the main trunk of a tree. This is in striking contrast to the habit of 

 nearly all trees of temperate zones, whose flowers are borne only on the 

 voung branches. Cauliflory is a widespread character, both in a geographical 

 and a systematic sense, of the trees of tropical forests, but it is notably 

 common only among the trees of the lower stories of the canopy and is 

 seldom found in trees which belong to the highest story. The latter some- 

 times display pendiiliflory, which is a condition in which the flowers are 

 borne on long, thin, pendent shoots, which hang down below the crown. 

 Cauliflory is found in very few trees of temperate climates, the Judas Tree, 

 Cercis siliqiiastrum, being one of these exceptions. 



Cauliflory may be general, which means that flowers may appear any- 

 where, either on the branches or trunk. Ramiflory is a modification, 

 flowers appearing on the older branches but not on the trunk itself. The 

 opposite condition is triinciflory; but neither of these terms is much used. 

 The extreme condition is seen in certain " geocarpic " species of Ftcus, 

 in which the flowering shoots arise only at the base of the main trunk, 

 which appears to be surrounded by bunched masses of fruits, partly lying 

 on the ground, along which the flowering shoots may creep like runners, 

 for distances of several metres. 



Biologically the habit of cauliflory may be valuable in exposing the 

 flowers much more freely than would be the case if they were immersed in 

 the dense canopy of the forest, but we know too little of the floral biology 

 of the tropical forests to be sure whether this is truly a gain or not. In any 

 case there must be some underlying physiological cause, which is at present 

 quite obscure. 



The more types of plants are examined, the more clearly will it be 



