48 



Lecture 11, (July 2b, 1900. 



1. Erect Stems. 2. Lianas.. 



'.■**.f ' 



Tlie philosophy of stems, is really the philosophy of Ecology. The 

 stem largely decides the character of the plant. All clirahing plants 

 are called leaves. Great, vawiety of mean^ of climbing ; tendrils, 

 roots, thorns, petioles, stems, etc. 



Lianas most developed in rich tropical forests, also found in 

 our own region growing upon trees. Warming and Kerner regard the 

 liana as a unique and economical method of getting at the light. 

 Large expanse of foliage with. little mechanical support. As forms 

 become independent they'have greater difficulty in living ; hence 

 the liana has not so sood a chance as the tree upon which it grows. 

 Chief danger is death of the host plant, also the liana may be torn 

 away by the wind. Stems show compensation. 



3. Epix>hvtes . 



Atterapt to meet same conditions as the lianas. Here we have few,. 

 except lichens. In Florida there is the long moss. Another theory 

 is that it is the result of a struggle for life in a crowded forests 

 Mere existence is only possible when away from the crowded ground. 



4. Creeping stiam . 



Example of two types— clover and raspberry. First creeps along the 

 ground and roots at the nodes. The second has a walkiiig habit, as 

 has also the camtosoris r&izophyllium. Great meaning of this form 

 of stem is reproduction ; to increase the area of the plant. 

 Vegetative reproduction. Also the migration to a new field where food 



