144 SITUATION AND POSITION OF LEAVES. 



nature as furnishing food to the brute crea- 

 tion, are subjects foreign to our present pur- 

 pose, and need not here be insisted upon. 

 Their essential importance to the plant which 

 bears them, and the curious functions by 

 which they contribute to its health and in- 

 crease, will presently be detailed at length. 

 We shall first explain their different situa- 

 tions, insertions, forms, and surfaces, w r hich 

 are of the greatest possible use in systemati- 

 cal botany. 



The leaves are wanting in many plants, 

 called for that reason plant a aphyllce^ as 

 Salicornia, Engl. Bot. t. 415 and 1691, 

 Stapelia variegata^ Curt. Mag. t. 26, glan- 

 duliflora, Exot. Bot. t. 71, and all the spe- 

 cies of that genus. In such cases the surface 

 of the stem must perform all their necessary 

 functions. 



1. With respect to Situation and Position, 

 Folia radicalia, radical leaves, are, such as 

 spring from the root, like those of the 

 Cowslip, Engl. Bot. t. 5, and Anemone 

 Pulsatilla, t. 51. 

 Caulinay stem-leaves, grow on the stem 



