54 NOMENCLATURE OF THE LEAF. 



b. Involute in which each lateral margin of the leaf is rolled in- 

 wards ; as in the yellow water-lily, in honey-suckles, and violets. 

 (F.43,a.) 



c. Revolute in which the lateral margins are rolled outwards, as 

 in rosemary, and the primrose tribe. (F. 43, b.) 



d. Circinal in which the leaf is rolled from the apex to the base, 

 as in the ferns. (F. 45.) 



e. Reclinate in which the leaf bangs down and is wrapt round 

 the foot-stalk, as in the buds of the officinal wolf's-bane and the ge- 

 nus anemone. (F. 47.) 



6. In all the varieties of foliation, as the buds open, 

 the leaves gradually unfold themselves, and assume their 

 natural forms. 



The opening of the bud does not, in erery instance, immediately 

 set free the leaves ; for, in some gems, each leaf is separately en- 

 closed in a membranous cover, which opens either laterally or at the 

 apex, and permits the leaf to expand. 



7. After leaves have undergone the process of 

 foliation, and attained their peculiar character, they 

 are said to be either sessile or petiolate, simple or 

 compound. 



8. In describing different species of plants, a know- 

 ledge of the peculiarities attending leaves, is of con- 

 siderable importance ; botanists have therefore been 

 called upon to distinguish them according to their 

 situation, direction, distribution, duration, and other 

 attending circumstances. 



9. Situation .-From their place of situation, they arc 

 called radical, caulinar, rameal, seminal, or floral. 



