ORGANS OF NUTRITION. 



177 



Stipules either remain attached as long as the leaf, when they 

 are said to be persistent; or they fall otF soon after its expansion, 

 in which case they are deciduous. In the Beech, the Fig, the 

 Magnolia, &c., they form the tegmenta or protective coverings 

 of the buds, and fall off as those open. 



The stipules vary in their position with regard to the petiole 

 and to each other, and have received different names accord- 

 ingly. Thus, when they adhere on each side to the base of the 

 petiole, as in the Rose (Jig. 355), they are said to be adnate^ 



Fig. 355. 



Fig. 356. 



Fig. 355. A portion of a branch, r, of the common Rose {Eosa canina), a. 

 A prickle. 6. Bud in the axil of a compound leaf/, p. Petiole, s. Ad- 



nate or adherent stipules Fig. 356. Leaf of Pansy iViola tricolor) with 



large caulinary stipules at its base. 



adherent, or petiolar. When they remain as little leaflets on each 

 side of the base of the petiole, but quite distinct from it, as in 

 many Willows (Jig. 255), and Pansy (Jig. 356), they are called 

 caulinary. When the stipules are large, it sometimes happens 

 that they meet on the opposite side of the stem from which the 

 leaf grows, and become united by their outer margins, and thus 

 form one stipule, as in the Asti'agalus and Plane-tree, they are 

 then said to be synochreate, or opposite (Jig. 357); if under similar 

 circumstances they cohere by their inner margins, as in Melian- 

 thus annuus, and Houttuynia cordata (Jig. 358), they form a 

 solitary stipule which is placed in the axil of the leaf, and is 

 accordingly termed axillary; if such stipules cohere by both 



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