156 VARIETIES OF VERNATION. 
rolled up from one margin into a single coil, with the other 
margin exterior (jig. 298), as in the Apricot and Banana, in 
which case it is convolute ; 3rd, the two margins of the leaf may 
both be rolled inwards on the upper surface of the leaf, towards 
the midrib, which remains, immovable (fig. 300), as in the 
Violet and Water-lily, when it is involute; or, 4th, the two 
margins may be rolled outwards or towards the midrib on the 
lower surface of the leaf (jig. 299), as in the Dock and Azalea, 
in which case it is revolute. 
We pass now to consider, secondly, the relation of the several 
leaves of the same bud taken as a whole to one another. Of 
this we have several varieties which may also be treated of in 
two divisions :—1st, those in which the component leaves are 
flat or slightly convex ; and 2nd, where they are bent or rolled. 
Of the first division we shall describe three varieties :—1st, that 
Fic. 301. Fie. 302. Fia. 303. 
~~ 
Fie. 304, Fie. 305. Fic. 306. Fic. 307. 
Fig. 301, Transverse section of a bud to show the leaves arranged in a val- 
vate manner. Fig. 302. Transverse section of a bud to show imbricate 
vernation. Fig. 303. Transverse section of a bud to show twisted or 
spiral vernation. Fig. 304, Transverse section of a bud to show indu- 
plicate vernation. Fig. 305. Transverse section of a bud showing equi- 
tant vernation. Fig.306 Transverse section of a bud showing obvolute 
vernation,— Fig. 307. Transverse section of a bud showing supervolute 
vernation. 
in which the leaves are placed nearly in a circle or at the same 
level, and in contact by their margins only, without overlapping 
each other (fig. 301), when they are valvate ; 2nd, that in which 
the leaves are placed at different levels, and the outer succes- 
sively overlap the inner to a greater or less extent by their mar- 
gins (fig. 302), as in the Lilac, and in the outer scales of the 
Sycamore, when they are said to be imbricate ; and 3rd, if when 
leaves are placed as in imbricate vernation, the margin of one 
leaf overlaps that of another, while it, in its turn, is overlapped 
by a third (fig. 303), the vernation is twisted or spiral, Of the 
second division, viz. where the component leaves of the bud are 
