The External Form of Plants. 85 
covered by one of the outer leaves. If the whole bud ap- 
pears as if twisted spirally, the zestivation is said to be con- 
torted; if, as in the poppy, the leaves lie in the bud 
irregularly crumpled up, it is crumpled. 
p 
wy 
a, 
se a 
Ye 
Eo 
Fic. 128.—Vexil- Fic. 129.—Alternate Fic. 130.—Quincun- Fic. 131.—Contorted 
lary estivation — zestivation of tulip. cial zstivation. zestivation. 
of Papiliona- 
COX. 
/ ‘By vernation is meant the position occupied by the se- 
| parate leavesin the bud. This 1s #a¢ in the leaves of Coni- 
fere ; simply fo/ded (Fig. 132) in those of the cherry and lime ; 
plicate or with many folds in those of the beech and birch 
Fig. 133). In their length from the apex to the base leaves 
Fic. 135.—Revolute 
vernation. 
| ( i ) 
Fic. 132. — Fie: 3133. — Fie. 134.—Con- Fic. 136.—Involute Fic. 137.—Contorted 
Simply fold- Plicate ver- volute  verna- vernation. vernation. 
ed sverna- nation. tion. 
tion. 
are crcinate, like the fronds of ferns, where the apex is 
rolled up towards the base ; convolute (Fig. 134), where one 
margin is rolled up towards the mid-rib, as in grasses and 
bananas. The sepals of FAumaria are revolute, the margins 
being rolled outwards (Fig. 135); those of the sweet violet 
