138 THE FLOWER 



foramen or orifice is at the apex. This is the simplest, but the least 

 common, kind of ovule. 



Campylotropous, or incurved, in which, by the greater growth of one 

 side, the ovule curves into a kidney-shaped outline, so bringing' the 

 orifice down close to the base or chalaza ; as in Fig. 233. 



Amphitropous, or half-inverted, Fig. 234. Here the forming ovule, 

 instead of curving perceptibly, keeps its axis nearly straight, and, as 

 it grows, turns round upon its base so far as to become transverse to 

 its funiculus, and adnate to its upper part for some distance. There- 

 fore in this case the attachment of the funiculus or stalk is about the 

 middle, the chalaza is at one end, the orifice at the other. 



Anatropous, or inverted, as in Fig. 235, the commonest kind, so 

 called because in its growth it has as it were turned over upon its 

 stalk, to which it has continued adnate, the attached portions o the 

 stalk being known as the raphe. The organic base, or chalaza, thus 

 becomes the apparent summit. 



Arrangement of Parts in the Bud 



281. Estivation was the fanciful name given by Linnaeus to denote 

 the disposition of the parts, especially the leaves of the flower, before 

 anthesis, i.e. before the blossom opens. Prcefloration, a better term, is 

 sometimes used. This is of importance in distinguishing different 

 families or genera of plants, being generally uniform in each. The 

 aestivation is best seen by making a cut across the flower bud ; and 

 it may be expressed in diagrams, as in the accompanying figures. 



ff 



y 



240 



282- The pieces of the calyx or the corolla either overlap each 

 other in the bud, or they do not. When they do not overlap, the 

 aestivation is 



Valvate, when the pieces meet each other by their abrupt edges, 

 without any infolding or overlapping, as in the calyx of the Linden or 

 Basswood (Fig. 236). 



Induplicate, which is valvate with the margins of each piece project- 

 ing inwards, as in the calyx of a common Virgin's-bower (Fig. 238), or 



Involute, which is the same, but with the margins rolled inward, 

 as in most of the large-flowered species of Clematis (Fig. 239). 



Reduplicate, a rarer modification of valvate, is similar, but with 

 margins projecting outward. 



Open, the parts not touching in the bud, as the calyx of Mignonette. 



