iv.] WALLFLOWER. 23 



(or Carrot), Daisy (or Ox-eye), White or Purple Dead- 

 nettle, Primrose, Stinging Nettle, Willow, Arum or 

 Cuckoo Pint, Spotted Orchis, Daffodil, Tulip, Wheat, 

 Scotch Fir. 



There are three conditions which play a most important 

 part in modifying the structure of flowers, to which we 

 must direct attention before proceeding. These are 

 cohesion, adhesion, and suppression. The first two terms 

 are used by botanists to denote the union of like (cohesion) 

 or unlike (adhesion) parts of the flower. Thus union of 

 sepals with sepals, of petals with petals, of stamen with 

 stamen, of carpel with carpel, is said to be due to cohesion 

 parts of the same whorl or series being concerned. 

 Union of corolla to stamens, or ovary to calyx, or of 

 stamens to corolla or to pistil, is due to adhesion parts 

 of different whorls or series being concerned. 



The term suppression is used to denote the absence of 

 parts in a flower, which, from analogy, we might expect 

 to find. Thus we shall find that in some flowers the 

 corolla is suppressed, in others the corolla and stamens, 

 or the corolla and pistil. Sometimes but a single series 

 of organs, either stamens or pistil, constitutes the flower, 

 the three other series being suppressed. Single parts of 

 a series, also, as a sepal, a petal, &c., when absent are 

 said to be suppressed. 



2. In the BUTTERCUP neither cohesion, adhesion, nor 

 suppression of parts occurs : hence its flo\vers consist of 

 four series of organs. We have a 



Calyx .... inferior and . . polysepaloits 



Corolla ) , , ( fiolyfietalous 



Stamens \ ' ' *yP<W*** - \%l/androus 



Pistil .... superior . . . apocarpous 



In the examination of the flowers now before us we shall 

 find manifold variety in respect to these conditions of 

 cohesion, adhesion, and suppression. 



3. WALLFLOWER. There are four free sepals, four 

 free equal petals, and six free stamens, of which four are 

 long and two short (hence called tetradynamous]. The 

 pistil at first sight looks as though it consisted of a single 

 carpel ; but you may observe that the stigma is indis- 

 tinctly tvvo-lobed. This would indicate that we have two 



