DICOTYLEDONS 2138 
less completely united, and the corolla is “sympetalous,” 
or “gamopetalous.” The greater number of these, in 
addition to their being more highly specialized, indicate 
that they are, as a 
whole, a later and 
more differentiated 
group than the Cho- 
ripetale, although it 
must be remembered 
that certain families 
of the latter are 
highly specialized. 
The highest of the 
Sympetale, how- 
ever, are probably 
the most recent and 
Fic. 52 (Sympetale).—A, flower of wild 
Azalea (A. viscosa), one of the isovarpous 
Sympetale ; all the parts of the flower in 
highly developed of 
all plants. 
The Sympetale 
fall readily into two 
main divisions, the 
Isocarpe, which 
have the carpels 
equal in number to 
the petals, and the 
fives ; B, a section of the ovary of Azalea, 
showing the five divisions; C, flower of 
the pine-sap (Monotropa), the petals and 
sepals quite separate; D, flower of the 
sorrel-tree (Oxydendrum), the petals co- 
herent almost to the tips; E, flower of 
shooting-star (Dodecatheon), one of the 
primrose family; F, flower of Petunia, 
one of the anisocarpous Sympetale; 
parts of the flower in fives, except the 
two carpels, shown in the cross-section 
of the ovary, G. 
Anisocarpe, in which they are fewer. None of the Sym- 
petale ever have the carpels separate, but they are 
always completely united into a compound pistil. The 
Isocarpe are supposed to be the more primitive of the 
two divisions, and a few of them have the petals almost 
free (Fig. 52, C), and to some extent connect the Cho- 
ripetale and Sympetale. Of these isocarpous forms the 
