164 DICOTYLEDONS 
GROUPS AND ORDERS OF THE SUB-CLASS 
CHORIPETALS, OF THE CLASS DICOTY- 
LEDONS, DIVISION OF ANGIOSPERMS. 
Class II.—DICOTYLEDONS 
Embryo with two lobes (see page 50). Leaves generally net- 
veined. In a few cases, by abortion of a cotyledon, there is an 
apparent condition of monocotyledonism. In a number of in- 
stances also the leaves are constructed nearly on the parallel- 
veined plan. 
Dicotyledons are divided into two great sub-classes. In the 
flowers of the first sub-class the petals are separate as in the 
case of the buttercups, violets, pinks, etc., while in the flowers of 
the second sub-class the petals are so united that, in general, they 
appear as a single envelope as in the case of the hare bells, the 
mints, the huckleberry tribe and others. 
Curiously, a large group in which no petals are to be seen, be- 
longs to the first sub-class, since it is assumed that although the 
petals are little or not at all apparent they are technically present 
_but suppressed. 
The first sub-class, CHORIPETALAE,* then, is composed of two 
GROUPS, in a certain sense artificial, but convenient for our pur- 
pose: 
Plants whose flowers have no apparent petals and, gen- 
erally, only very rudimentary envelopes. 1st Group. 
MPN ete aee eee )s ) APETALAE 
Plants whose flowers have, generally, several petals or 
colored sepals which are distinctly petaloid. 2d 
jroup . |. ww Ge ee ae > 6) VOL 
In the second sub-class GAMOPETALAR, the petals are united, but 
in a few exceptional cases nearly or quite separated. 
* Gr. Choris, asunder: petalon, a petal. 
