ants, with curious flowers and compound leaves. The garden
bleeding-heart (_Dicentra spectabilis_) and the pretty, wild
_Dicentras_ (Fig. 103, _F_) are familiar to nearly every one.

Other examples are the mountain fringe (_Adlumia_), a climbing
species, and several species of _Corydalis_, differing mainly from
_Dicentra_ in having the corolla one-sided.

The mustard family (_Cruciferae_) comprises by far the greater part of
the order. The shepherd's-purse, already studied, belongs here, and
may be taken as a type of the family. There is great uniformity in all
as regards the flowers, so that the classification is based mainly on
differences in the fruit and seeds. Many of the most valuable garden
vegetables, as well as a few more or less valuable wild plants, are
members of the family, which, however, includes some troublesome
weeds. Cabbages, turnips, radishes, with all their varieties, belong
here, as well as numerous species of wild cresses. A few like the
wall-flower (_Cheiranthus_) and stock (_Matthiola_) are cultivated for
ornament.

The last family is the caper family (_Capparideae_), represented by
only a few not common plants. The type of the order is _Capparis_,
whose pickled flower-buds constitute capers.

The fourth order (_Cistiflorae_) of the _Aphanocyclae_ is a very large
one, but the majority of the sixteen families included in it are not
represented within our limits. The flowers have the sepals and petals
in fives, the stamens either the same or more numerous.

[Illustration: FIG. 104.--Types of _Aphanocyclae_ (_Cistiflorae_). _A_,
flower of wild blue violet, _Viola_ (_Violaceae_), x 1. _B_, the lower
petal prolonged behind into a sac or spur, x 1. _C_, the stamens, x 2.
_D_, pistil, x 2. _E_, a leaf, x 1/2. _F_, section of the ovary, x 2.
_G_, the fruit, x 1. _H_, the same after it has opened, x 1. _I_,
diagram of the flower. _J_, flower of mignonette, _Reseda_
(_Resedaceae_), x 2. _K_, a petal, x 3. _L_, cross-section of the
ovary, x 3. _M_, fruit, x 1. _N_, plant of sundew, _Drosera_
(_Droseraceae_), x 1/2. _O_, a leaf that has captured a mosquito, x 2.
_P_, flower of another species (_D. filiformis_), x 2. _Q_,
cross-section of the ovary, x 4.]

Among the commoner members of the order are the mignonettes
(_Resedaceae_) and the violets (_Violaceae_), of which the various wild
and cultivated species are familiar plants (Fig. 104, _A_, _M_). The
sundews (_Droseraceae_) are most extraordinary p