pery wall at the bottom, and the stiff,
downward-directed hairs above, prevent their escape, and they fall
into the fluid which fills the bottom of the cup and are drowned, the
leaf absorbing the nitrogenous compounds given off during the process
of decomposition. There are other species common in the southern
states, and a California pitcher-plant (_Darlingtonia_) has a colored
appendage at the mouth of the pitcher which serves to lure insects
into the trap.

Another family of pitcher-plants (_Nepentheae_) is found in the warmer
parts of the old world, and some of them are occasionally cultivated
in greenhouses. In these the pitchers are borne at the tips of the
leaves attached to a long tendril.

Two other families of the order contain familiar native plants, the
rock-rose family (_Cistaceae_), and the St. John's-worts
(_Hypericaceae_). The latter particularly are common plants, with
numerous showy yellow flowers, the petals usually marked with black
specks, and the leaves having clear dots scattered through them. The
stamens are numerous, and often in several distinct groups (Fig. 105,
_C_, _D_).

The last order of the _Aphanocyclae_ (the _Columniferae_) has three
families, of which two, the mallows (_Malvaceae_), and the lindens
(_Tiliaceae_), include well-known species. Of the former, the various
species of mallows (Fig. 106, _A_) belonging to the genus _Malva_ are
common, as well as some species of _Hibiscus_, including the showy
swamp _Hibiscus_ or rose-mallow (_H. moscheutos_), common in salt
marshes and in the fresh-water marshes of the great lake region. The
hollyhock and shrubby _Althaea_ are familiar cultivated plants of this
order, and the cotton-plant (_Gossypium_) also belongs here. In all of
these the stamens are much branched, and united into a tube enclosing
the style. Most of them are characterized also by the development of
great quantities of a mucilaginous matter within their tissues.

The common basswood (_Tilia_) is the commonest representative of the
family _Tiliaceae_ (Fig. 106, _G_). The nearly related European linden,
or lime-tree, is sometimes planted. Its leaves are ordinarily somewhat
smaller than our native species, which it, however, closely resembles.

[Illustration: FIG. 106.--Types of _Aphanocyclae_ (_Columniferae_). _A_,
flower and leaf of the common mallow, _Malva_ (_Malvaceae_), x 1/2. _B_,
a flower bud, x 1. _C_, section of a flower, x 2. _D_, the fruit, x 2.
_E_, section of