stration: FIG. 118.--Types of _Anisocarpous sympetalae_
(_Tubiflorae_). _A_, flower and leaves of wild phlox (_Polemoniaceae_),
x 1/2. _B_, section of a flower, x 1. _C_, fruit, x 1. _D_, flower of
blue valerian (_Polemonium_), x 1. _E_, flowers and leaf of
water-leaf, _Hydrophyllum_ (_Hydrophyllaceae_), x 1/2. _F_, section of a
flower, x 1. _G_, flower of wild morning-glory, _Convolvulus_
(_Convolvulaceae_), x 1/2. One of the bracts surrounding the calyx and
part of the corolla are cut away. _H_, diagram of the flower. _I_, the
fruit of a garden morning-glory, from which the outer wall has fallen,
leaving only the inner membranous partitions, x 1. _J_, a seed, x 1.
_K_, cross-section of a nearly ripe seed, showing the crumpled embryo,
x 2. _L_, an embryo removed from a nearly ripe seed, and spread out;
one of the cotyledons has been partially removed, x 1.]

The first order (_Tubiflorae_) has, as the name indicates, tubular
flowers which show usually perfect, radial symmetry (_Actinomorphism_).
There are five families, all represented by familiar plants. The first
(_Convolvulaceae_) has as its type the morning-glory (_Convolvulus_)
(Fig. 118, _G_), and the nearly related _Ipomoeas_ of the gardens. The
curious dodder (_Cuscuta_), whose leafless, yellow stems are sometimes
very conspicuous, twining over various plants, is a member of this
family which has lost its chlorophyll through parasitic habits. The
sweet potato (_Batatas_) is also a member of the morning-glory family.
The numerous species, wild and cultivated, of phlox (Fig. 118, _A_),
and the blue valerian (_Polemonium_) (Fig. 118, _D_), are examples of
the family _Polemoniaceae_.

[Illustration: FIG. 119.--_Anisocarpous sympetalae_ (_Tubiflorae_). _A_,
inflorescence of hound's-tongue, _Cynoglossum_ (_Borragineae_), x 1/2.
_B_, section of a flower, x 2. _C_, nearly ripe fruit, x 1. _D_,
flowering branch of nightshade, _Solanum_ (_Solaneae_), x 1/2. _E_, a
single flower, x 1. _F_, section of the flower, x 2. _G_, young fruit,
x 1. _H_, flower of _Petunia_ (_Solaneae_), x 1/2. _I_, diagram of the
flower.]

The third family (_Hydrophyllaceae_) includes several species of
water-leaf (_Hydrophyllum_) (Fig. 118, _E_) and _Phacelia_, among our
wild flowers, and species of _Nemophila_, _Whitlavia_ and others from
the western states, but now common in gardens.

The Borage family (_Borragineae_) includes the forget-me-not
(_Myosotis_) and a few pretty wild flowers, _e.