[Illustration: FIG. 118.--Types of _Anisocarpous sympetalæ_ (_Tubifloræ_). _A_, flower and leaves of wild phlox (_Polemoniaceæ_), × ½. _B_, section of a flower, × 1. _C_, fruit, × 1. _D_, flower of blue valerian (_Polemonium_), × 1. _E_, flowers and leaf of water-leaf, _Hydrophyllum_ (_Hydrophyllaceæ_), × ½. _F_, section of a flower, × 1. _G_, flower of wild morning-glory, _Convolvulus_ (_Convolvulaceæ_), × ½. 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, × 1. _J_, a seed, × 1. _K_, cross-section of a nearly ripe seed, showing the crumpled embryo, × 2. _L_, an embryo removed from a nearly ripe seed, and spread out; one of the cotyledons has been partially removed, × 1.] The first order (_Tubifloræ_) 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 (_Convolvulaceæ_) has as its type the morning-glory (_Convolvulus_) (Fig. 118, _G_), and the nearly related _Ipomœas_ 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 _Polemoniaceæ_. [Illustration: FIG. 119.--_Anisocarpous sympetalæ_ (_Tubifloræ_). _A_, inflorescence of hound's-tongue, _Cynoglossum_ (_Borragineæ_), × ½. _B_, section of a flower, × 2. _C_, nearly ripe fruit, × 1. _D_, flowering branch of nightshade, _Solanum_ (_Solaneæ_), × ½. _E_, a single flower, × 1. _F_, section of the flower, × 2. _G_, young fruit, × 1. _H_, flower of _Petunia_ (_Solaneæ_), × ½. _I_, diagram of the flower.] The third family (_Hydrophyllaceæ_) 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 (_Borragineæ_) includes the forget-me-not (_Myosotis_) and a few pretty wild flowers, _e.g._ the orange-flowered puccoons (_Lithospermum_); but it also embraces a number of the most troublesome weeds, among which are the hound's-tongue (_Cynoglossum_) (Fig. 119, _A_), and the "beggar's-ticks" (_Echinospermum_), whose prickly fruits (Fig. 119, _C_) become detached on the slightest provocation, and adhere to whatever they touch with great tenacity. The flowers in this family are arranged in one-sided inflorescences which are coiled up at first and straighten as the flowers expand.