[Illustration: FIG. 116.--Types of _Isocarpous sympetalæ_ (_Bicornes_). _A_, flowers, fruit, and leaves of huckleberry, _Gaylussacia_ (_Vaccinieæ_), × 1. _B_, vertical section of the flower, × 3. _C_, a stamen: i, from in front; ii, from the side, × 4. _D_, cross-section of the young fruit, × 2. _E_, flower of sorrel-tree, _Oxydendrum_ (_Ericaceæ_), × 2. _F_, flower of azalea (_Rhododendron_), × ½. _G_, cross-section of the ovary, × 3. _H_, diagram of the flower. _I_, flower of mountain laurel (_Kalmia_), × 1. _J_, prince's-pine, _Chimaphila_ (_Pyrolaceæ_), × ½. _K_, a single flower, × 1. _L_, plant of pine-sap, _Monotropa_, (_Monotropeæ_), × ½. _M_, section of a flower, × 1.] The second order, the primroses (_Primulinæ_), is principally represented in the cooler parts of the world by the true primrose family (_Primulaceæ_), of which several familiar plants may be mentioned. The genus _Primula_ includes the European primrose and cowslip, as well as two or three small American species, and the commonly cultivated Chinese primrose. Other genera are _Dodecatheon_, of which the beautiful shooting-star (_D. Meadia_) (Fig. 117, _A_) is the best known. Something like this is _Cyclamen_, sometimes cultivated as a house plant. The moneywort (_Lysimachia nummularia_) (Fig. 117, _D_), as well as other species, also belongs here. [Illustration: FIG. 117.--_Isocarpous sympetalæ_ (_Primulinæ_, _Diospyrinæ_). _A_, shooting-star, _Dodecatheon_ (_Primulaceæ_), × ½. _B_, section of a flower, × 1. _C_, diagram of the flower. _D_, Moneywort, _Lysimachia_ (_Primulaceæ_), × ½. _E_, a perfect flower of the persimmon, _Diospyros_ (_Ebenaceæ_), × 1. _F_, the same, laid open: section of the young fruit, × 2. _H_, longitudinal section of a ripe seed, × 1. _em._ the embryo. _I_, fruit, × ½.] The sea-rosemary (_Statice_) and one or two cultivated species of plumbago are the only members of the plumbago family (_Plumbagineæ_) likely to be met with. The remaining families of the _Primulinæ_ are not represented by any common plants. The third and last order of the _Isocarpous sympetalæ_ has but a single common representative in the United States; viz., the persimmon (_Diospyros_) (Fig. 117, _E_). This belongs to the family _Ebenaceæ_, to which also belongs the ebony a member of the same genus as the persimmon, and found in Africa and Asia. The second division of the _Sympetalæ_ (the _Anisocarpæ_) has usually but two or three carpels, never as many as the petals. The stamens are also never more than five, and very often one or more are abortive.