†Stamens 3; flowers small, in terminal clusters. =Valerianaceæ.= ††Stamens 5. Opposite to the corolla lobes. =Primulaceæ.= Alternate with the corolla lobes. Stems smooth, leafy; corolla campanulate. Stem leaves broad; flowers pink. =Apocynaceæ.= Stem leaves narrow; flowers blue. =Campanulaceæ.= Stems rough-hairy. Corolla salver-form; stamens included. =Boraginaceæ.= Corolla tubular; stamens exserted. =Hydrophyllacæ.= †††Stamens 10; flowers mostly in terminal heads or singly. =Pyrolaceæ.= **Flowers irregular. (_a_) Leaves all entire and basal, forming rosettes; flowers blue. =Lentibulariaceæ.= (_b_) Leaves all heart-shaped; flowers blue, white or yellow. =Violaceæ.= (_c_) Leaves not heart-shaped, simple or much cut, not pinnate. Stems square; flowers in close verticels in the axils of the leaves or in terminal heads. =Menthaceæ.= Stems round; flowers numerous in elongated terminal leafy heads or few on slender stems in the axils of the upper leaves. =Scrophulariaceæ.= (_d_) Leaves palmate; flowers blue in elongated spikes. =Ranunculaceæ.= (_e_) Leaves pinnately divided; flowers pea-like. =Papilionaceæ.= (_f_) Leaves compoundly lobed, not pinnate. Stems low, spreading, flowers small in dense terminal or axillary spikes. =Papaveraceæ.= Stems erect; flowers drooping in open terminal heads, either showy and spurred or not showy and without spurs; leaves maiden-hair fern-like.