KEY TO FAMILIES xxvii 



(m) Petals very hairy on the upper 



face MENYANTHACEAE 



99 



(n) Petals smooth 

 r. Flowers regular; terrestrial HYDROPHYLLACEAE 



116 



s. Flowers irregular ; aquatic PINGUICULACEAE 139 

 (y) Carpels 5 PRIMULACEAE 88 



y. Ovary 2-celled, 2-divided or 4-lobed 

 (x) Ovary 2-celled or 2-divided 

 m. Leafless herbs; plants not green 

 (m) Stems twining; flowers regu- 

 lar CUSCUTACEAE 109 



(n) Stems not twining; flowers ir- 

 regular OROBANCHACEAE 140 

 n. Leafy herbs 

 (m) Stamens 5 

 r. Ovary 2-lobed or pistils 2 and 



separate 

 (r) Stamens distinct, around a 



crown ASCLEPIADACEAE 101 



(s) Stamens united; crown 



none APOCYNACEAE 100 



s. Ovary 1, 2-celled, not 2-lobed 

 (r) Seeds 2-several; mostly 



climbing or trailing CONVOLVULACEAE 



108 



(s) Seeds many SOLANACEAE 110 



(n) Stamens 4 



r. Corolla brightly colored, the 



lobes usually 5 

 (r) Fruit a 2-celled capsule SCROPHULARIACEAE 



125 



(s) Fruit 2 or 4 1-seeded nut- 

 lets VERBENACEAE 142 

 s. Corolla papery, the lobes 4 PLANT AGINACEAE 92 

 (y) Ovary 4-lobed or divided 

 m. Flowers usually irregular; leaves 



opposite LAMIACEAE 143 



