ANALYTICAL KEY TO THE FAMILIES. 



Division 2. Gamopetalae: calyx and corolla usually present, the petals 

 more or less united. Polypetalous forms occur in the Asclepiada- 

 ceae, Oleaceae, Pyrolaceae, and the Monotropaceae, and apetalous 

 forms occur in the Oleaceae as noted at the end of the key. 



A. Stamens inure numerous than the lobes of the corolla. 

 Stamens free from the corolla or merely adnate to its base. 

 Ovary superior, 4-5-celled; f ruit a cupsule. 

 Low evergreen perennials. Pyrolaceae, 102. 



"Waxy-white parasitic plants. Monotropaceae, 103. 



Ovary inferior, adnate to the calyx; fruit a many-seedfid berry. 



Vacciniaceae, 103. 

 Stamens borne on the tube or at the base of the corolla. 

 Leaves alternate. Ebenaceae, 105. 



Leaves opposite and basal. Adoxaceae, 69. 



B. Stamens as many as the lobes of the corolla and inserted on the tube opposite 

 the lobes. PRIMULACEAE, 104- 



C. Stamens as many as the lobes of the corolla and inserted alternate with them, or 

 feirer. 



* Ocari/ inferior, adherent to the caly.r-tube. 

 f Anthers united, except in Knhnia of the Compositae, Vie Ambrosiaceae, and 

 many of tin; Campanulaeeac. 

 Flowers in involucrate heads. 

 Flowers all ligulate; juice milky. Cichoriaceae, 97. 



Flowers tubular or the outer ligulate; juice rarely milky. 

 Stamens distinct or nearly so. Ambrosiaceae, 95. 



Stamens united by their anthers around the style. Compositae, 72. 

 Flowers not in involucrate heads. Campanulaceae, 101. 



f f Stamens inserted on the corolla : anthers separate. 

 Stamens in ours 3, fewer than the corolla-lobes. Valerianaceae, 71. 



Stamens as many as the corolla-lobes, one less in Linnaca of the Caprifoliaceae. 

 Leaves opposite or verticillate, usually stipulate. Rubiaceae, 70. 



Leaves opposite, exstipulate. Caprifoliaceae, 67. 



* * Geary superior. 

 f Corolla irregular, more or less ..'-lipped; stamens 4 and didynamvus, or only ..'. 



X Carpels 1 — ..'-seeded. 

 Ovary 4-lobed, becoming 4 1-aeeded nutlets. Labiatae, 131. 



Ovary not lobed; carpels separating into 1-seeded nutlets. Verbenaceae, 130. 



X X Carpels 2 — many-seeded. 

 O vary 1-celled ; stamens 2; marsh or aquatic herbs. Lentibulariaceae, 128. 

 Ovary 1-celled; stamens 4; brownish or whitish parasitic herbs. 



Orobanchaceae, 127. 



Ovary 1 celled or becoming partially 4-celled; fruit with 2 long recurved 



beaks. Martyniaceae, 129. 



Ovary and capsule 2-celled; placentae parietal; seeds winged in our species; 



small trees or woody vines. Bignoniaceae, 128. 



Ovary and capsule 2-celled; placentae axile. 



Seeds usually many. Scrophulariaceae, 120. 



Seeds few, borne on curved projections. Acanthaceae, 129. 



f f Corolla someirhat irregular; stamens .7. 



Ovary deeply 4-lobed. Echium, in Borraginaceae, 112. 



