xu 



KEY TO THE FAMILIES. 



Stamens alternate with the corolla-lobes or 

 fewer. 

 Ovar>- inferior. 



Tendril-bearing herbs. 

 Tendrils none. 



Flowers in an involucrate head on a 

 common receptacle. 

 Anthers united into a ring or 



tube (syngenesious). 

 Anthers not united. 

 Flowers not in an involucrate head 

 nor on a common receptacle. 

 Stamens on the ovary. 

 Stamens on the corolla. 

 Stamens 1-3. 

 Stamens 4 or 5. 



Leaves opposite or whorled, 

 w^hen opposite with stip- 

 ules. 

 Leaves opposite, without 

 stipules. 

 Ovarj^ superior. 



Corolla more or less irregular. 



Ovules solitary in the cells of the 

 ovary. 

 Ovary 4-lobed, the style rising 



from between the lobes. 

 Ovary not lobed, the style rising 

 from its apex. 

 Ovules 2 or more, usually numerous, 

 in each cell. 

 Ovary and pod 2-celIed. 

 Ovary and pod 1-celled. 



Chlorophyll-less terrestrial 



herbs. 

 Chlorophyll-bearing aquatic 

 herbs. 

 Corolla regular. 



Stamens fewer than the corolla-lobes. 

 Trees or shrubs. 

 Herbs. 



Corolla scarious. 

 Corolla not scarious. 

 Style 2-lobed. 

 Style simple. 

 Stamens as many as the corolla-lobes. 

 Ovaries 2, separate. 

 Ovary 1. 



Ovary deeply 4-lobed around 

 the style. 

 Leaves alternate. 

 Leaves opposite. 

 Ovary not deeply lobed. 

 Ovary 1-celled. 



Leaves entire, opposite. 

 Leaves alternate or 

 basal, rarely en- 

 tire. 



CUCURBITACEAE, 341. 



COMPOSITAE, 345. 

 DiPSACACEAE, 341. 



Campanulaceae, 342. 

 Valerianaceae, 339. 



rubiaceae, 334. 

 Caprifoliaceae, 336. 



Labiatae, 306. 

 Verbenaceae, 305. 



Scrophulariaceae, 315. 



Orobanchaceae, 330. 

 Lentibulariaceae, 332. 



Oleaceae, 287. 



Plantaginaceae, 333. 



Lycopus, 307. 

 Veronica, 322. 



Apocynaceae, 290. 



Boraginaceae, 299. 

 Mentha, 308. 



Gentianaceae, 287. 



