ANALYTICAL KEY. XXV 



Four or five, generally as many as the lobes of the corolla. 

 Flowers in an involucrate head : stipules none. 17G (56) Dipsace^e. 

 Flowers if in heads not involucrate. 



Leaves whorled without stipules. ■> 



Leaves opposite, or rarely whorled, with i- 16S (56) Rubiace.e. 



stipules. j 



Leaves opposite without stipules (or some- 

 times with appendages to the petioles 

 imitating them). „ . . 163 (55) Caprifoliace.e. 



* * Ovary free from the calyx (superior). 



*- Corolla irregular: stamens (with anthers) 4 and didynamous, or only 2. 



Ovules and seeds solitary in the (1-4) cells. 



" Ovary 4-lobed. the style rising from between the lobes. 300 (67) Labiatje. 



Ovary not lobed, the style from its apex. . . 298 (66) Verbexace.e. 



Ovules numerous or as many as 2 in each cell. 



Ovary and pod 1-cellcd, 



With a free central placenta : stamens 2 : aquatics. 275 Lentibulace^e. 



With 2 or more parietal placentas : stamens 4. 



Plants with ordinary foliage (63) Gesneriace,e. 



Plants leafless, root-parasitic. . . . 279 Orobanciiace.e. 



Ovary and fruit more or less 4- 5-celled. Martynia. | , c _ 



^ , „,,,„, . ' ( 278 63 Bignoxiace.e. 



Ovary and pod 2-celled, but the 2 placenta; parietal. ) 



Ovary and pod 2-celled : placenta? in the axis. 



Seeds numerous, rarely few, not on hooks, &c. 281 (64) Scropiiulariace.e. 



Seeds few, borne on hook-like, or slender, or else cup- 



ehaped projections of the placentae. . 296 (66) Acantiiack-e. 



+-■*- Corolla somewhat irregular : stamens (with anthers) 5. 



Stamens free from the corolla or nearly so : anthers open- 

 ing by a hole at the top of each cell. . Azalea, 245 (61) Ericaceae. 

 Stamens inserted on the corolla. 



Filaments or some of them woolly. Verbascum, 281 Scrophulariacic.e. 



Filaments not woolly 338 (71) Solanace^e. 



-) — i — i— Corolla regular. 

 ++ Stame?is as many as the lobes of the corolla. 



Ovaries 2, separate ; their 



Styles and stigmas also wholly separate. Dichondra, 332 Convolvulace.e. 

 Stigmas and sometimes styles united into one. 



Filaments distinct : pollen in ordinary grains. 349 (73) Apocynaceje. 



Filaments commonly monadelphous : anthers united 



with the stigma : pollen in masses. . 350 (72) Asclepiadace^e. 

 Ovary one, but deeply 4-lobed around the style. 319 (69) B.orraqinace.e. 



