THE AMERICAN BOTANIST 121 



)s (12) 



12 Flowers lacking a perinanth (13) 



13 Flowers in spikes. Piperaceae. (G. 320. B. 307) 



13 Flowers solitary, minute. 



Stamens numerous, leaves whorled, dissected. Ceratophyllaceae. (G. 389. B. 408) 

 Stamens and styles, one or two. 



Leaves opposite. Callitrichiaceae. (G. 549. B. 596) 



Leaves alternate. Podostemaceae. (G. 441. B. 472) 



12 Flowers with calyx or calyx-like involucre (14) 

 14 Ovary inferior (15) 



15 Stamens five, style one. Santalaceae. (G. 349. B. 345) 



15 Stamens more or less than five, styles various. 



Stamens six or twelve. Aristolochiaceae. (G. 351. B. 347) 



Stamens one to ten. 



Stigmas two. Saxifragaceae. (G. 444. B. 484) 



Stigmas one, three or four. Onagraceae. (G. 594. B. 651) 



14 Ovary superior, sometimes enclosed by the calyx (16) 

 16 Style or stigma one (17) 



17 Ovaries 4 or more, one ovuled. 



Stamens on the receptacle. Ranunculaceae. (G. 392. B. 411) 



Stamens on the calyx. Rosaceae. (G. 454. B. 490) 



17 Ovary one (18) 



18 One ovuled, one seeded. 



Flowers monoecious or dioecious. Urticaceae. (G: 344. B. 341) 



Flowers perfect, calyx entire, colored. Nyctagmaceae.(G. 375. B.382) 

 18 Many ovuled. 



Stamens four, opposite the sepals. Lythraceae. (G. 591. B. 648) 



Stamens five alternating with sepals. Primulaceae. (G. 643. B. 713) 



16 Styles and stigmas more than one (19) 



19 Ovules one to three ; stigmas two to five (20) 



20 Fruit three seeded. Euphorbiaceae (G. 540. B. 585) 



20 Fruit one seeded. 



Plants with stipules. 



Stipules sheathing the stem. 

 Stipules not sheathing. 



Plants without stipules. 

 Calyx scarious bracted. 

 Calyx naked. 



LeavcB alternate. 



Leaves opposite. 



19 Ovules four or more, styles two to twelve (21) 

 21 Leaves opposite. 



Fruit a capsule, four or five valved. Caryophyllaceae. (G. 377. B. 387) 

 Fruit a utricle, circumscissle. Portulaceae. (G. 387. B. 384) 



21 Leaves alternate. 



Fruit a berry, four to ten seeded. Phytolaccaceae. (G. 374. B.381) 

 Fruit dry. 



Capsule five celled. Crassulaceae. (G. 441. B. 473) 



Utricle, circumscissle. Amaranthaceae. (G. 371. B. 377) 



