KEY TO FAMILIES. 13 



c. Stamens perigynous, i. e., on the calyx or on a more or less evident disk. 

 Stamens on a hypogynous disk or on a disk lining the base of the calyx; trees 

 OT shrubs. 

 Leaves simple; corolla regular; petals usually 5 (4 to 6). 

 Stamens 5 (or 4), ns many as the petals and opposite them. 



Shrubs; petals hooded; fruit 3 (or 2) -celled, dry and splitting into 



3 (or 2) one-seeded parts Rhamnaceae, p. 251. 



Woody vine climbing by tendrils; petals not hooded, caducous; fruit 



a berry Vitaceae, p. 256. 



Stamens 5 (4 to 6), as many as the petals and alternate with them; fruit 

 a 3 to 5-celled capsule; seeds with an aril. . . Celastraceae, p. 249. 



Stamens 3 to 10 ; fruit a double samara Acer, p. 250. 



Leaves compound ; petals 5 or 4. 



Stamens 5 to 8; petals claAved, slightly irregular; fruit a 1-seeded capsule; 



leaves opposite, palmate Sapindaceae, p. 251. 



Stamens (in ours) as many as the petals; corolla regular; leaves alter- 

 nate, trifoliolate. 



Styles or stigmas 3; fruit drupe-like Axacardiaceae, p. 248. 



Style 1; fruit a 2-celled, 2-seeded samara Rutaceae, p. 248. 



Stamens on the calyx; corolla regular. 



Stipules present; pistils one to several, sometimes partly united to the disk; 

 petals 5; stamens 10 to numerous; leaves alternate, often compound.. 



Rosaceae, p. 203. 

 Stipules none; leaves simple. 



Pistils many, concealed in a hollow receptacle; stamens numerous; leaves 



opposite Calycanthaceae, p. 172. 



Pistil 1 ; stamens 4 to 10. 



Styles or stigmas more than 1; capsule not enclosed by the calyx 



Saxifragaceae, p. 197. 



Style and stigma 1; capsule enclosed by but free from the calyx 



Lythraceae, p. 271. 

 B. Ovary inferior, i. e., more or less adherent to the calyx. 

 1. Trees and shrubs. 

 Stamens more numerous than the petals; petals .">. 



Leaves alternate; fruit a pome Rosaceae, p. 203. 



Leaves opposite; fruit a capsule; trailing undershrub Whipplea, p. 201. 



Stamens as many as the petals and opposite them; petals 5, hooded; capsule 



3-celled, 1 seed in each cell Ceaxothus, p. 252. 



Stamens as many as the petals and alternate with them. 



Petals 4; style 1; flowers small, in cymes, or if in a head, surrounded by a 

 conspicuous corolla-like involucre; fruit drupe-like; leaves opposite.... 



Cornaceae, p. 304. 

 Petals (in ours) 5; styles 2, more or less distinct; flowers in racemes or soli- 

 tary; fruit a smooth or prickly berry; leaves alternate, with stipules... 



Ribes, p. 201. 

 2. Herbs. 

 Petals and stamens numerous; fruit 10 to 12-celled, dehiscing at summit; suc- 



eulenl maritime herb MJSSEMBRYANTHEMUM, p. 150. 



Petals 5 or fewer. 

 Flowers in umbels. 



Umbels compound, often simple, sometimes capitate; styles 2; fruit split- 

 ting into 2 one-seeded carpels Umbeluferae, p. 285. 



