18 ANALYTICAL KEY 



Calyx 5-lobed or of 5 equal sepa/s Saxifragaceae, 444 



Calyx of 3 equal or 5 very unequal sepals Cistaceae, 570 



A.. Ovary 2-several-celled B. 

 B. Flowers irregular C. 

 C. Anthers opening at the top. 



Anthers 6-8, 1-celled Polygal-Aceae, 538 



Anthers 10, 2-celled Rhododendron, 631 



C. Anthers opening lengthwise. 



Stamens 12 and petals 6 on the throat of the gibbous calyx Cuphea, 593 

 Stamens 5-10 and petals hypogjiious or nearly so. 



Ovary 3-celled ; trees or shrubs Aesculus, 559 



Ovary 5-celled ; herbs Balsaminaceae, 560 



B. Flowers regular or nearly so D. 



D. Stamens neither just as many nor twice as many as the 

 petals. 

 Trees or shrubs. 

 Stamens fewer than the 4 petals Oleaceae, 650 



Stamens more numerous than the petals Aceraceae, 557 



Herbs. 

 Petals 5 Hypericaceae, 571 



Petals 4 Cruciferae, 418 



D. Stamens just as many or twice as many as the petals E. 

 E. Ovules and seeds only 1 or 2 in each cell. 

 Herbs. 

 Flowers monoecious or dioecious Euphorbiaceae, 540 



Flowers perfect and symmetrical. 

 Cells of the ovary as many as the sepals. 

 Ovary 2-3-cened Limnanthaceae, 551 



Ovary 5-celled Geraniaceae, 534 



Cells of the ovary twice as many as the sepals. 

 Leaves abruptly pinnate Zygophyllaceae, 536 



Leaves simple Linaceae, 531 



Shrubs or trees. 

 Leaves compound. 

 Leaves ;3-foliolate, punctate Ptelea, 537 



Leaves pinnate, not punctate Sapindaceae, 559 



Leaves simple. 

 Leaves palmately veined Aceraceae, 557 



Leaves pinnately veined. 

 Leaves alternate. 



Climbing shrub Celastrus, 557 



Erect shrubs or trees. 



Flowers racemose Cyril lack a k, 553 



Flowers solitary or cymose Aquifoliaceae, 554 



Leaves opposite Celastraceae, 556 



E. Ovules, and usually seeds, several or many in each cell F. 

 F. Leaves compound. 



Tree or shrub Staphyleaceae, 557 



Herbs ; leaves alternate, or all radical. 

 Leaflets 3, obcordate Oxalidaceae, 532 



Leaflets more numerous, pointed Astilbe, 444 



F. Leaves simple. 



Stipules present between opposite leaves Elatinaceae, 575 



