ANALYTICAL KEY 13 



a. Ovary 1-2-celled; cells 1-ovuled ; fruit 1-seeded. 



Parasitic on trees ; fruit a berry Loranthaceae, 351 



Trees and shrubs, not parasitic. 

 Calyx regular, in fertile flower succulent in fruit Urticaceae, 344 

 Calyx none or rudimentary and scale-like. 

 Style and stigma 1, simple. 

 Leaves palmately angled or lobed Platanaceae, 454 



Leaves ovate or oblong, entire Leitneriaceae, 330 



Styles or long stigmas 2. 

 Fertile flowers 2 or 3 at each scale of the catkin Betulaceae, 332 

 Fertile flowers single under each scale; nutlets 



naked, waxy-coated, or drupe-like Mteicaoeae, 329 



¥. Flowers not in catkins b. 



b. Ovary or its cells containing only 1-2 (rarely 3-4) ovules u. 

 c. Pistils more than 1, distinct or nearly so. 



Stamens inserted on the calyx; leaves with stipules Eosaceae, 454 



Stamens inserted on the receptacle. 

 Leaves punctate with transparent dots Zanthoxylum, 537 



Leaves not dotted. 

 Calyx present, usually colored or petal-like Ranunculaceae, 392 

 Calyx none ; flowers spiked Pipbraobae, 320 



;;. Pistil 1, simple or compound d. 

 d. Ovary free from the calyx, which is sometimes wanting e. 

 e. Stipules (ocreae) sheathing the stem a+ the nodes. 



Tree ; calyx none Platanaceae, 454 



Herbs ; calyx present, commonly corolla-like Polygonaceab, 353 

 e. Stipules not sheathing the stem, or none /. 

 /. Herbs g. 

 g. Aquatic, submerged or nearly so. 



Leaves whorled, dissected; style 1 Ceratophtllaceae, 389 

 Leaves opposite, entire ; styles 2 ; ovary 4-celled 



CallitrichAceae, 549 

 g. Not aquatics h. 

 h. Styles 10 ; ovary and berry 10-celled Phytolaccaceae, 374 



h. Style, if any, and stigma 1. 



Flowers unisexual; ovary of the fertile flowers 



1-celled Urticaceae, 344 



Flowers perfect ; pod 2-celled, 2-seeded Lepidium, 425 



h. Styles 2-3 or branched ; ovary 1-4-eelled i. 



i. Leaves palmately lobed or divided Cannabineae, 344 



i. Leaves not palmately lobed or divided j. 

 j. Ovary and pod 3-celled ; juice usually milky. 



Flowers in basal spikes ; stamens 4 ; fila- 

 ments thick, flattened Buxaceae, 550 

 Inflorescence various, not of basal spikes; 

 stamens l-« , rarely 4 ; filaments not con- 

 spicuously thick EUPHORBIACEAB, 540 

 . j. Ovary not 3-celled ; juice not milky k. 



k. Flowers in numerous small involucrate 



heads ; fruit a .3-angled achene Briogonum, 35? 



k. Flowers not involucrate. 



Leaves covered at least beneath with stel- 

 late hairs; embryo straight Euphokbiaceae, 640 



