VASCULAR PLANTS. 121 



Family lxxxviii. Plataneae. 



Monoecious. Flowers naked, capitulate on 

 globose receptacles. $ head: stamens go, 

 irregularly mingled with the scales. ? head : 

 ovaries oo, placed irregularly among scales. 

 Fruit a coriaceous nutlet. Leaves alternate, 

 palmately lobed. 



l. Platanus, L- 

 Only genus. Characters of the order. 



Family LXXXIX. Urticaceae. 



$ perigonium 5-lobed. Stamens 5; filaments 

 inflexed in aestivation; anthers introrse, 2-locu- 

 lar. Ovary rudimentary. ? perigonium 

 2 — 5-lobed. Ovary 1-locular, 1-ovulate. Fruit 

 an akene, sometimes baccate by the persistent 

 and succulent perigonium. Stipules generally 

 persistent. 



1. Urtica, Tournef. 



& perigonium regular and spreading. 

 9 perigonium 2-parted, with sessile, penicillate 

 stigma. 



© . 2f . covered with stinging hairs. 



2. Hesperocnide, Torrey. 



? perigonium gamophyllous, urceolate, 

 compressed, minutely dentate. 

 . weak and'slender. 

 6 



