(273) 



1. Platanus L- Sycamore. 

 Only genus. — ^<? . 

 1. P. RACEMOSA Niitt. — Common. Spring. 



Family 2. URTICACE^. 



6 perigonium 4-lobecl; stamens 4; fila- 

 ments inflexed in aestivation; anthers introrse, 

 2-cellecl; ovary rudimentary. ? perigonium 

 2 to 4-lobed; ovary 1-celled, 1-ovulate; fruit 

 an akene, sometimes baccate by the persistent 

 and succulent perigonium. Stipules generally 

 persistent. 



1. Urtica Tourn. Nettle. 



$ perigonium regular and spreading. ? 

 perigonium 2-parted, with sessile, penicillate 

 stigma. Herbs covered with stinging hairs. 



1. U. HOLOSERICEA Nutt. Inflorescence uni- 

 sexual; petioles short, stout. — IC- Common. 

 Summer. 



2. U. Lyallii Watson. Inflorescence uni- 

 sexual; petioles long, slender. — 1^. Marin 

 County. Summer. 



3. U. URENS L. Inflorescence androgynous. 

 0. Cultivated lands. Spring. 



Introduced from Kurope. 



2. Hesperocnide Torr. 

 ? perigonium gamophyllous, urceolate, com- 

 pressed, minutely dentate. — 0. 

 12a 



