PLANE TREE FAMILY. 389 



9. BROUSSONETIA, rAPEll MULBEIIIIY. (Named for P. N. V. 

 liroH.^soiict, a French herbalist.) 



B. papyri fera, Vent. Cult, as a shade tree from N. Y., S.; s))reading 

 by suckers, with a very fibrous bark ; leaves rough above, downy beneath, 

 serrate, some of them ovate or slightly heart-shaped, others 3-cleft or 

 variously lobed ; tiowering in spring. Japan and adjacent regions. 



10. URTICA, NETTLE. (The classical Latin name.) Common in 

 waste grounds and near dwellings ; flowers summer. 



* Flower clusters in branching panicled spikes ; often dioecions. 2/ 



U. gracilis, Ait. Fence rows, etc., common ; 2°-G° high, with ovate- 

 lanceolate, serrate leaves, long petioles, rather few stings, and slender 

 spikes. 



U. d/olca, Linn. A weed from Eu., full of stings, 2°-3° high, with 

 heart-ovate more deeply serrate leaves, downy beneath and shorter petioles. 



* » Flower clusters shorter than the petiole, mostly 2 in the same axil, 

 containing both sorts of flowers ; slings scattered. 



U. Orens, Linn. Weed from Eu., not common ; 8'-12' high, with ovate 

 leaves deeply cut into long spreading teeth ; flower clusters small, loose ; 

 stings few. 



U. chamaedryoides, Pursh. Slender, with heart-ovate or lance-ovate 

 leaves moderately tootlied, and dense flower clusters ; stings sparse. Ky., S. 



11. LAPORTEA, WOOD NETTLE. (Named for ilf. iaporte.) 1^ 



L. Canadensis, Gaud. Moist and rich woods ; 2°-o° high ; ovate 

 leaves i'-T long and long-pelioled, a single 2-cleft stipule in the axil ; 

 flowers all summer. 



12. BCEHMERIA, FALSE NETTLE. (Named for Frof G. F. Buh- 

 mer of Germany.) 11 



B. cylindrica, Willd. JNIoist shady grounds, 1*^-3° high, smoothish ; 

 leaves mostly opposite, ovate or lance-ovate, 3-nerved, serrate, long-peti- 

 oled ; flower-clusters crowded in long narrow interrupted spikes, in summer. 



B. nivea, Gaud. Kamie, or the Grass-Cloth Plant of China ; .3°-4° 

 high, with ovate leaves white-downy beneath ; planted S. for its valuable 

 textile fibers. 



13. PARIETARIA, PELLITORY. (Latin, from its habit of growing 



on walls.) 



P. Pennsylvdnica, Muhl. Low, only sparingly branched, or simple, 

 minutely downy ; leaves thin and veiny, roughish with opaciue dots, 

 oblong-lanceolate. Shady places, Mass., W. and S. 



CVI. PLATANACE^, TLANE TREE FAMILY. 



This small order consists merely of the genus 



1. PLATANUS, PLANE TREE. (The ancient name of the Oriental 

 .species, from the Greek word for broad, alluding either to the leaves 

 or the wide-spreading branches.) Flowers moncecious, in separate 

 naked heads hanging on slender peduncles ; the sterile of many short 

 stamens with club-shaped little scales intermixed ; the fertile of club- 



