Plelea. RUTACE.E. 9 



its greatest development in southern Arkansas, Louisiana, and eastern 

 Texas. A shrubby, or on the coast arborescent, form of western Texas, 

 with shorter ovate leaves, is var. fruticosum, Gray. 



Wood light, hard, not strong, soft, coarse-grained, not durable, con- 

 taining many scattered open ducts ; medullary rays numerous, thin ; 

 color light brown, the sap-wood lighter. 



24. Xanthoxylum Caribseum, Lam. 

 Satin-wood. 



Keys of semi-tropical Florida ; in the West Indies. 



A small tree, 6 to 10 metres in height, with a trunk 0.30 to 0.40 metre 

 in diameter ; not common. 



Wood very heavy, exceedingly hard, not strong, brittle, fine-grained, 

 compact, satiny, susceptible of a beautiful polish ; medullary rays numer- 

 ous, thin, conspicuous ; color light orange, the sap-wood lighter. 



25. Xanthoxylum Pterota, HBK. 



Wild Lime. 



Semi-tropical Florida, — Mosquito Inlet to the southern keys, and on 

 the west coast from about latitude 29° to Cape Sable ; southwestern 

 Texas ; and southward through Mexico to Brazil. 



A small tree, sometimes 8 metres in height, with a trunk rarely ex- 

 ceeding 0.15 metre in diameter, or often reduced to a slender shrub. In 

 Florida common, and reaching its greatest development on the keys of the 

 west coast ; in Texas not common, but widely distributed as a small shrub, 

 or. on the shores of Matagorda Bay, west of the Nueces River, and in the 

 valley of the Bio Grande, a low tree. 



Wood heavy, hard, close-grained, compact ; medullary rays thin, nu- 

 merous ; color brown tinged with red, the sap-wood yellow. 



26. Ptelea trifoliata, L. 



Hop Tree. Shrubby Trefoil. Wafer Ask. 



Banks of the Niagara River, and Pennsylvania southward to northern 

 Florida, west to Minnesota and the Indian Territory ; through western 

 Texas to New Mexico ; in northern Mexico. 



A small tree, sometimes 4 to 6 metres in height, with a trunk 0.15 to 

 0.20 metre in diameter, or more often reduced to a slender shrub ; shady, 

 rocky hillsides. 



A variety with more or less pubescent leaves, not rare on the south 

 Atlantic coast, and the common form of western Texas, is var. mollis, 

 Torr. & Gray. 



Wood heavy, hard, close-grained, compact, satiny, layers of annual 

 growth clearly marked by two or three rows of open ducts ; medullary 

 rays few, thin ; color yellow-brown, the sap-wood hardly distinguishable. 



