450 THE PLANT LIFE OF MARYLAND 



LINACEAE. 



Linum virginianum L. Slender Yellow Flax. 



Throughout the state; in moist and dry situations; being most common 



in the Midland District. 

 Allegany County, near Cumberland (9GS). 



Linum medium (Planch.) Britton. Stiff Yellow Flax. 



Throughout the state; in moist open situations; being most common in 

 the Coastal Zone and apparently absent from the Upper Midland Dis- 

 trict and Mountain Zone. 



Worcester County, Herring creek (641). 



RUTACEAE. 



Ptelea trifoliata L. Hop Tree. 



Midland and Mountain Zones; in the deep soil of mountain slopes and in 



moist rocky slopes; infrequent. 

 Washington County, Round Top (707a). 



SIMARUBACEAE. 



Ailanthus glandulosa Desf. Ailanthus, Tree of Heaven. 



Commonly escaped from cultivation throughout the state. Naturalized 

 from Asia. 



POLYGALACEAE. 



Polygala lutea L. Orange Milkwort. 



Coastal Zone; in moist sandy situations; frequent. 

 Worcester County, Berlin (662). 



Polygala cruciata L. Cross-leaved Milkwort. 



Throughout the state; in moist sandy situations; frequent. 

 Cecil County, Hog Hills (370). 



Polygala verticillata L. Whorled Milkwort. 



Throughout the state; in forests and open situations; common. 



Polygala ambigua Xutt. Loose-spiked Milkwort. 



Throughout the state; in dry forests and open situations; common. 

 Cecil County, Elkton (371). 



Polygala incarnata L. Pink Milkwort. 



Coastal and Midland Zones; in dry open situations; infrequent. 

 Cecil County, Elkton (369). 



Polygala viridescens L. Purple Milkwort. 



Throughout the state in moist open situations; common. 

 Allegany County, near Cumberland (945). 



