662 



TREES OF NORTH AMERICA 



of the St. Lawrence River to southern Ontario and westward to eastern North Dakota and 

 eastern and northeastern Iowa, and southward through the northern states and along the 

 Appalachian Mountains to northern Georgia and Mississippi; more abundant on the At- 

 lantic seaboard than in the region west of the Appalachian Mountains. 



Occasionally cultivated as an ornamental plant in the United States, and very commonly 

 in central and northern Europe. 



X Rhus hybrida Rehdr. a hybrid of R. iyphina and R. glabra L. has been found in Mas- 

 sachusetts. 



2. Rhus copallina L. Sumach. 



Leaves 6'-8' long, with a slender pubescent petiole and rachis more or less broadly 

 wing-margined between the leaflets, the wings increasing in width toward the apex of the 

 leaf, and 9-21 oblong or ovate-lanceolate leaflets entire or remotely serrate above the mid- 

 dle, sharp-pointed or rarely emarginate at apex, acute or obtuse and often unequal at 



Fig. 598 



base, those of the lower pairs short-petiolulate and smaller than those above the middle 

 of the leaf, the others sessile with the exception of the terminal leaflet sometimes con- 

 tracted into a long winged stalk, when they unfold dark green and slightly puberulous 

 above, especially along the midrib, and covered below with fine silvery white pubescence, 

 at maturity subcoriaceous, dark green and lustrous above, pale and pubescent below, 

 1|'-2|' long and about f wide, with slightly thickened re volute margins, a prominent mid- 

 rib and primary veins; turning in the autumn before falling dark rich maroon color on the 

 upper surface. Flowers appearing from June in the south to August in the north, those 

 of the staminate plant opening in succession during nearly a month and continuing to 

 unfold long after the petals of the pistillate plant have fallen, on stout pubescent pedicels 

 f '-j' long, in short compact pubescent panicles, the lower branches from the axils of the 

 upper leaves, 4'-6' long, 3'-4' broad, and usually smaller on the female than on the male 

 plant, their bracts and bractlets ovate or oblong, densely cinereo-pilose, deciduous before 

 the expansion of the flowers; calyx puberulous on the outer surface, w T ith ovate acute lobes 

 one third as long as the ovate greenish yellow petals rounded at apex, becoming reflexed 

 above the middle; disk red and conspicuous; stamens somewhat longer than the petals, 

 with slender filaments and large orange-colored anthers, in the pistillate flower much 

 shorter than the petals, with minute rudimentary anthers; ovary ovoid, pubescent, gla- 

 brous, much smaller in the staminate flower. Fruit ripening in five or six weeks and borne 

 in stout compact often nodding pubescent clusters sometimes persistent on the branches 



