176 



GREENE 



Rhus glabra Linn. Sp. PL, p. 265. 1753, in part, excluding 



both the shrub of C. Bauhin and that of Catesby. 

 Rhus glabrum, Mill. Diet. 1768? 



Shrub commonly 2-3 m. high, with very few and stout diver- 

 gent branches: leaves mostly 5-7 dm. long, the rachis and 

 petiole very stout, the latter 1-1.5 dm. long; leaflets about 

 17-21, not crowded, very large, 8-13 cm. long, 3-3.5 cm. wide, 

 oblong-lanceolate, subsessile, abruptly and not slenderly acumi- 

 nate, evenly serrate, the serratures 12 or 13 on a side, texture 

 in maturity rather firm but not subcoriaceous, upper face deep 

 green and smooth, lower face glaucous but not excessively so : 

 staminate panicle very large, often 3 dm. high, pyramidal, 

 almost 2 dm. wide at base in the largest, the pistillate, when in 

 flower nearly as long but fusiform, less than 1 dm. wide up and 

 down the middle part, in fruit oblong-fusiform, 6-10 cm. wide 

 below the middle ; drupelets very many, round-ovate. 



This is the common and apparently the only glabrous Rhus 

 of the Potomac Valley in southern Maryland and eastern Vir- 

 ginia, ranging eastward and northward through southern 

 Pennsylvania, to Delaware, New Jersey, and to Connecticut, if 

 I refer here a flowering specimen in the National Herbarium 

 from Green's Farms, 1894, by C. L. Pollard. The type from 

 which the above description is drawn is the shrub as it grows in 

 the District of Columbia, and up and down the Potomac above 

 Georgetown. 



The choice between this and the next for something to bear 

 the name R. glabra Linn, is made rather arbitrarily, perhaps ; 

 for either one may have been that grown in the Eltham garden 

 and figured by Dillenius. The two are distinct by their fruiting 

 panicles, and the fruit of the Dillenian type was unknown, 

 because only the staminate shrub was raised from the seed by 

 which it was introduced into Europe. As to the size of the 

 leaves and leaflets, however, the present species alone answers 

 to the account given by Dillenius ; hence the probability in favor 

 of this as identical with his. 



Since Linnaeus himself did not describe the species ; and 

 since the one only synonym, quoted by him which carries with 

 it a description is that of Dillenius, the name R. glabra must be 



