A STUDY OF RHUS GLABRA 1 85 



This I designate as the type specimen. The other differs only 

 in having foliage of a clear and vivid green, and the stem shows 

 but little bloom. Both specimens have been presented to, and 

 will be preserved in, the U. S. National Herbarium. 



12. RHUS PETIOLATA, sp. nov. 



Branches not stout, glabrous, glaucous, striate, roughened 

 also by small and very protuberant lenticels : leaves ample, not 

 long, though long-petioled : leaflets about 13, large, 8-10 cm. 

 long, oblong-lanceolate and often subfalcate, distinctly petiolu- 

 late, the base obviously inequilateral, apex sharply acuminate, 

 the sides sharply but unevenly serrate, the serratures 13 to 15, 

 upper face of leaflets of a rich deep green, the lower very 

 glaucous : panicle small for the foliage, pyramidal, 10 cm. high, 

 compact, the branches thinly and rather stiffly hirtellous ; drupe- 

 lets rather large. 



Prairie region of the interior of Minnesota, the type from 

 near Spicer, Minn., August, 1892, W. D. Frost, Herb. Field 

 Mus. sheet No. 140259. Well marked by the large definitely 

 petiolulate leaflets. 



13. RHUS VALIDA, sp. nov. 



Branches very stout and robust, upright, at the end of the 

 first season no longer glaucous but light brown, between cin- 

 namon and chestnut-color, striate, copiously lenticellate : leaves 

 not large in proportion, less than 3 dm. long ; leaflets about 15, 

 approximate, short-petiolulate, oblong-lanceolate, 6-10 cm. 

 long, with about 11 serratures on each margin and a short tri- 

 angular-subulate point, texture subcoriaceous, upper face dull 

 deep green and transverse-rugose, lower fairly glaucous but 

 not white: panicle rather oblong-pyramidal, large, 12-14 cm * 

 high, its branches thinly tomentulose-pubescent : drupelets 

 many, large, little compressed, rather thinly plushy. 



Even in the herbarium specimens this impresses one as some- 

 thing wholly apart from any and all eastern and southern 

 shrubs that have been called R. glabra. The very stout stri- 

 ated, lenticellate and upright branches, with smallish foliage 



