MUTANTS AND HYBRIDS OF THE OENOTHERAS. II 



After an examination of material in the field in America in the 

 summer of 1904, Professor De Vries informs the authors that the 

 O. biennis used in his breeding experiments at Amsterdam differs from 

 the foregoing, and is to be included with a form usually termed 

 O. biennis grandiflora by collectors. The exact relationship of the 

 two has not yet been carefully determined. 



ONAGRA ARGILLICOLA MACKENZIE. 



Within the last year a new wild species of evening-primrose has 

 been brought to notice from the mountains of Virginia and West Vir- 

 ginia, being described by Mr. K. K. MacKenzie as " one of the most 

 noticeable and common plants on the line of the Chesapeake and Ohio 

 Railroad on both sides of the boundary line between Virginia and 

 West Virginia." It has also been collected by Mrs. L. F. Ward, at 

 "Alleghany," W. Va., and by Mr. and Mrs. E. S. Steele at Sweet 

 Springs, W. Va., and the cultures in the New York Botanical Garden 

 were begun with seeds from the latter locality. The following descrip- 

 tion has been compiled from observations on living plants of the 

 resultant cultures : 



Seedling about two months old. Leaves minutely pubescent, copi- 

 ously so near the base ; blades oblong or elliptic-oblong, the larger 

 ones less than i cm. wide, obtuse, each gradually narrowed into a 

 copiously pubescent petiole. 



Seedling Jive months old. Rosette relatively lax ; leaves minutely 

 pubescent; blades spatulate to narrowly linear-spatulate, the larger 

 ones over 25 cm. long, 2 to 2.5 cm. wide, repand, more distantly so 

 and with more pronounced teeth near the base, each gradually nar- 

 rowed into a long petiole. 



Mature rosette. Leaves numerous and conspicuously elongated ; 

 glabrous, or nearly so, except the sparingly ciliate margins, the larger 

 ones over 40 cm. long, 2 to 2.5 cm. wide; blades broadly linear to 

 linear-spatulate, sinuate, the teeth slightly more pronounced near the 

 base; petioles relatively stout. 



Adult plant. Plant rather luxuriant, depressed in habit. Stems 

 suppressed or very short, the branches radiate, decumbent, not chan- 

 nelled, somewhat tortuous, mainly 6 to 12 dm. long, puberulent and 

 pubescent, with few spreading or ascending hairs ; leaves very numerous, 

 10 to 15 cm. long on the lower part of the branches ; blades undulate, 

 or repand-denticulate, those on the lower part of the branches broadly 

 linear to narrowly linear-oblong, acute or short-acuminate, each nar- 

 rowed into a semi-terete petiole, those of the upper cauline leaves 

 similar to those of the lower, but relatively shorter and broader, and 



