NORMAL JIMSON WEED 



Pot-grown normal plant shown for comparison with other plants. (Fig. 7.) 



third line : " Cockelbur " with small nar- 

 tow capsules; "Mutilated," two cap- 

 sules, the one on left showing the usual 

 mutilated condition of apex suggesting 

 the name; and "Ilex" with small cap- 

 sules and slender spines. On the fourth 

 line "Tobacco-leaf" with small cap- 

 sules and short stout spines ; ' ' Micro- 

 carpic" with small, rather downy cap- 

 sules; "Buckhng," a type related to 

 " Microcarpic " but with larger more 

 ovate capsules; and lastly an unnamed 

 type not yet investigated. 



Habit and leaf characters can best 

 be shown by photographs of pot and 

 field plants. A few selected mutations 

 will be briefly described and illustrated 

 by the accompanying photographs. 



Polycarpic (Fig. 8). — The habit and 

 leaf character of the mutant "Poly- 

 carpic" shown in Fig. 8 is strikingly 

 different from the normal plant shown 

 as a _ control in Fig. 7. The most 

 conspicuous peculiarities are its narrow 

 entire leaves and its slow growth. The 

 name was given on account of the 

 114 



frequent presence of extra abortive car- 

 pels within the flower. 



Globe (Fig. 9 and 10).— The "Globe" 

 mutation was the first to be discovered, 

 perhaps because it is one of the most 

 distinct of the variant forms and shows 

 in less degree than most of the mutants 

 the lack of vigor seemingly character- 

 istic of abnormal types in this as in 

 other species. It was named on ac- 

 count of the depressed globose capsules 

 already illustrated. The leaves are 

 broader and less indented than normals 

 and the foliage tends to be more com- 

 pactly massed at the ends of branches. 

 "Globe" mutants are recognizable at 

 an early stage, frequently at or before 

 the opening of the second leaves. Fig. 

 10 shows at the left a typical "Globe" 

 seedling which, with its broader entire 

 leaves is easily distinguished from the 

 normal plant of the same age beside it. 



Cocklehur{¥{g.n2ind 12).— The" Cock- 

 lebur" mutant was so called because 

 of the small, narrow capsules already 

 illustrated. It was first recognized as 



