A new variety of Carex lupulina 
EaArL E. SHERFF 
(WITH PLATE 26) 
In the summer of 1909, the writer’s attention was attracted 
by some peculiar sedges growing in a small stretch of swamp east 
of Thread Lake, at Flint, Michigan. In most respects they re- 
sembled Carex lupulina Muhl., but differed from the species proper 
in having white-margined leaves (including bracts) and scales and 
white-striped perigynia. - Muhlenberg,* in his original description 
of Carex lupulina, makes no mention of this form. 
At first a pathological cause was suspected of producing the 
peculiar color design. Typical Carex lupulina growing inter- 
spersed with the form was studied, and in no case was the color 
found to vary toward that of the form. Likewise, a study of 
many specimens of the form failed to show an intermediate stage 
between its color and that of the species. And further, where the 
stolons of both crossed and intertwined with each other, it was 
found that plants from any individual stolon or system of stolons 
were uniformly either all of the form or all of the species proper. 
In other words, the two were sharply distinct. Had the cause been 
pathological, it is not improbable that cases would have occurred 
in which the cause was but weakly operative and the demar- 
cation hence less distinct. Especially would an intermediate stage 
be expected in the young plants vegetatively produced by stolons 
and established some distance from the parent plants. Such 
intermediate stages being absent, it thus appears certain that we 
have to deal with a definite, fixed form and not with a temporary 
form induced by some obscure pathological factor. 
Unfortunately, material had scarcely been gathered for speci- 
mens when the level of Thread Lake was raised several feet by 
the reconstruction of the dam at its outlet, extending the lake 
back over and flooding the area occupied by the sedges. This 
* Miihlenberg ex Willd. Sp. Pl. 4: 266. 1805; Schkuhr, Riedgr. 2: 54. t. Ddd. 
fi 123 & t. Ji. 7.104. 1806. 
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