354 MACKENZIE: NOTES ON CAREX—XIII 
Very recently Wiegand * again called attention to certain of 
the points of difference between the two plants of Bicknell, and 
in a miraculous nomenclatural shuffle was able to apply the in- 
valid name Carex xanthocarpa as a varietal name under Carex 
annectens, 
One of the groups very well represented in the great collec- 
tion of local material at the Philadelphia Academy of Natural 
Sciences is the present one, and this collection has helped greatly 
in the rresent study. Carex annectens, as stated by Wiegand, 
turns out to be a plant principally of the Atlantic seaboard, 
extending from central Maine to North Carolina. It is a species 
of sterile soils and is often abundant in poor pastures or old 
fields. It gets up along the rivers and occurs sparingly in the 
Great Lake region and occasionally elsewhere in the interior, 
but it certainly very rapidly disappears as one gets away from 
the coastal plain. Carex xanthocarpa Bicknell, on the other 
hand, turns out to be a very widely distributed species. It is 
apparently a southern species which is pushing: northward. 
On the Atlantic seaboard it has reached as far north and east 
as Maine and central New York, and in the Mississippi Valley 
as far as Ohio and Illinois. It is more largely a plant of lime- 
stone regions, but both it and Carex annectens are weedy plants 
and are probably to a considerable extent introduced in pastures. 
The abundant material of Carex annectens and Carex xan- 
thocarpa Bicknell now before me has disclosed that these plants 
can be distinguished not only by the characters brought out by 
Bicknell but also by characters taken from the mouth of the 
sheath and the ligule of the upper leaves. In Carex annectens 
the ventral prolongation of the sheath at its mouth is high convex 
and about as long as wide, even in the upper leaves. This is 
well brought out in Boott’s plate 406. On the other hand, in 
Carex xanthocarpa Bicknell, the sheaths of the upper leaves are 
almost invariably truncate or low-concave at mouth and the 
prolongation, if any, is very much wider than long. 
In Carex annectens the ligule is also as a rule much less 
developed than it is in Carex xanthocarpa. As pointed out by 
Bicknell and Wiegand, Carex annectens at maturity has a dull 
yellowish look and the heads have a markedly echinate appear- 
*Rhodora 24: 73, 74. 1922. 
