104 MIDLAND NATURALIST. 
pect quite thin and spare, because the foliage is remarkably small 
and far apart, and the flowering branches are equally remote, and 
are almost horizontally spreading. Thus what one must techni- 
cally denominate the panicle of 7. polygmum is sometimes a yard 
high and almost two feet wide, and so loose and open as seem no 
panicle at all. At an opposite extreme from this is the small con- 
gested panicle of 7: vegetum, while its yard high stem is closely in- 
vested with ample leaves, the single leaflets about two inches long 
and very broad. On such very marked vegetative differences alone, 
in default of other characters, the two species would be held distinct, 
à without need of mentioning that the southeastern plant is glabrous, 
the northwestern one pubescent. But while the stamens of all East- 
ern 7. polygamum consist of a firmly upright clavate filament and a 
very short merely oval anther, those of 7. vegetum have filaments 
which are capillary and therefore pendulous, the anthers being thin- 
ner, and of four times the length of those of the eastern ally. 
'The pubescence of this plant of North Dakota, extending as it 
does to the calyx, and even to the carpels, might cause one to ques- 
tion whether this might not be the long neglected and forgotten 7. 
dasycarpum. This particular species has been recently a subject of 
careful field study by me in its native wilds; for it is plentiful in 
southern Michigan and far eastward into Ontario, where it seems to 
take the place of the real 7. polygamum of the Middle States. 
Though a small plant compared with that, 7. dusycarpum has the 
floral characters not at all of the northwestern 7. vegetum, but of 
T. polygamum; that is to say, its filaments are clavate and erect and 
bear short oval anthers, all as in the southeastern species, from 
which it is distinguished as well by its different habitat and small 
size, as by its pubescent foliage, pilose pedicels and sepals, and more 
or less hairy carpels. 
Though truly and thoroughly akin to 7. polygamum there is 
nothing in the specimens of 7. vegetum that are before me to indi- 
‘cate that the species is other than dioicous; but further observation 
in the future may possibly reveal it as more or less polygamous. 
Washington, D. C. 
