1899] Fernald, — Plants of the Crowfoot family 49 
specimen collected in 1829 by J. W. Robbins, on rocky ledges in 
Castleton, Vermont. Robbins’s plant was described in a few words by 
Oakes as Anemone cylindrica, var. alba. Later, however, Wood pub- 
lished the same plant as A. virginiana, var. alba. It has not been 
generally recognized as a noteworthy form of either species, except 
perhaps by Professor Peck, who has recently revived Wood's varietal 
name for a plant “common in the hilly parts of Sullivan county [New 
York], where it is the prevailing form.”* Other specimens of the 
plant have been referred, some to A. cylindrica, some to A. virginiana, 
while the New Brunswick specimens have been hesitantly placed at 
different times under both species. 
Observations in the field and study of herbarium specimens show 
that, in some characters, the northern white-flowered plant is inter- 
mediate between Anemone cylindrica and A. virginiana. In its large 
clear-white flowers this plant is quite different from the ordinary forms 
of either of those species with their thick greenish sepals. They do 
not differ, however, from exceptional specimens with white petaloid 
sepals of A. virginiana. In general habit the plant suggests the latter 
species, but it is decidedly more slender and graceful and usually more 
glabrate ; and the thin cuneate leaf-segments are much more coarsely 
and sharply toothed above than are the thickish ovate segments of 4. 
virginiana. Like that species, but unlike most A. cylindrica, the 
peduncles of the northern plant are commonly proliferous. The fruit- 
ing heads, on the other hand, are not unlike short heads of A. cy/in- 
drica ; but from well-developed heads of that species they are readily 
distinguished. A series of measurements from herbarium material 
brings out very well some of the differences in the heads of these three 
plants : — 
Average length. Average thickness. 
Anemone virginiana (22 heads) 18.25 mm. 13-35 mm. 
A. sp. (18 heads) ' 16.85 mm. 9.45 mm. 
A. cylindrica (30 heads) 30.45 mm. 8.00 mm. 
In the length of the head, then, 4. cy/indrica much exceeds both 
the others, while in thickness of the head both that species and the 
plant of the northern river-banks are greatly exceeded by 4. virginiana. 
In another character the head of the white-flowered species is more 
like that of A. cylindrica than of A. virginiana : while in A. virginiana 
the persistent styles are spreading, giving the head an echinate appear- 
1 Peck, 47th Ann. Rep. 27. 
