TRbooora 
JOURNAL OF 
THE NEW ENGLAND BOTANICAL CLUB 
Vol. 16. December, 1914. No. 192. 
NOTES ON THE FLORA OF MARYLAND AND 
VIRGINIA,— II. 
Ivar TIDESTROM. 
FIvE species of poplars are listed for Maryland in a recent work.! 
In a booklet? covering a part of the Amentiferae (Salicaceae, Cerif- 
erae, and Betulaceae) nine species were listed, of which five have been 
introduced and four are native. It is to be noted that Elysium 
Marianum purports to include Virginia also, but since all of the spe- 
cles are found within the limits of Maryland, the wide difference 
between the accounts of the poplars from the latter state should not 
be passed over without some explanation. The lists given in Plant 
Life of Maryland include the following species: Populus alba, P. 
heterophylla, P. grandidentata, P. tremuloides, and P. dilatata. 
Populus alba is found escaped in many places throughout the 
region, as is also the closely related P. canescens. The two species are 
readily distinguished both by the flowers and the leaves. The follow- 
ing diagnoses are given of the staminate aments of the two species: 
P. ALBA. Stam. aments fullgrown, 8-10 cm. long, 1.5 em. in 
diameter: subtending floral bracts villous, rounded with a cuneate 
base; light brown, 6 mm. long (incl. the stipe), 3 mm. wide, laciniately 
cleft into 5 or more teeth: staminiferous disk (on a stalk 1 mm. long) 
elliptic, about 2 mm. long, 1.5 mm. wide: stamens about 8; anthers 
red, 0.7 mm. long: pollen-grains spherical, almost smooth. 
P. CANESCENS. Stam. aments fullgrown, about 9 cm. long, 2 cm. 
in diameter: subtending floral bracts villous, rounded with a cuneate 
base, russet brown, 4 mm. broad, 7 mm. long (incl. the whitish stipe), 
! Plant Life of Maryland, p. 422. 
? Elysium Marianum 3: 11, 1910. 
