28 
rubra. By most recent authors the latter has been regarded as a 
‘variety of the former, but this view has been ably attacked by 
Prof. George Lawson in a paper on “Remarks on the Distinctive 
-Characters of the Canadian Spruces,” published, I think, in 1888. 
‘He there maintains that the Red Spruce is distinct from the 
Black, and I am in entire accord with this opinion. The White 
Spruce is very different from either of the others by its elongated 
cones, entirely glabrous and glaucous twigs and sterigmata, and 
very light green leaves. P. rubra differs from P. Mariana by its 
very slender twigs, which are sparingly pubescent, the sterigmata 
nearly or quite: glabrous, its very slender light-green, nearly 
straight, very acute leaves, and its oblong cones, which are decid- 
uous at the end of the season, the scales lacerate or 2-lobed. P? 
Mariana has stout, very pubescent twigs and sterigmata, stout 
and thick, merely mucronate, dark green, incurved leaves, and 
ovate, larger cones, which are persistent for two or more years, 
their scales entire or merely erose. P. rubra, according to my ob- 
servations, reaches a much greater altitude on McIntyre than 
does P. Mariana, and this agrees with our collections in the Blue 
Ridge of Virginia. The very slender twigs of P. ruéra and its 
light green leaves give it a much more graceful aspect than is 
exhibited by P. Mariana. 
CYPERUS RIVULARIS Kunth, Enum. 2: 6 (1837). 
Cyperus diandrus var. (?) castaneus Torr. Ann. Lyc. N. Y. 3:. 
252 (1836). 
Having recently had occasion to reéxamine certain species of 
the genus Cyperus, in view of the publication of the new List of 
Northeastern American plants, prepared for the Botanical Club of 
the American Association for the Advancement of Science, I con-. 
clude that this plant is specifically distinct from C. diandrus, Torr- 
I am strengthened in this view by a note received from Mr. 
Coville in May, 1890, in which he emphasizes the characters ad- 
duced by Torrey in 1836. These are concisely as follows : 
 C. rvularis: Scales of the spikelets firm, smooth, shining; , 
styles not at all or scarcely exserted. : 
C. diandrus: Scales membranaceous, usually slightly wrinkled 
dull; styles conspicuously exserted.. 
