124 Rhodora  . [JUNE 
have the pubescence of the leaves at least partly villous. It is, however, 
hardly advisable to consider these specimens as representing a distinct 
variety or form, as the villous character of the pubescence does not 
seem to be very constant; sometimes the lower leaves of a shoot show 
a distinctly villous pubescence, while in the upper leaves all the hairs 
are straight and appressed. In the herbarium of the Arnold Arboretum 
and in the Gray Herbarium I have noted the following specimens as 
having the leaves on the under surface at least partly villous. New- 
FOUNDLAND: St. John’s, Aug. 1, 1894, B. L. Robinson & H. Schrenck, 
No. 217; Lark Harbour, August 7, 1896, 4. C. Waghorne; Grand 
Lake, July 25-Aug. 15, 1906, Owen Bryant. QuvtEBEC: Roberval, 
Lake St. John, Aug. 22, 1895, J. G. Jack; Little Métis, July 17, 1906, 
James Fowler. ONTARIO: Kingston, Wolf Island, July 20, 1898, 
James Fowler. 
ARNOLD ARBORETUM. 
TWO NEW SPECIES OF UROMYCES ON CAREX. 
FRANK D. KERN. 
Tue number of American species of Uromyces on Carex is apparently 
small compared with the number of similar species of Puccinia. 
Up to the present time only four such species of Uromyces have been 
described while there are more than four times as many such species 
of Puccinia known. A preliminary study indicates that there occur 
some Uromyces forms which have been previously undetected. 
The Carex rusts have usually been considered especially difficult to 
distinguish and for that reason, perhaps, have not been so well studied 
or collected as the rusts of many other phanerogamic groups. There 
is a great similarity in the telial stages of these rusts and the failure to 
recognize properly the species may be the result of placing too much 
emphasis on the importance of this stage. Recent studies indicate 
that it is usually possible to find more distinctive morphological 
characters in the uredinia. Size of the urediniospores, color and 
thickness of walls, surface markings, and especially the number and 
arrangement of the germ-pores may all be taken into account. 
