134 
It has been thought to be a 7riodia, but it differs widely from 
any American species of that genus, in the compressed, zo¢ 
rounded flowering glumes, zo¢ three-lobed or three-toothed, in 
the lateral nerves zot hairy, and wot near the margin, in the 
shorter, nerveless empty glumes, the hairy rhachilla the crowded 
flowers, and in the middle fold of the narrow palet. 
It is hard to fix the relationship of this grass, but in the struc- 
ture of the flowers it seems to come nearest to Festuca, from 
which it differs in the flowers crowded on the rhachilla, in the 
one-nerved empty glumes, in the pointed or conical flowering 
glumes, not rounded on the back and only three-nerved. 
It appears to have been first collected by Bigelow on the 
Canadian River, and later (in 1873), by Messrs. Rothrock and 
Wolf, near Ft. Garland, Colorado. I name it for Mr. J. H. Red- 
field, the genial curator of the Herbarium of the Philadelphia 
Academy of Natural Sciences. : 
Note on a new North American Lichen. 
DERMATISCUM PORCELANUM, Nyl., n. sp. In the supple- 
ment to my “ Introduction,” etc., I ventured to describe a sin- 
gular plant from South Carolina as Buellia Catawbensis. Had I 
known that the plant had been sent to Dr. Nylander, before that 
sheet was printed, I should have withheld it. Dr. Nylander, ina 
letter to Prof. A. H. Green, who sent him specimens, gives the 
plant the name at the head of this article. Dermatiscum isa 
genus founded upon Exdocarpon Thunbergit, Ach. Syn., p. 101, 
a South African lichen. It is placed by Nylander, in his Synop- 
sis among the Lecanorei, just before Urceolaria. 
The description of Exdocarpon Thunbergit, Ach., is: ‘‘ Thallo 
crasso crustaceo-cartilagineo foliaceo orbiculari-repando peltato 
flavo-viridi subtus nudo nigro-fusco; ostiolis demum subglobosis 
atris.”” This, so far as the thallus is concerned, applies closely to 
our plant, excepting as regards color. But Acharius appears to 
have mistaken the character of the fruit. A description of the 
genus was given by Nylander in Mohl & de Bary’s Bot. Zeit., 
1867, p. 133. Ihave not seen it. Usbilicaria flavo-virescens, 
Leight., in Journ. Linn. Soc., 1869, pp. 33-35, is a Synonym of 
the African plant. . H. WILLEY. 
