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mistaken for that plant. The lobes are broader than in the other Parmelia 
species with a colored medulla. P. immiscens Nyl. Flora, 1885. p. 606, is 
somewhat similar to the present. The medulla is yellow or sometimes white, 
apothecia crowded, spores small, and the reaction is distinctly K+ for the 
medulla. 
P. persulfurata Nyl. in Flora, 1885, p. 606. 
Reaction Kt, C~. 
Thallus ochroleucous, greenish or yellowish-green, somewhat expanded in 
old plants, loosely attached, irregularly orbicular, membranaceous-cartilagin- 
eous, lobate, the lobes moderately divided, axils acute, and of medium width, 
irregularly radiant, contiguous and subimbricate, confusedly plicate and 
sometimes subcoalescent centrally, where also more or less exasperate- 
lobulate, borders of the major divisions crenate, decurved or sub-ascendant, 
but appressed and plane at the tips, the lobuli both ascendant and depressed 
with the margins rather incised-crenate, sparsely sub sorediate on the 
borders of the lobes, the margins somewhat isidiose, likewise the surface of 
the thallus sparingly, and the margins of the lobuli copiously; above opaque 
and interruptedly rugulose; within distinctly sulfureous; below exactly as 
in P. sulfur at a. Apothecia not seen. 
On trunks in tropical forest. 
Examined from Sanford, Florida, S. Rapp. Reported from Louisiana, 
Mexico and Cuba. 
Crombie states that Tuckerman failed to distingished this species from 
P. sulfur ata, but the plants are absolutely unlike in color and in some other 
particulars as a comparison of the descriptions will show. 
P. AURULENTA Tuck. Suppl. I, p. 424. 
Reaction K+, C+ orange. 
Thallus glaucous, glaucescent or ashy-glaucescent, moderate in size, 
orbicular, loosely attached, submembranaceous, laciniate, variably divided, 
the axils rounded, laciniae subimbricate, borders sinuous or crenate, tips 
retuse or markedly incised-crenate, in typical states displaying sub-margin- 
ally, exasperate, rounded or sometimes confluent sub-isidiose soredia, but 
other conditions observed that are merely papillose-isidiose ; above rugulose 
and opaque; within yellowish; below black except narrowly brownish at the 
margins, with concolorous rather abundant short rhizinae. Apothecia 
medium, short-pedicelled, cup-shaped, disk pale-chestnut or darker, with a 
distinctly tuberculate-crenate inflexed margin, the exciple papillose-isidiose j 
isidio-sorediate, or at times smooth. Spores ellipsoid 9-17 X 4-7//. 
On trunks of trees and on rocks. 
Examined from Ottawa, Ontario, J. Macoun; from the vicinity of Balti- 
more, Maryland, C. C. Plitt. Reported from various Eastern States and from 
Newfoundland, but apparently not found in the West. 
The configuration of the laciniae, rounded axils, and black rhizinose 
under surface serve to ally this species with P. laevigata of Europe, but its 
distinctness is now admitted on all hands. P. laevigata of Tuckerman’s 
