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Synopsis describes'the European plant of that name, but the cited specimen 
from Louisiana as examined in his herbarium is not in accord with the 
description, nor is it in agreement with the beautiful and strongly differenti- 
ated tropical plant recognized by Wainio and others as P. laevigata . A 
plant of some similarity to both P. aurule 7 ita and P. laevigata is P. isi- 
diocera Nyl. Syn. p. 382. It is white within as in P. laevigata , is here and 
there isidiose particularly at the margins of the laciniae, the isidia being 
yellow within. The species is only known from Arctic America. 
P. endoxantha Merrill sp nov. 
Reaction K+ faint, C+ orange, K(C )1 orange. 
Thallus yellowish-glaucescent, moderately expanded, appressed, and 
somewhat adherent, irregularly orbicular, sub-membranaceous, laciniate, 
the laciniae confusedly imbricated, moderately divided, somewhat pinnately 
cleft, the axils both major and minor rounded, laciniae convex but plane at 
the. tips, borders sinuous, incised-crenate and retuse at the tips; destitute of 
soredia, or cilia; above opaque, commonly smooth but sometimes 
rugulose, or rarely and sparsely papillose-isidiose ; within pale or distinctly 
yellow ; below brown or black and moderately provided with short concolor- 
ons rhizinae. Apothecia centrally situated, appressed. small to medium, disk 
plane or slighly concave, chestnut or reddish-chestnut, with a thin rather 
erect crenate or annulate margin. Spores ellipsoid 10- n X 7 M, 8 in each 
thekb. 
On Palmetto logs in Hammock. Sanford, Florida, S. Rapp, July, 1907. 
Comparable with the European forms of P. tiliacea. but a more robust 
plant than are the American representatives of that species. P. endoxantha 
is irreconcilable with what Tuckerman designated as A*, tiliacea d. sulfurosa , 
for that form is likened to his b. sublaevigata , and furthermore it is said to 
be microphylline. P. x ant homy e la Nyl a European species provided with a 
yellow medulla is comparable with A. laevigata , and its nearest American 
affinity is P. aurulenta. Tuckerman says of the Parmelia species with a 
yellow medulla that “ It appears impossible in any large view whether of P. 
sulfurata, P. aurulenta or P. tiliacea sulfurosa to assign any other than a 
subordinate value of the modifications in these lichens of the medullary 
color.” Such an opinion might be assented to if the medullary color consti- 
tuted the only factor of difference, but in each of the several species here 
described other and piarked elements of diverseness help to dissociate the 
plants and confirm specific identity. 
P. oiivacea var. multisporum (Schneider) Merrill comb. nov. 
P. multisporum Schneider. Guide, p. 254. 
Reaction. Not affected by either K or C. 
Thallus olivaceous or brown, small, appressed, rather adherent, orbicu- 
lar when space occupied permits, submembranaceous, lobate-laciniate, 
moderately divided, narrowed and confusedly-imbricate centrally, usually 
platypliylline at the circumference, borders sinuous but crenate at the tips; 
typically without soredia, cilia, or isidia; above opaque or sub-shining, smooth 
