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NOTES ON SOME NORTH AMERICAN 
SPECIES OF'pARMELIA. 
BY HENRY WILLEY. 
The large lichen genus I’annelia presents many difnculties from 
the variability of its forms, and Avith regard to the chemical reac¬ 
tions of the tJiallus with liquid potassa (K) and hypochlorite of 
lime (CaCl) either separately or combined. As Tuckerman has re¬ 
marked, it tends to develop into evernioid forms, of which the ex¬ 
treme is manifested in P. Kamtschadalis and P. cei-vicornis, and 
this tendency is manifested in species of the stock of P. perforata. 
Some writers have placed Evernia furfuraeea in Parinelia. As to 
the chemical relations I am unable to attach absolute specitic value 
to them. There are exceptions to their constancy, some of which 
w'ere pointed out b}’^ Tuckerman in a paper in the American Natu¬ 
ralist for 1868. 
It is possible that a lichen may possess difterent chemical constit¬ 
uents at different stages of growth, or under different conditions of 
soil, climate, etc. Experiment on the same plant at different peri¬ 
ods of its development is necessary to confirm the deductions from 
simple examination. Still, the reactions appear to be constant in 
most of the species of Parmelia and may serve as an aid in their de¬ 
termination, while the exceptions remain to be accounted for. 
Where there appears to be an exception we may best say that “per¬ 
haps’' the specimen belongs to a distinct species. 
Tuckerman, whose views in regard to species were very conserva¬ 
tive, described in his 8ynoj)sis nineteen species of Parmelia. Some 
of his varieties are regarded by other authors, either on chemical / 
or other grounds, as distinct species. Nylander, in Flora, 1885, p. 
605. described ten North American species, and has discovered some 
new ones among specimens sent him from New Bedford; and some 
ailditional species have turned up since Tuckerman wrote So that 
at present there appear to be known about forty species. The ^ 
reactions of most of the species are given in Hue's Lichenes Exotici. 
1. P. perlata (L,) Ach.—I’h. K 5 mllow Me. K—. But in 
the var. olivetorum Ach. (the proper designation of which seems to 
be olivaria Ach.) Me. K dull red. The lichen is a widely extended 
one. Very near to it is P. cetrarioides (Del.) Nyl., w-hich occurs on 
rocks in New Bedford, agreeing with a specimen from Switzerland 
(Lojka,). Another New Bedford specimen, with the habit and re¬ 
action of perlata, has the lobes ciliate, and may be the var. ciliata 
DC. But Nylauder considered this hardly to differ from P. crinita. 
A sorediate form (var. sored,iata Seiner.) also occurs in New Bed¬ 
ford. 
2. p. crinita Ach. —The New Bedford plant referred here 
in lVille 3 '’s Lichens of Neui Bedford is referred by Nylander to P. 
