FINK—THE LICHENS OF MINNESOTA. 198 
1. Parmelia perlata (L.) Ach. Meth. 216. 1803. Puate 35, 
Lichen perlatus L. Syst. Nat. ed. 12. 712. 1767. 
Thallus prostrate, the margins usually slightly ascendant, commonly orbicular in 
outline, the somewhat imbricated lobes rather large, with rounded undulate margins, 
these without cilia but frequently clothed with white soredia; pale or darker sea- 
green above, below black with brown margins and clothed here and there with black 
rhizoids; good-sized or sometimes very large, commonly 7.5 to 20 cm. in diameter, in 
extreme examples reaching 45 cm.; apothecia of middle size, 4 to 8 mm. in diameter, 
with chestnut disk and entire margin; spores ellipsoid, 10 to 17 ~ long and 6 to 10 4 
wide. 
Ours sterile and apothecia not seen. The above apothecial and spore characters 
are taken from Nylander. 
Found only in the northern portion of the State and rather infrequent. On rocks 
or more rarely on trees. 
Distributed throughout the northern United States, Alaska, and British America, 
especially in mountains. Known in all the grand divisions, but usually not extend- 
ing into extreme arctic regions. 
la. Parmelia perlata ciliata (Lam. & DC.) Schaer. Enum. Lich. Eur. 34. 1850. 
Lobaria perlata ciliata Lam. & DC. FI. Fr. ed. 3. 2: 403. 1805. 
Thallus lobes as above or frequently more dissected, their margins and sometimes 
the upper surface black-ciliate and the surface frequently. bearing soredia and isidi- 
oid growths. 
Ours more densely rhizoid-bearing below than the type. Sterile. 
A rare plant in the State, collected on Carlton Peak and at Rainy Lake City. On 
trees and mossy rocks. Also no. 362 from Gunflint referred to Parmelia crinita 
belongs here. 
Littie is known of the plant in America, but Nylander reports it from all of the 
grand divisions except Asia. 
2. Parmelia perforata (Wulf.) Ach. Meth. Lich. 217. 1803. 
Lichen perforatus Wulf. in Jacq. Coll, Bot. 1: 116. 1786. 
Thallus prostrate with ascendant margins, commonly orbicular in outline, the 
lobes rather large and somewhat imbricate, with rounded margins usually more or 
less crenate or irregular and ciliate, the upper surface sea-green or whitish and fre- 
quently rugose toward the center, beneath black or brownish black and usually 
brown toward the margin, bearing strong black rhizoids over the greater portion of the 
lower surface, usually large, 7.5 to 15 cm. in diameter; apothecia rather large, 2 to 
12 mm. in diameter, subpedicellate, with chestnut disk, this deeply concave or even 
cyathiform, commonly perforate at the center, the margin entire or crenate; hypo- 
thecium pale or slightly yellowish; hymenium colorless below and brownish just 
below the epithecium; paraphyses commonly simple and slender, the apex usually 
brownish and thickened; asci clavate; spores oblong-ellipsoid, 9 to 14 4 long and 6 to 
7.5 » wide. 
Collected at Taylors Falls on rocks and at Mankato on trees. A rare plant in Minne- 
sota, but doubtless distributed quite generally over the southern half of the State. 
The doubtful plant recorded from Carlton Peak belongs to the subspecies above, 
though, as Tuckerman remarks, it is “‘quite as much at home in the present species.” 
Widely distributed in North America and known in all the grand divisions except 
Asia. 
2a. Parmelia perforata hypotropa Nyl. Syn. Meth. Lich. 1: 378. 1858. 
Thallus rather light sea-green above and pale or slightly brownish below, where it 
is clothed with white or slightly colored rhizoids, the upper surface and the margins 
somewhat sorediate, the margins not ciliate. 
