FINK—THE LICHENS OF MINNESOTA, 161 
mm. long and frequently as wide at the anterior end so that they become roughly equi- 
lateral; apothecia along the margins, usually the anterior margin, superficial and 
rounded, with entire or crenulate, thalloid, but commonly brown and apparently biato- 
roid exciple, horizontal with flat brown to blackish disk, middle-sized, 2 to 5 mm. in 
diameter; hypothecium brown or brownish; hymenium pale or brownish below and 
darker above; paraphyses simple or rarely branched, enlarged and brownish toward 
the apex; asci cylindrico-clavate; spores fusiform, frequently pale brown, 28 to 45 p 
long and 6 to 9 » wide, but rarely longer, and 5-celled instead of 4-celled in ours. 
Collected at Grand Portage and at South Fowl Lake. On earth and mossy rock; 
a rare plant in Minnesota. 
Widely distributed in the northern portion of the United States, especially in 
mountainous country, and common northward to arctic America. Known also in 
Europe and Asia. 
3. Peltigera horizontalis (L..) Hoffm. Deutsch. FJ. 2: 107. 1795. 
Lichen horizontalis L. Mant. Pl. 2: 132. 1771. 
Thallus somewhat closely attached to the substratum, but the margins of the lobes 
more or less ascending, middle-sized or larger, 6 to 19.5 cm. in diameter, the upper 
surface usually smooth and shining and devoid of trichomatic hyphe, the margins of 
the wide lobes rounded and entire, undulate, or variously irregular, sea-green vary- 
ing toward ashy brown, or reddish brown, below bearing large rhizoids commonly 
dark in color and smaller ones of the same colors, the latter forming a close nap, 
the nap and larger rhizoids usually lighter-colored toward the margin; veins not con- 
spicuous in ours; apothecia on somewhat narrowed lobes, submarginal and frequently 
superficial, middle-sized, 3 to 5 mm. in diameter, transversely oblong, commonly 
flat, the disk reddish brown; hypothecium commonly brownish; hymenium pale, or 
brownish above; paraphyses simple or rather rarely branched, usually enlarged and 
brownish toward the apex; asci cylindrico-clavate; spores 4-celled, 30 to 48 » long 
and 5.5 to 8 » wide. 
Distributed throughout the northern portion of the State. On earth in swamps 
and rarely over mossy rocks. 
The plant is widely distributed in North America. Known also in Europe and 
Africa. 
4. Peltigera polydactyla (Neck.) Hoffm. Deutsch. Fl. 2: 106. 1795. 
Lichen polydactylon Neck. Meth. Musc. 85. 1771. 
Thallus attached much as in the last and of about the same size, likewise having 
ascending lobes and smooth, shining upper surface devoid of trichomatic hyphe, 
the margins of the lobes much as in the last, except those bearing apothecia, these 
usually digitately clustered and more elongated, sea-green, lead-colored, or rarely 
becoming brownish, below bearing rhizoids as in the last, but on the whole lighter- 
colored, reticulated with commonly brown or darker veins and not conspicuously 
covered with nap, lighter toward the margin; apothecia middle-sized, 3 to 5 mm. in 
diameter, rounded or more commonly revolute, the disk reddish brown; hypothecium 
commonly brownish; hymenium pale, or brownish above; paraphyses simple or 
rarely branched, commonly thickened and brownish toward the apex; asci clavate or 
cylindrico-clavate; spores 4 to 8-celled, 60 to 100 » long and 3 to 4 » wide. 
This species and the last are very difficult to distinguish macroscopically, but the 
spore characters are perfectly distinct. 
Confined to the northern portion of the State, a single specimen recorded from 
Minneapolis being doubtful. On earth, especially in swamps. 
Generally distributed throughout North America. Known in all of the grand 
divisions. 
