FINK—THE LICHENS OF MINNESOTA. 225 
Thallus usually brownish, with scarcely ascending margins. 
Thallus bearing isidioid branchlets above, the lobes 
often fringed; exciple often similarly lobulate-fringed. da. P.aquila de- 
tonsa. 
Thallus not isidioid nor lobulate-fringed; exciple crenate 4. P. aquila. 
Section II. Cortical layer cellular. 
Thallus ascending, at least the outer lobes. 
Thallus more or less ascending, with lobes inflated and open 
at the ends...........-..2.0.0...-.-.--0000022------------ 8. P. hispida. 
Thallus ascending toward the margins of the lobes. 
Margins of the lobes strongly ascending, with erose and 
eranulose edges; sea-green above, whitish below...-. 7. P. tribacia. 
Margins of the lobes usually ascending but only mod- 
erately so. 
Thallus sea-green to brown, more or less white-pru- 
inose above; brownish black below.........-.... 5. P. pulverulenta. 
Thallus sea-green to brown, interruptedly ascend- 
ing at the pruinose margins; black below....... da. P. pulverulenta 
leucolerptes. 
Thallus closely adnate throughout. 
Thallus sometimes or always whitish below. 
Thallus always whitish below; sea-green, whitish, or 
brownish above......-.-....---------+-+-+-----++++--- 6. P. stellaris. 
Thallus sometimes darkening below. 
Thallus medium-sized, sorediate above; whitish or 
rarely darkening below...............-..------- 9. P. caesia. 
Thallus small, granulose-crustose and obscurely 
lobed, very closely adnate (adglutinate); whitish 
or darkening below...........----------------- ll. P. adglutinata. 
Thallus dark-colored below. 
Exciple ciliate on the lower side, or over the whole 
outer side, 
Thallus saffron-colored within. ................--- 10a. P. obscura endo- 
chrysea. 
Thallus white within.....................-......- 10. P. obscura. 
Exciple naked............-.--------+-+-----6--------- 6a. P. stellaris apio- 
lia. 
1. Physcia speciosa (Wulf.) Nyl. Act. Soc. Linn. Bord. 21: 307. 1856. 
Lichen speciosus Wulf. in Jacq. Coll, Bot. 3: 119. 1789. 
Thallus one of the largest of the genus, 3.5 to 10 cm. in diameter, smooth, quite 
closely adnate with frequently more or less ascendant margins, commonly stellate, 
the lobes usually elongated, narrow, subdichotomous, with edges usually and upper 
surface rarely more or less sorediate; light or darker sea-green, beneath whitish with 
rhizoids of the same color, the pseudocortex poorly developed below and frequently 
wanting over part of the lower surface; apothecia small to middle-sized, 2 to 6.5 mm. 
in diameter, subsessile, the disk brown and usually deeply concave, the margin 
crenulate or subentire; hypothecium pale or yellowish; hymenium pale throughout; 
paraphyses simple or rarely branched toward the apex, slender, the apices pale and 
scarcely thickened; asci clavate or rarely cylindrico-clavate; spores oblong to ellipsoid, 
23 to 34 » long and 12 to 15 » wide. 
Found in all portions of the State, but scarcely common, On trees and mossy 
rocks. Usually sterile. 
Distributed throughout the northeastern United States, northward and farther 
south in the mountains. Known in all of the grand divisions, 
