223 



adnate, lateral, small, concave, margins often denticulate, 



disk chestnut. Spores as in last. 

 Contingent PHASES : (a) Sorediate. 



(b) Branches dilated below (= C hiascens var. dilatata 



Wain., Arkiv. Bot. 8: 22. 1909).* 

 Substrata: On the earth. 

 Distribution: Common in the Boreal zone or alpine above 



4,000 ft. It occurs from Labrador- and Newfoundland 



south to New Hampshire and westward to Alaska. 

 Observations: This species is distinguished from the smaller 



Fig. 5. Range of Cetraria hiascens (Fr.) Th. Fr. 



forms of C. islandica (f. minor Harm.) by its espinulose, 

 lateral margins. It is more easily confused with Coelo- 

 caulon aculeatum (Schreb.) Link though distinctly bifacial, 

 rather than terete, never sulcate and fistulous, and 

 generally glabrous rather than nitidous. In most of our 

 North American herbaria the plant Is labelled C. islandica 

 v^ar. Delisei. Wainio has recognized several varieties in 

 material collected at Pitlekal, Siberia, a point only 150 

 miles from Cape Prince of Wales, Alaska, f and Nylander 

 described a new variety also from "Behring-insula."| 

 I cannot agree with Mr. Merrill that there Is a "parallel- 

 Ism" between the explanate forms of C. islandica and 

 certain plants which he has designated to belong under 



* Type loc, "Pitlekai et Tjapka." Orig. descript. "Thallus laciniis dilatatis, 

 circ. 17-2, 5 millim. latis, applanatis aut partim concavis, apicibus late rotundato- 

 lobatis, rhizinis destitutus, papillis elevatis et spinulis brevibus passim parce 

 marginibus laciniarum affixis, maculis decorticatis albidis cinereisve impressis in 

 latere inferiore instructus." L. c. 



f fastigiata (Del.), rhizophora, Delisei (Bory). 



t submedia, nigricescens. 



