1903] Yukon Hepatic^. *i3 



YUKON HEPATIC^. 



Alexander W. Evans. 



(With Plates I and II.) 



- Our knowledg-e of the hepaticae occurring" in the Territory of 

 Yukon is based on two collections. The first was made by Mr. 

 R. S. Williams in 1898, the second by Professor John Macoun in 

 1902. Mr. Williams's collection was reported upon by Dr. Mar- 

 shall A. Howe,' who listed twenty-four species. One of these 

 species, however, determined from gemmiparous material, is 

 somewhat doubtful and two additional species have since been 

 detected among Mr. Williams's specimens, so that twenty-five are 

 now definitely known from his collection. Of these twenty-five 

 species, fifteen came from Dawson, while the remainder were col- 

 lected south of the sixtieth parallel and should not therefore, 

 strictly speaking, be included among the hepaticae of Yukon. 

 Professor Macoun's entire collection was made in the vicinity of 

 Dawson and is composed of thirty-six species, including- all except 

 two of those found by Mr. Williams in the same region. At 

 present, therefore, thirty-eight species are known with certainty 

 from Yukon Territory. All of these species have a wide distribu- 

 tion at high latitudes and many of the more common ones are 

 found in temperate regions also. Upon comparing the Yukon 

 species with those found in other arciic countries where the 

 hepaticae are fairly well known, we find that all except two have 

 been recorded from Norway, all except six from Siberia, all ex- 

 cept eight from Greenland, and all except fourteen from the 

 adjacent Territory of Alaska. Eighteen of the species are known 

 from all four of these regions, and it is probable that others have 

 a like circumpolar distribution. Twenty-five ot the Yukon species 

 are known from the United States. 



Two of the species in Professor Macoun's collection, Junger- 

 rnannia Sahlbergii, Lindb. & Arnell, dt.nd Lophosia Kaurini (L,\mpr .) 

 Steph., have not before been recorded from America. The first 

 of these is of especial interest. It was originally described from 

 material collected in the Jenisei region of Siberia. In spite of its 



^ Bull. New York Bot. Garden, 2* : 101-105, pi. /./. 1901. 



