190 BOTANICAL GAZETTE [august 



accepts parallel 6o° S. as a more or less natural limit for the antarctic region. 

 Compared with the arctic flora, the antarctic is very poor, including only two 

 species of seed plants (Deschampsia antarctica and Colobanthus crassifolius) , in 

 contrast with about 400 species in corresponding northern areas. The author 

 finds this poverty of vegetation due not so much to the isolation of the land 

 areas in this portion of the Southern Hemisphere as in unfavorable climatic 

 conditions, and chiefly to the very low summer mean temperature, usually 

 below o° C, while in corresponding arctic regions it is well above this point. 

 Skottsberg considers that the remarkably high winds of the antarctic region 

 must also be considered detrimental to the existence of higher plants. A 

 second adverse factor is found in the immense number of penguins that inhabit 

 during their nesting season every bare spot of land, thus preempting the areas 

 with the best soil conditions for seed plants. 



There are no antarctic ferns, but the mosses are represented by 52 species, 

 of which 24 are endemic, 16 northern, and 12 southern. The fact that 16 moss 

 species are common to antarctic and Fuegian lands is perhaps the strongest 

 argument for the Fuegian origin of the antarctic flora. Vegetative reproduction 

 seems the rule among these mosses, very few (6 only) being found with well 

 developed sporophytes. 



Only 6 species of hepatics have been found and but a single fungus, Sclereo- 

 tiiim antardicum, growing among Deschampsia on Danco Island. On the con- 

 trary, antarctic vegetation is rich in lichen display, Darbishire 8 recording 

 106 species, of which 67 are endemic, 25 found also in New Zealand, and 32 in 

 America, these last affording additional evidence of the probability of a migra- 

 tion from Fuegian lands as the origin of the antarctic flora. 



Skottsberg's 9 account of the vegetation of Graham Land, including the 

 South Shetland Islands, is quite in accord with Brown's. The mean summer 

 temperature during the warmest months was — 2^14 C, although the upper- 

 most layers of soil usually thawed for a few hours about midday. The best 

 areas for plant life were the islands and the somewhat elevated rocks which the 

 winds kept comparatively free from snow. Here were considerable areas of 

 moss tundra, consisting of species of Polytrichum, Pogonatum, and Brachy- 

 tkecium, thick mats dominated by Andreaea and Grimmia upon rock surfaces, 

 and a fairly abundant lichen flora, in which species of Placodium, Lecanora, 

 Buellia 7 and Neuropogon were conspicuous. Skottsberg thinks that the 

 present flora is of post-glacial age, but that it also represents the last relic 

 of a vegetation that was formerly somewhat more abundant. — Geo. D. 

 Fuller. 



8 Darbishire, O. \ ., The lichens of the Swedish Antarctic Expedition. Wiss. 

 Ergebn. Schwed. Sudpolar Exped. 1901-1903. 4: Lief. 11. 1912. 



* Skottsberg, Carl, Einige Bemerkungen uber die Vegetationsverhiiltniss des 

 Graham Landes. Wiss. Ergebn. Schwed. Sudpolar Exped. 1901-1903. 4: Lief. 13- 

 pp. 16. pi. 3 and map. 191 2. 



