DR. HOOKER ON THE DISTRIBUTION OF ARCTIC PLANTS. 333 



includes under it glabraUis, Hook. For my own part, I find it imjoossible to separate the 

 forms of acrls from those of al-pinus, and am rather disposed to refer this to the former. 



E. iiniflorus, L. This is E. alpmtts j3 of Ledebour, and alpimis y of De CandoUe, and 

 is united with alpinus by Bentham also. According to Eries, who unites pulcliellus, DC, 

 with it as a variety, it is a good species. I cannot regard it otherwise than as an arctic and 

 alpine state of alpimis, with a more woolly involucre, fewer capitula, and better-developed 

 inner-ray florets I find all intermediate forms. 



E. purpureus, Ait., is included under Fhiladelphiciis by Torrey and Gray, &c. 



Taeaxacum Bens-leonis, Desf. Eries adopts the name officinale, Weber, and includes 

 palustre as a variety, both being Lapponian, in which Watson, Koch, and most botanists 

 coincide. T. ceratoplioo^um is rather a form with an over-developed condition of the invo- 

 lucral scales, than a variety properly so called. 



T. Scorzonera, B^eich., from Arctic Siberia (Flor. Taimyr.), is not included in Ledebour's 

 ' Plora Rossica.' 



T. phymatocarpimi, J. Vahl, Flor. Dan. 2298, found in Arctic Greeland only, is a small 

 form with the habit and involucre of T. palustre, Sm., and shorter achenia than is usual 

 in the geniis. 



SoNCHUS maritimus, L., is kept distinct by Koch, bu-t included by Fries as a variety of 



arvensis. 



Leontodox autumnalls, L. I am obliged to regard Keretimts, Nyl., as the same with 

 auhimnalis, because Ball (Ann. Nat. Hist. 1850, p. 2) observes that the character of erect 

 and drooping capitulum (on which this species appears founded) is not to be relied on in 

 other species of ■Jhe genus. I have never seen copious specimens of this L. Keretinus, 

 which Ball omits in his otherwise very full account of the genus (/. c.). Fries regards it 

 as a not yet fully developed species. Ledebour puts it in another section of the genus. 

 Koch makes L. Taraxaci, L. {Ap>arg'ia, Smith), a variety of autimmalis ; and Watson 

 says that the British Taraxaci graduates insensibly into autumnalis. Ball makes it a 

 sjTionym. Fries introduces under autumnalis a variety nigro-lanatum ; he describes both 

 as being common throughout Lapland. 



HiERACiTJM. I have grouped the various arctic forms discriminated by Fries, into a 

 few aggregate species, such as are recognized by Arnott, Bentham, Watson, &c. 



Satjssukea alp'vna, L= I have treated this as an aggregate species, because S. mida, mon- 

 ticola, and angustifolia all seem to graduate into it, and several of them into one another 

 I should not be surprised if ^S*. subsimiata, which is hitherto known from one locality 

 only, proved still another form of the same variable plant. 



Cakduus crispits, L. This attains a higher latitude than C. acanthoides, L., of Tiiiich 

 Bentham and otliers consider it a variety. The two certainly pass into one another. 



Campanula linifolia, Hsenke, and Scheiizeri, VilL, are certainly referable to C. rotundi- 

 folia, as held by Linnaeus and most modern authors, though ScJieuzeri is regarded by Fries 

 as distinct. 



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