46 A P L O P E R 1 S T O M 1. |_ Polytrichum. 



Polytrichum septentrionale. Swartz, Muse. Suec. t. 9. f. 18. Men- 

 zies in Linn. Trans, v. 4. t. 7. f. 5. Schwaegr. Suppl. v. \. p. 313. 

 Hobson, Brit. Mosses, v. 2. n. 14. f fruit foreign}. Hook. Fl. Scot. P. 

 II. p. 126. Am. Disp. Muse. p. 71. 



P. sexangulare. Hoppe Engl Bot. t. 190G. Funck, Deutschl. 

 Moose, t. 54. B. n. 4. Brid. Meth. p. 196. 

 P. norvegicum. Hedw. Sp. Muse. t. 22. 

 P. crassisetum. De Cand. Fl. Fr. 

 P. helveticum. Schleich. Cat. 



HAB. Highest summit of Ben Nevis, Scotland. In fruit 

 on Brae Reach, and Ben-y-Mac Duich, the highest of 

 the Cairngorum range of Grampian mountains. Messrs. 

 Greville, Arnott, and Hooker, 1822. 



This species has been found in Britain only upon the highest 

 summits of the above mentioned mountains, and was discovered 

 first, in 1808, upon Ben Nevis by Messrs. Turner and Hooker, 

 where, though occurring in tolerable plenty, it did not produce 

 a single capsule. In the autumn of 1822, its fructification was 

 first found, as mentioned above. On the loftiest summits of 

 the Swiss Alps, P. septentrionale is far from uncommon, and 

 fructifies whilst covered with snow, where scarcely any perfect 

 plant can vegetate. It is a species remarkable in the form of 

 its leaves, which are very obtuse, curled when dry, so convex 

 behind as to be semi cylindrical, having their margins, especially 

 at the tops, involute, and there alone slightly serrated. The 

 fruitstalks too, are of a succulent, by no means rigid, texture, 

 and much thickened ; whence the expressive name appropriated 

 to it by De Candolle, and which we should have gladly adopted, 

 were not priority claimed by that of P. septentrionale. We 

 are surprised that Mohr should say of P. sexangulare " optimi 

 juris species, facile dignoscenda," since it precisely agrees with 

 specimens of the present plant that we have received from 

 Swartz himself. We must, however, declare, that neither the 

 figures of Swartz nor of Menzies give a correct idea of its 

 leaves. 



f f Leaves serrated, their margins plane. 



6. P. commune; stems elongated, leaves patent lineari-subulate 

 their margins plane serrated as well as the points of the 



