499 



for Arenaria norvegica. 1 am not aware of any other British habitat 

 for it, neither have I seen any foreign specimens. 



Cerastium alpinum, Linn. 



a. Linnceanum^ (Bab. in Mag. Zool. and Bot. ii. 202), C. alpinum, 

 Linn., Eng. Bot. 472 ; Hook. Fl. Scot. 144; Br. Fl. 216. 



Plant 2 — 5 inches high ; stems ascending, mostly simple ; plant 

 covered with a long, white, silky pubescence ; leaves ovato -lanceolate, 

 acute ; hracteas with a narrow membranous border ; sepals sometimes 

 with a nan-ow membranous border ; Jlowers one, two, or three toge- 

 ther in a forked panicle ; peduncle considerably longer than the 

 flower ; Jlowers as in the last ; capsule broadly ovate, shining, twice 

 as long as the calyx, opening with ten teeth. 



&. piloso-pubescens, (Benth. in Lindl. Syn. ed. 1, 51). C. latifolium, 

 Sm., Eng. Bot. 473 ; Hook. Fl. Scot. 144; Br. Fl. 216. 



Stems generally branched, ascending, sometimes rooting at the base; 

 plant with a short, rigid ("yellowish" Hook.), pubescence; leaves 

 oblong, acute ; bracteas often wanting, when present mostly with a 

 narrow membranous margin; peduncles generally one-flowered, long- 

 er than the flower ; capsule as in the last. 



Of this plant Mr. Babington says " I believe that it is correctly re- 

 fened by Bentham to the C. alpinum as &. piloso-pubescens^'' (Bab. 

 in litt.) 



This, with the last, grows on the more elevated mountains of Scot- 

 land, as well as on Snowdon, and I believe other Welsh mountains. 

 /3. seems less common than a., but I have specimens from several 

 mountains of the Cairngorum range, as well as Clova, &c. 



From these observations I think it will be evident not only that the 

 Shetland plant is distinct, but that there exists no specific difference 

 between C. alpinum and latifolium, Sm. and Hook. The differential 

 characters I propose are the following. 



C. alpinmn, Linn, Leaves ovate or ovato-lanceolate, acute ; brac- 

 teas with a membranous border ; sepals with scarcely any border ; 

 peduncle longer than the flower ; capsule twice as long as the calyx. 



C. latifolium, Linn. Leaves orbicular, obtuse ; bracteas without 

 the membranous margin ; sepals with a broad border ; peduncle as 

 long as a flower ; capsule scarcely longer than the calyx. 



2u 2 



