PHILOSOPHICAL SOCIETY OF WASHINGTON. 63 



of barren rocks, with lichens their only vegetation, the summit of 

 Roan, and many other peaks, is a smooth, grassy slope, of the most 

 vivid green, dotted with clumps of Alnus viridis, and Rhododendron 

 cataivbiense, the soil one or two feet in depth, rich and black. How 

 this amount of humus was accumulated on these summits, and what 

 cause destroyed the forests which its existence would seem to indicate 

 as formerly existing, are questions not easily answered. 



The valleys are very fertile, and adapted to almost any crop. 



At an elevation of 3,000 to 4,000 feet occurs a belt of the most 

 magnificent forest trees I have ever seen — hundreds of chestnuts, 

 sugar maples, lindens, tulip trees, yellow birches, buck-eyes — some 

 from 4 to 7 feet in diameter, and rising 70 to 80 feet without a limb. 

 One chestnut measured 24 feet in circumference, and one black 

 cherry measured 19 feet. Thorn bushes are as large as old apple 

 trees with dwarf buck-eyes and yellow birches, looked like old 

 orchards of vast extent. 



IV. Flora. 



Ascending the mountain, the vegetation takes on a northern aspect. 

 Hemlocks abound till near the summit, where they are replaced by 

 Abies Fraseri, the characteristic species of these summits. 



Anemone nemorosa, Oxalis acetosella, Rubus odoratus, Ribes lacustre 

 and prostratum, Aster acuminatus, Habenaria articulata, Vercdrum 

 viride, Lycopodium lucidulum, and similar species, remind one of the 

 woods of Maine or New Hampshire. 



The peculiar flora of the upper 1,000 feet, greatly resembles in 

 habit that of the White Mountains, but very few species are the 

 same. Paronychia argyroeoma, Lycopodium selago and Alnus viridis, 

 are almost the only plants that occur to me as identical in the two 

 localities, and these in the White Mountains are found in Crawford 

 Notch, while in Roan they are near the summit. Arenaria grcenlan- 

 dica is replaced by A. glabra, Solidago thyrsoidea by S. glomerata ; 

 Geum radiatum of the North is a variety of that found here ; the 

 two dwarf Nabali of White Mountains are represented by a new 

 species, N. roanensis, Rhododendron lapponicum (four inches high) 

 by magnificent R. catawbiense, covering the summit with its domes 

 of inflorescence six to eight feet in diameter, Castilleia pallida by 

 C. coccinea. 



So that, in general, the species peculiar to these mountains are 

 hardly sub-alpine, and thus continuous with similar species further 



