496 Part IV. Chapter 2. 
(Alnus Association). The alder covers an adjoining dome of the Roan 
mountain range, the Elkhorn, with a pure and impenetrable growth three to 
four feet high. The extent of the rhododendron thickets, for which the moun- 
tain is famous, cannot be easily estimated. The bushes may be either roun- 
ded, like a hay stack, or they may be spreading at the top ''). 
The summit of Roan Mountain is in the form of a saddle several miles long, being for- 
med of two elevations of about equal height, the culminating peak being 6313 feet (1924 m) in 
altitude. The component vegetation of the grassy meadows, or ”balds“ consists of Danthonia 
compressa (the most abundant grass in dense tufts), Trifolium repens, Rumex acetosella, Poten- 
tilla canadensis, Poa compressa, Veronica offieinalis, Houstonia serpyllifolia, Carex tenuis, De- 
schampsia flexuosa, Luzula an and Phleum pratense (Carex-Poa Association) with the 
following grasses noted by LAMSON-SCRIBNER: Agrostis perennans, A. scabra (= A. hiemalis), A. 
a, Cinna pendula (= C. mie Sranbyehjfeue aristatum (= B. erectum), Calamagrostis cana- 
densis, Eatonia pennsylvanica, Glyceria u. Poa annua, Poa pratensis, Poa alsodes, Bromus 
eiliatus, Elymus striatus, Asprella hystrix, Danthonia spicata, Trisetum subspicatum var, molle? 
Polytrichum commune forms patches, urn about old stumps. 
The raised cushions of soil found here are covered by various mosses 
with Leiophyllum (Dendrium) buxifolium?) (Dendrium Association). In or 
along the dry stony-wash-ways, one finds Sarifraga leucanthemifolia, FPoten- 
tilla tridentata, and Houstonia purpurea. 
The immediate summit of Roan Mountain is characterized by the presence 
of Geum radiatum, Lycopodium selago, Menziesia pilosa, Houstonia purpurea, 
Lycopodium lucidulum, Ribes rotundifolium, Leiophyllum. Alnus viridis clings 
to the northern slopes, here forming a pure growth on the steeper inclines 
(Alnus Association), with Sordus americana below it, but associated with 
Rhododendron catawbiense on the upper slopes of the dome. 
Among the rocks and on the edges of the precipices are found Paronychia argyrocoma, Heu- 
chera villosa, Sedum rhodiola, S. telephioides, Angelica Curtisii, Campanula divaricata (= 
xuosa), Carex aestivalis, C. debilis, C. juncea and under the overhanging cliffs the delicate Ze 
Saxifraga Careyana 
Crossing Carver Gap, where Aesculus flava grows PATER Facies), a rocky outcerop is 
found on the slope of Little Roan Mountain where the writer collected Rhododendron calendu- 
laceum, Oenothera (Kneiffia) fruticosa, Geum geniculatum, Arisaema quinatum and rn gra- 
veolens (Kneiffia-Hypericum Association). Here grow according to Chickering4), D elphinium 
exaltatum (= D. urceolatum), Silene virginica, Liatris spicata, Rudbeckia triloba, Castilleia coccinea, 
Physostegia virginiana, Melanthium virginicum. Alder Bald o r Elkhorn, as it is called, is reached 
from Little Roan Mountain by crossing a smaller wind gap. The slopes of this knob are covered 
by acres of Alnus viridis (Alnus Association), under which grew formerly the rare Li jum 
Grayi while the stony _ are favorable for the growth of Heuchera villosa, Krigia montana, 
Cerastium vulgatum, an alpine species, Potentilla tridentata and Arenaria (Alsine) groenlandica. 
The latter herb assumes eu cespitose character in exposed situations. 
ı) Cf. Cannon, W. A.: Field notes on Rhododendron Catawbiense. Torreya je 161. 1902. 
2) LAMSON-SCRIBNER, F.: The Grasses of Roan Mountain. Botanical Gazette XIV: 253- 
A > Cf. SmaıL, J. K.: Flora of western North Carolina and EEE territory. Mei. Tost, 
ot. Club 3. 
4) CHICKERING, J. W.: A Summer on Roan Mountain, Botanical Gazette V: 144— —148; 
Brıtron, E. G.: Botanical Notes in the Great Valley of Virginia and the southern Alleghanies 
Bulletin Torrey Botanical Club XII: 69—76, 
