189] FLORA OF COLUMBIA AND VICINITY 47 



cula Canadensis, diVe the commonest herbs with the exception 

 of the brome and lyme grasses (species of Bromus, Elymus, and 

 Asprella). 



e. Autumnales. 



The autumnal and late summer vegetation consists of such 

 plants as Gerardia Besseyana, Campanula Americana, Lobelia 

 syphilitica, Rudbeckia triloba, Etipatorium ageratoides, and 

 Solidago flexicaulis. 



ii. Sylvales quercoides juglandinae. The walnut sub- 

 association of rich slopes consists of Juglans nigra and the var- 

 ious hickories (Carya spp.), Querciis alba and Q. acuminata, in 

 control, but often thickets of Ostrya Virginica cover the lower 

 slopes and form a transition to the preceding. Frequently the 

 hillsides are covered with patches of shrubs, notably Rhus 

 glabra and Corylus Americana. The herbs in general are those 

 common to the sylva. Thalictrum anemonioides, Trillium ses- 

 sile, Corydalis montana and Dicentra Cucidlaria are frequent 

 early spring species. Later Camassia Fraseri, Delphinium 

 tricorne, Verbena Aubletia, and Erigeron pulchellus occur in 

 large patches. Oxalis violacea and many violets {Viola spp.), 

 are common, as are also Phlox divaricata and Polemonium rep- 

 tans. In summer species of Galium, Agrimonia, and Desmodium 

 are characteristic. The usual sylvan ferns also abound. The 

 most striking herb of the richer slopes is, however, Veratrum 

 Woodii. The autumnal herbs consist mainly of Compositae, 

 among which species of Helianthus, Eupatorium, Solidago and 

 Aster are preeminent. 



iii. Sylvales quercoides fraxininae. The blue ash sub- 

 association of hill summits consists of a scraggly growth of 

 Fra.vinus quadrangidata, Quercus tinctoria, Q. alba, Q. imbri- 

 caria, and Diospyros Virginiana. Shrubs and undershrubs are 



