l8l] FLORA OF COLUMBIA AND VICINITY 39 



of the sylva, others in another. The Hanas consist of species of 

 Smilax, Vitis, Quinaria, Rhus, Menispermtim, Celastrus, and 

 Campsis. The shrubs include species of Corylus, Rhus, Vi- 

 burnum, Mespilus, Staphylaea, Asimina, Rhatnnus, Ptelea, and 

 Sambucus. Of undershrubs there are species of Rosa, Riibus, 

 Rihes, Hypericum, and Symphoricarpos. The ordinary sward 

 of the forest floor is composed of Carex Pennsylvanica as pri- 

 mary, with C. Jamesii, C. oUgocarpa, C. rosea, C. Texensis, C. 

 gravida, and C. Hitchcockiana as secondary. Of Gramineae 

 the most important are the species of Muhlenbergia, Brachye- 

 lytrum, Panicum, Bromus, Elymus, and Asprella. The typical 

 ferns are Polystichum acrostichoides, Adiantum pedatum, Cys- 

 topteris fragilis, and Botrychium Virginiamim. The vernal 

 plants belong to such genera as Thalictrum, Claytonia, Dicen- 

 tra, Trillium, Uvularia, Phlox, Polemonium, Ranunculus, and 

 Viola. The aestival plants consist of species of Potentilla, 

 Geranium, Taenidia, Zizia, Cryptotaenia, Sanicula, Blephilia, 

 Agrimonia, and Galium. The autumnal herbs include species of 

 Desmodium, Lespedeza, Seymeria, Gerardia, Rudbeckia, Heli- 

 opsis, Helianthus, Eupatorium, SoUdago, and Aster. 



The white oak, Querctis alba, has a wide range of soils, and 

 may be regarded as the tree most characteristic of the sylva. 

 Though it reaches its best development in the forest plain, it is 

 common in all parts of the forest. It must be said, however, that 

 in the wooded portions of the district underlaid by the coal- 

 measures, the white oak is less frequent than elsewhere. This 

 comparative rarity of occurrence has its explanation in the fact 

 that the region of the coal-measures is properly prairie, and that 

 the forest developed upon it in recent times is of riparian origin. 

 Hence there is seen there the spectacle, nowhere else presented 



