179] FI.ORA OF COLUMBIA AND VICINITY 37 



ized man, then there is none such. All the forests have been 

 more or less pastured, the first-growth timber has been largely 

 removed, and roads and paths have opened them up to weeds 

 and light-loving plants. But if we call virgin those forests that 

 have never been underbrushed, and which still bear a certain 

 percentage of full-grown timber, especially, too, those which 

 have not been excessively pastured and preserve yet a number 

 of rare and local plants, there are still a few secluded localities, 

 which retain in some degree of purity the normal flora of the 

 midland forest. One such tract lies south of Grindstone creek 

 and follows it for a considerable distance. Another is sit- 

 uated across Hinkson creek south, and encloses several deep 

 valleys with spring-fed streams. The flora of these two regions 

 is much alike, both tracts preserving with considerable dis- 

 tinctness the same forest floor. 



The conditions for a forest floor of genuinely sylvan plants 

 are these: i. A shade sufficient to keep out sun-loving intrud- 

 ers. 2. Light enough to make growth possible. 3. The for- 

 est-covering of dead leaves, which rot into a rich, though sour, 

 humus, must be preserved intact. As very practical require- 

 ments, freedom from severe pasturing and from fires is neces- 

 sary. The chief harm from light forest fires comes from the 

 burning up of the rich mulching of leaves and other forest de- 

 bris. Portions of the forests are burned over every year in the 

 hope of securing better pasturage, but w,ith the immediate re- 

 sult that the vegetation, either through the damage done to the 

 roots of perennials or to the destruction of seeds and seedlings, 

 is sparse the whole year through. Such a course, persisted in 

 year after year, obliterates finally the true sylvan societies, and 

 by killing the underbrush ajid by the partial destruction of the 



