582 harpee: phytogeography of southern Maryland 



existing maps of geology or soil, and the last includes the re- 

 mainder not otherwise disposed of, which may possibly be sub- 

 divided hereafter. 



Within the last two years the writer has utilized many Sun- 

 days and holidays and a few other days in making pedestrian 

 excursions through all the counties named for the purpose of 

 studying the vegetation and other geographical features. Copi- 

 ous notes have been taken en route, which are now sufficiently 

 complete to form the basis of a fairly accurate quantitative 

 analysis of the existing plant covering, at least as far as the more 

 common and conspicuous native species, especially trees, are 

 concerned.'^ These quantitative studies bring out many dif- 

 ferences that the ordinary fioristic or qualitative lists fail to 

 show; for it happens that the vast majority of the native plants 

 of Maryland belong to common and widely distributed species* 

 (especially is this true of the trees), so that the number confined 

 to any one region would be exceedingly small. 



In this preliminary paper each region will be described very 

 briefly, and then its commonest trees listed as nearly as possible 

 in order of abundance. The wooded area of each region, and 

 the percentage of evergreens in the forests, have been estimated 

 with the aid of Besley's recent report on the forests of the state.^ 

 No attempt is made to assign percentages to the different species 

 at this time, but it happens that the first one in each list con- 

 stitutes not far from 20 per cent of the total, and the numbers 

 for the others would form something like a descending geomet- 

 rical progression (like the population figures for cities arranged 

 in order of size, and numerous other kinds of statistics) . Where 

 it is reasonably certain that a given species is more abundant 

 in one of the regions than in any of the others its name in that 

 list is starred, which will enable the reader to pick out the char- 

 acteristic species of each region at a glance. *= Evergreens are 



3 For an outline of the methods used see 6th Ann. Rep. Fla. Geol. Surv. 177- 

 180. 1914; Torreya 17: 1-2, 5-7. 1917. 



* See Torreya 11: 36. Feb. 1911., 



5 Baltimore, 1917. Reviewed in Torreya 18: 120-122. 1918. 



^ For an application of a method similar to this to the trees of Illinois see 

 Torreya 18: 168-170. 1918. This plan should be useful also to any one desiring 

 a supply of a particular kind of timber, e.g., black walnut. 



