154 THE PLANT LIFE OF MARYLAND 



found on sandy beaches with its low, branching habit and the persist- 

 ence of its cones. The latter represents part of an almost pure stand 

 in St. Mary's Comity, from which much of the older timber has been 

 cut, showing their habit of growth when crowded. This species is 

 found in every part of the district and in all sorts of habitats, from a 

 clay bluff to a mesophytic valley, though much less common in the 

 latter location. It may occur to the exclusion of all other trees, as on 

 small tracts in many places in Southern Maryland, for example, at 

 Bel Alton in Charles County, and at Hill's Bridge, and South River, 

 in Anne Arundel County. Usually, however, these pure stands are 

 of young trees, representing in a number of cases, a field which 

 had been abandoned for upwards of a score of years. That this 

 species is the pioneer tree in such positions was abundantly proved 

 by observation of all stages of its invasion of vacant areas. In some 

 cases the furrows of the corn field were still distinct, yet the pines 

 upon the area were 10 to 20 feet high. Several features of the 

 Pine enable it to play the part of a pioneer. Its winged seeds cause 

 it to spread more quickly than do trees whose seeds are heavy, as 

 for example, the oaks. Further the pines of this region are able 

 to endure strong insolation and dryness of soil, even in the young 

 stages. Again, they are fast growers, so that they easily overtop 

 other trees which may begin the race at the same time. The con- 

 sideration of a specific case will be of advantage. On a plot 33 feet 

 square in a corn field which has been left for three or four years 

 were found the following: Scrub Pine, 2 seedlings, Loblolly Pine, 

 10 seedlings, (both of these derived from a grove near by), Hick- 

 ory, 1 seedling, Black Gum, 1 seedling, Persimmon, 2 small sap- 

 lings (which had doubtless been allowed to grow while the field was 

 in use) and 3 seedlings, 13 plants of Rubus villosus and Rubus can- 

 adensis, together with herbaceous vegetation such as Potentilla can- 

 adensis, Solidago and Erigcron of several species. Judging by the 

 appearance of neighboring areas, the pines would in a few years 

 overtop the other trees present, and a pure pine stand would occupy 

 the field. 



Habitats where Scrub Pine seems likely to more or less perma- 

 nently xisurp the area are (1) hilltops, on account of dryness of 

 the soil and strength of the wind, (2) sand strands, where the 

 humus content of the soil is insufficient, to support many species, 



