MARYLAND WEATHER SERVICE 161 



The herbaceous vegetation includes a large number of shade and 

 moisUire-loving species. 



Lowland Forests. — This division includes the growth on the 

 low-lying tracts bordering the larger bodies of water, also the flood 

 plains of streams. It does not present the same variety as the first 

 division, for the conditions are not so diversified. At the same 

 time the vegetation is more luxuriant, on account of the better sup- 

 ply of moisture. Two associations may be distinguished. 



Gum-Pine Association. — On the soil areas marked "Meadow" 

 on the soil maps, namely the low flat areas bordering on the larger 

 bodies of water, is found a characteristic assemblage of trees. The 

 areas are poorly drained, and as was stated in the section on soils, 

 the material is a fine gray silty loam. An extended area of this 

 kind occurs in the peninsula between the Potomac and Wicomico 

 rivers in southern Charles County, also at the south-east extremity 

 of St. Mary's County. On these areas the dominant tree is the 

 Sweet Gum Avhich occurs in all sizes and overruns the roadsides 

 like a weed. A glance at Table 1 will show that it is in this asso- 

 ciation that the Loblolly Pine reaches its maximum development. 

 In some places in fact it is the dominant tree, as was mentioned 

 when considering the Pine Association, but generally it is outnum- 

 bered by the hardwoods. The Scrub Pine is frequently found 

 mixed with the Loblolly and the hardwoods and there is the same 

 struggle for supremacy between hardwoods and conifers as was seen 

 on the uplands. One other conifer, the Red Cedar, is especially 

 common in the regions near the water. A highly characteristic tree 

 is the Willow Oak, which though often outnumbered by White Oak 

 and Black Oak, reaches its best development here. Other trees of 

 conspicuous occurrence are the Spanish Oak, Black Gum, the Per 

 simmon and the Maple. Quite as conspicuous, — by their rarity, — 

 are the Tulip-Tree, the Hickories and the Chestnut. This may be 

 accounted for by the poor drainage of such areas and by a possible 

 chemical factor; the chestnut having long had a reputation for avoid- 

 ing calcareous soils, which would account for its greater abundance 

 on sandy hillsides. Characteristic members of a lower zone are : 

 the Holly, which is especially abundant in this association, the Sass- 

 afras; Dogwood, Sumac and Sweet Pepper-bush. 



