MARYLAND WEATHER SERVICE 237 



Sugar Loaf Mountain. — This is an isolated portion of the same 

 general elevated land surface as that forming Catoctin, and is sit- 

 uated several miles eastward from Point of Rocks, and slop.- on 

 all sides to the general surface of the cultivated region of the 

 Monocacy Valley. The upper portions, as in Catoctin Mountain, 

 are composed of sandstone, and the debris from the higher parts 

 have become distributed over much of the slope, resulting in a con- 

 siderable amount of sandy soil. The soils at the base, and in the 

 vicinity of Sugar Loaf are of the decomposed igneous type, and 

 form compact loams or clay-loam soils, which support a heavy 

 growth of herbaceous and woody plants. 



Along the northern base of the Mountain a small stream, Thurs- 

 ton Creek, flows westward into the Monocacy, and its banks are 

 covered to a large extent with good forest. Small areas of floodplain 

 soils along the course of the Creek or at points where its side 

 branches join the main stream, afford habitats for the growth of 

 plants requiring deep, moist soil, with much shade. In such places 

 the usual grouping of Benzoin, Hamamelis, Viburnum accrifolium, 

 Fraxinus, Carpinus, Cercis, Fagus and Cornus occurs, while species 

 of Salix occupy the more boggy places of poor drainage along the 

 stream. The Box Elder was here recorded, associated with the But- 

 tonwood, the Elm and the Sweet Birch ; an occasional Hemlock, and 

 a considerable abundance of the Tulip Tree make up the bulk of 

 the tree growth outside of the oak species and the beech and chest- 

 nut. Of the Oaks, the Black Oak, the Chestnut Oak, ami the 

 Overcup Oak were observed at different stations along the water- 

 shed of the stream. The single station recorded for Clitoria 

 mariana in the Upper Midland District is located along this stream. 

 The herbaceous vegetation includes Impatiens aurea, Sanguinaria 

 canadensis, Vagnera racemosa, Asarum canadense, Arabis cana- 

 densis, Impatiens biflora and Hypopotis hypopitis. 



Among the species of ferns noted, the following may be men- 

 tioned: Woodsia obtusa, Dryopteris spinulosa, Onoctea sensibilis, 

 Asplenium platyneuron, Adiantum pedatum, Dryopteris marginalis 

 and Dryopteris thelyptcris. 



The higher and drier slopes of the north side of Sugar Loaf grad- 

 ually rise from the region of the Creek valley southward from the 



