JIARTLAXD GEOLOGICAL SUKTEY 187 



them in j-ards and along roads and lanes. A few of these species have 

 escaped from cnltivation and are found mixed with the native trees 

 along the borders of wood lots. The most important ones are: 



Common Xame. Botanical Name. 



Norway Spruce Picea excelsa Link. 



.Silver Fir Abies pectinata D. C. 



English Walnut Juglans regia Linne. 



European Hornbeam Carpinus hetulus Linne. 



Weeping Willow Salix habylonica Linne. 



Paper Mulberry Broussonetia papyrifera (Linne) 



Vent. 



Tree-of-Heaven Ailanthus gJanduJosa Desf. 



Paulownia Paulownia tomentosa (Thunb.) Steu- 



del. 

 Catalpa Catalpa Tcwmp^eri Seib. and Zucc. 



Types of Forest. 

 The forests of St. Mary's Coimt_y are conveniently divided into three 

 types: (a) Mixed hardwoods, (b) mixed hardwoods and pine, (c) 

 pure pine. 



(a) The mixed hardwoods cover the largest percentage of forested land 

 in this county, and invariably occupy the rich, gravelly soil along the 

 water courses. The predominating species of this type are red gum, 

 yellow poplar, black ash, sycamore, oaks, beech, and white elm. The 

 most valuable timber is now being cut from this type, while several species 

 are continually culled out for special purposes. Through this cutting 

 the mixed hardwood type has greatly diminished in value. The best 

 and also immature trees are removed, while the over-mature and forest 

 tree weeds are left to grow and prevent the best species, such as the 

 yellow poplar, ash, and red gum, from reproducing. 



(b) The mixed hardwood and pine type occupies the area immediately 

 bordering the mixed hardwood type. The principal trees represented are 

 the red and white oaks, sour gum, scrub pine, and a small amoimt of 

 loblolly pine. This type covers the well-drained areas which have never 

 been cleared for agricultural purposes. This forest is more or less open, 

 and shows a tendency to predominate, especially on the borders of open 

 fields and roads. 



