282 THE PLANT LIKE OF MARYLAND 



Trautvetteria carolinensis, Arabis canadensis and Cimicifuga amer- 

 icana. The last of these is an uncommon Alleghanian species closely 

 resembling the frequent and wide-spread Cimicifuga racemosa. 



Ridges. 



The Ridge type of forest has been seen by the writer at several 

 localities along the summit of Great Backbone Mountain and Big 

 Savage Mountain in Garrett County, and on the summit of Piney 

 Mountain in Allegany County. The type is described by Curran 

 and is indicated on his map of the forest types of the county as 

 extending also along the summits of Negro and Meadow mountains. 



This habitat is poor in tree species, being made up predominantly 

 of Chestnut, Chestnut Oak, and Bed Oak, which together form 75% 

 to 90% of the stand of the second growth forests which now alone 

 represent the Bidge type. The trees of secondary abundance are the 

 White Oak, Shagbark Hickory, Black Oak, Sweet Birch, Sassafras, 

 Cucumber Tree and Linden, — the last two of which are uncommon. 

 There is no sharp line of demarcation between the Ridge and Slope 

 types, the former passes gradually into the latter on the upper slopes 

 of the mountains, as may be seen in descending the road which leads 

 from the summit of Backbone Mountain down to Swanton. The 

 Bidge forest recalls strikingly the forests of the gravel hills of the 

 Lower Midland District, both in the abundance of the Chestnut and 

 Chestnut Oak, and in the herbaceous vegetation. On Piney Moun- 

 tain this resemblance is more close than on the mountains of Garrett 

 County, due to ^he almost pure stand of the two trees mentioned. 

 The shrubs characteristic of the Bidge forest are: Vaccinium 

 slamineum, Gaylussacia resinosa, Vaccinium vacillans, Bibes cynos- 

 bati and Crataegus punctata. Kalinin latifolia, which is so abundant 

 in the Gravel forests, is uncommon on the Ridges of the Mountain 

 Zone, preferring the Rocky Slope forests. 



Among the most common herbaceous plants may be mentioned: 



Hnpatorium ageratoides 

 Aster sagittifolius 

 Potentilla canadensis 



Veron ica officinalis 



