Rhodora 
JOURNAL OF 
THE NEW ENGLAND BOTANICAL CLUB 
Vol. 17. August, 1915. No. 200. 
PLANTS AND PLANT SOCIETIES AT ROQUE BLUFFS, 
MAINE. 
CLARENCE H. KNOWLTON. 
ABOUT 40 miles east of Mt. Desert, and the same distance south- 
west of Eastport lies the town of Roque Bluffs, Washington county, 
Maine. Machias Bay lies just east, and Cutler, across the bay, is 
sixteen miles to the eastward. The body of water just south is called 
Englishman’s Bay, and receives the waters of Englishman’s River, a 
tidal estuary with tributary brooks, named for the first settler. The 
waters offshore are very cold, from the Greenland current, and fogs 
are frequent and dense in summer. This gives the coast a boreal 
climate, although it lies just south of North Latitude 45°. 
The underlying rock is a silicious slate, cut by numerous dikes of 
diabase, many of which have been eroded by the sea, making deep 
sea-caves among the cliffs. West of the slate there is a large area of a 
fine-grained reddish granite, which forms the “red rocks” as the cliffs 
are locally called. This mass, too, has numerous diabase dikes. 
Except for these dikes, the rock is silicious and there is little lime to 
affect the soil and flora. Over the bedrock lies a thick layer of till 
containing many boulders, mostly of granite, coarse and fine. Over 
this in many level places lie beds of marine clay. 
Between two of the rocky points the waves and the 16-foot tide 
have thrown up a half-mile of barrier beach, so wide that the inner 
half of it is under cultivation, and the pond behind it is of water 
entirely fresh. Besides the Englishman’s River there is a smaller 
unnamed estuary, and the salt marshes border these. The rest of the 
shore is rocky and in many places precipitous. 
