THE BOGS AND BOG FLORA OF THE HURON RIVER 



VALLEY. 



EDGAR NELSON TRANSEAU. 



(WITH SIXTEEN FIGURES) 

 I. The Huron River valley. 



PHYSIOGRAPHIC FEATURES. 



THE Huron River valley, to the botanical survey of which the 

 present paper forms the sixth contribution, is located in the south- 

 eastern part of Michigan. As indicated in fig. i, the valley embraces 

 parts of five counties. 



Throughout, its surface forms are of glacial origin and, with the 

 exception of the immediate borders of the river, have undergone but 

 slight modification since glacial times. Perhaps its most striking 

 topographic features are the rough morainic hills of its upper and 

 middle courses, and the gently undulating plain of its lower course. 



The river has its source in west-central Oakland County in Big 

 Lake, 9 miles (i4.5 km ) southeast of Holly and approximately 40 miles 

 (64 km ) northwest of Detroit. Starting with an elevation of 950 

 feet (290), after a course, extending for 50 miles (8o km ) generally 

 southwestward and then for another 50 miles (8o km ) southeastward, 

 it empties into Lake Erie at an altitude of 573 feet (i75 m ) above tide. 

 As is common in areas of glacial deposition, the topography of the 

 drainage basin of the Huron has little of the appearance usually 

 suggested by the term "valley." The upper two- thirds of its course 

 is a winding depression among morainic knobs, lake basins, abandoned 

 glacial drainage channels, and sand plains. Here the river is char- 

 acterized by long reaches and occasional slight riffles. At intervals 

 it broadens into stretches of lake-like character, as is illustrated by 

 such bodies of water as Commerce, Taylor, Strawberry, Whitewood, 

 and Bass Lakes, each with an area of one-fourth to one-half a square 

 mile (65-130 hectares). The river margin is usually low and swampy. 



Its tributaries enter it at every angle, and bring to it the drainage 

 of hundreds of lakes and swamps. Most of these lakes are small 

 1905] 351 



