284 



NATURALIST'S GUIDE TO THE AMERICAS 



glacial topography. Northeastern conif- 

 erous forest in which the dominant 

 species is the hemlock (Tsuga canaden- 

 sis). This is an isolatetl grove, marking 

 the northwest limited of the species and 

 situated about 60 mi. northwest of the 

 hemlock forests of Wisconsin. 



Floodwood 8 mi. southeast. Gt. Nor. 

 R. R. 2 mi. northeast of Paupores Sta- 

 tion. 



Gwinn's Bluff. One of the most 

 picturesque bluffs of S.E. Winona 

 County rising nearly 500 ft. over the 

 Mississippi River, flowing along its N.E. 

 base, and situated within the driftless 

 area. The lower slopes of the bluff are 

 covered with a dense hardwood forest; 

 along a stream at the north end of the 

 bluff occurs the witch-hazel, and this 

 spot marks the northwestern limit of the 

 species; nearby is an isolated outpost of 

 Claytonia Chamissoi which occurs typi- 

 cally in the Rocky Mts. and Alaska. The 

 summit of the bluff is composed of 

 dolomite and in the crevices and on 

 upper ledges of this formation occurs a 

 patch of white cedar or arbor vitae which 

 must be regarded as a relic since the 

 nearest station in Minnesota is situated 

 fully 160 mi. farther north. 



Winona 18 mi. S.E. Chi. Milwaukee, & 

 St. Paul R. R. 



About 2 mi. below (a) Richmond. 

 Winona County. 



Jack Pine Grove. About 40 acres, 

 situated on a sandy north-facing hillside 

 in the Root River Valley, about 3 mi. 

 west of Rushford. 



An isolated grove of typical jackpine 

 situated on the border of the Driftless 

 Area, containing in addition to the pine 

 many elements of the northern jack pine 

 forest. Obviously a relic. 



Rushford, Chi. Mill. & St. Paul R. R. 

 Fillmore County. 



Heron Lake. A shallow inland lake 

 in the prairie region of S.W. Minnesota. 

 About 12 mi. long, very shallow in the 

 northern portion, and filled with tall 

 grasses, rushes, sedges, cat-tails and 

 other aquatic plants. Shores with mixed 

 deciduous forest, marshy places with 

 willows. One of the famous nesting 

 places for aquatic birds in Minnesota. 

 Among the species which are still com- 

 mon and nesting among the reeds and 

 grasses in early summer are : The Ameri- 

 can and least bittern, red-winged and 

 yellow-headed blackbird, coot, mallard, 

 pintail, redhead, Florida gallinule, pied- 

 billed grebe, Franklin's gull, Wilson's 

 phalarope, Sora rail, Virginia rail, 

 blue-winged teal, black tern, Forster's 

 tern, swamp sparrow, and prairie marsh 

 wren. Heron Lake, Chi. St. Paul, Minn. 

 & Omaha R. R. 



Jackson County. 



Heil Hollow. A place of great geologic 

 interest embracing an area of about 400 

 acres of precipitous river bluffs along the 

 west side of the Mississippi River, near 

 the southeast corner of the state. Lower 

 slopes heavily clothed with a mixed 

 hardwood forest; upper slopes with 

 perpendicular dolomite ledges in the 

 crevices of which grow red cedar and 

 white pine. In a recently eroded ravine 

 are exposed successively almost down 

 to the river level the Cambrian strata of 

 shale, various sandstones, and mag- 

 nesium limestone. 



About 2 mi. N. of Reno. Chi., Mil- 

 waukee, and St. Paul R. R. Houston 

 County. 



Winnishiek Bottoms. An area of bot- 

 tom lands extending along the Missis- 

 sippi River, a distance of over 300 mi. 

 from Wabasha, Minn., to Rock Island, 

 111. Izaak Walton League Monthly, Vol. 

 1, No. 2, pp. 1, 25, 29, August, 1923. 

 Vol. 1, No. 11, pp. 1, 600-601, 623, July, 

 1923. See Illinois Account.— P. L. 

 Ricker. 



BIBLIOGRAPHY 



1. Nelson, N. P. B. Observations on 



Some Algae Which Cause "Water 

 Bloom." Minn. Bot. Studies, 3: 

 56. 1903. 



2. Roberts, T. S. Review of the 



Ornithology of Minnesota. Re- 

 search Publications of the Uni- 

 versity of Minnesota?: No. 2. 1919. 



3. Upham, Warren. Catalogue of the 



Flora of Minnesota. Geological and 

 Natural History Survey of Minne- 

 sota, Part 4 of Annual Report. 

 1883. 



4. Upham, Warren. Minnesota Geo- 



graphic Names. Minn. Hist. Sac. 

 Coll. 17: 1920. 



5. Winchell, N. H. Geological and Na- 



tural History Survey of Minnesota. 

 1-6: 1875-1901. 



6. Legislative Manual of Minnesota. 



1921. 



16. WISCONSIN 



By a. S. Pearse 

 i. general features and original 



BIOTA 



Wisconsin is essentially a plain, 

 though there are highlands in the north 

 and west. All except the southwestern 

 quarter of the state is covered with 

 glacial deposits, which rest upon Pre- 

 cambrian, Cambrian, and Silurian 



