_ 5 o— 



fact is that it is evidently not common to Polystichum acrosti- 

 choides everywhere, as I only find it on the ferns of one locality. 

 Babylon, N. Y. 



FERNS OF ANN ARBOR, MICHIGAN. 



By Stewart H. Burnham. 



While in attendance at the University of Michigan from 1897 

 to 1899, I found a little time to study the flora of the surrounding 

 region, particularly during the last school year. The native 

 flora is rapidly passing away and to-day is largely confined to 

 small wooded areas and fence-rows. The virgin deep woods, 

 visited — woods that are so typical in New York State and New 

 England, can readily be counted. The woods are usually open 

 and would more correctly bear the name of "woodlands." The 

 soil being gravel, brought down by old glaciers, drys out quickly, 

 hence many of our moisture loving plants, as ferns, do not find 

 a congenial home here. 



The T. & A. woods, three miles south, by the Toledo and 

 Ann Arbor Railroad, is the only typical wood near the city. The 

 soil is rich and the ground often wet and marshy, affording the 

 right conditions for many ferns. Here in company with the fra- 

 gran Phlox divaricata, Claytonia, Cardamines and the rare A plec- 

 trum, grows Adiantum pedatum, Polystichium acrostischoides 

 and the variety incisum, Nephrodium spinulosum intermedium, 

 N. spinulosum approaching dilatatum, Athyrium Ulix-focmina, A. 

 acrostichoides, Onoclea struthiopteris, Botrychium Virginianum, 

 and Lycopodium lucid ulum. 



About the Three Sister Lakes, three miles west of the city, 

 small bodies of water surrounded on all sides by gravelly rolling 

 hills, is another excellent collecting ground, particularly about the 

 most eastern lake, which is surrounded by a quaking tamarack 

 bog. Here may be found .Nephrodium cristotum, N. thelyptcris, 

 Osmunda cinnamomea, O. regalis, which was distorted by a 

 fungus, and Onoclea sensibilis, in company with Sarracenia, Po- 

 gonia, Calopogon and Triglochin. 



Along the Huron river in wooded ravines running back from 

 its banks may be found some of our more uncommon fern allies. 

 Selaginella apus, which closely resembles the mosses with which 



