308 Hill: Notes on Plants of the Chicago District 



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I'gan plant was quite remote from the place where those described 

 by Torrey were obtained, "Lake of the isles, Northwest Terri- 

 tory,".but it has since been reported from the same locality by C. 

 F. Wheeler, as well as from other parts of Michigan. Another of 

 these plants is SdrJ>!/s SviitJdi A. Gray, quite closely resembling 

 small forms of 5. dcbilis Pursh. Both grow in the muddy borders 

 of sloughs in the sand region, the former as yet seen only at 



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Whiting, Ind. 



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articulatiis L., which may be overlooked on account of its resem- 

 blance to /. Ridiardsonii Schult.. a very common species here. 

 /. sdrpoidcs Lam. may be included with them, in general appearance 

 like some forms of /. Torrcyi Coville. It is not assigned to the 

 west by Britton and Brown, but I have known it here since 1876' 

 and have since identified it as collected at an earlier date at Kan- 

 kakee, 111. 



■ Ledges of rock not being common in our area, plants which 

 require or may seek such a habitat are not expected in much' 

 variety. Conditions of this kind exist to some extent along the 

 Desplaines river from Lamont to Joliet, where the Niagara Lime- 

 stone has been scarped out by glacial action, and low cliffs border- 

 ing the flood plain are formed with a talus of rocks at their base. 

 The excavation of the Drainage Canal through this valley, requir- 

 ing much rock cutting, may \\\ time increase these conditions, for 

 crevices above the waterline will be likely to furnish a foothold for 

 such plants, as the rock faces of unused quarries now do. The 

 most interesting plant of this kind is the little fern, PcUaca atro- 

 piirpurea, which clings in abundance to the face of such a cliff at 

 Lamont. Silcne antirrhina divancata Robinson grows with it, its 

 slender sprawling habit making it look quite different from the up- 

 right and stiffer form common in dry ground especially by road- 

 sides. I found it the second time the past season growing under 

 somewhat different conditions on bluffs of clay which border a 

 small stream near Thornton, south of this city, but of the same 

 weak, sprawling character, its branches widely spreading. This 

 adds two more stations in Illinois to the one already reported, 

 Rockford. It was also found last season near Pe'oria. Pentstemon 

 pubesccns Solander is another denizen of the cliffs as well as of the 

 thin soil spread over the rocks which form the glaciated floor of 



