174 THE PLANT WOELD 



of 1901. It is still common in Northern Iowa. Tlie yellow lady-slipper 

 {Cypri'pedium pubescens) was not infrequent in our moist woods some ten 

 and fifteen years ago. Now, however, it is quite rare. The writer has 

 found only a half dozen specimens duriug the last half dozen years. 

 Lilium FhiladeljjMcum formerly was abundant everywhere in the low 

 meadows. While it is not a rare plant now, many of the former local- 

 ities have disappeared. Lilium Canadense is growing scarcer every year. 

 In the marshes of Northern Iowa this plant was once common. It is a 

 rare plant in the vicinity of Ames, though more common in the glacial 

 basin further north. 



The Habenaria leucojyhaea, once common around Ames, has become 

 a rare plant. The large marshes where this plant grew have been 

 drained to a considerable extent ; add to this a series of dry years and 

 it is easy to see how many delicate Avild plants must disappear. The 

 Caltha palusfris and Salix rostrata are plants that love wet spongy 

 places. They are rapidly disappearing. Ten years ago the Gentiava 

 crinita occurred in a small bog on the College farm close to a spring. 

 The dry years 1894 and following seasons made the peaty soil around 

 the spring so dry that it might have burned. The plant has not been 

 found since. Draba CaroUniana was found in a few localities on the dry 

 sterile hills. The close pasturing has removed all traces of this plant. It 

 was found in an unaccountable place on sandy ledges in Hardie county. 



The small Anemone Garoliniana and the Pasque-flower were found 

 by the writer on gravelly drift a few miles from Ames, in 1899. I have 

 been to this locality every spring since, but all traces of these plants have 

 disappeared. The Anemone patens or nuftalUana is, however, common in 

 Northern Iowa, and occurs at a few other stations about Ames. The 

 Anemonella fhalicfroides was frequent in all of our woods ; last spring the 

 writer found few of these plants remaining in the pastured woods about 

 Ames. It was common, however, in protected woods. The Hepatica 

 acutiloha and Glaytonia Virginica still flourish in woods where there 

 is plenty of leaf mould, and where blue grass has not crowded them out. 

 The Heracleum lanatum, once common in all of our rich woods, is disap- 

 pearing except where they are not pastured. So, too, the Thalictrwn 

 dioicum. 



In Central Iowa, not far from Steamboat Rock, there still exists a 

 unique collection of wild plants, perhaps not very different from what it 

 has been for ages. A carboniferous sandstone ledge occurs on the banks of 

 the Iowa river. Here may be found Pinus Sti^obus, Betida lenta, B. 

 papyrifera, Aspidium spinulosmn, A. marginale, Phegopteris Dryopteris, 

 Polypodium vtdgare, Gystopteris hidhifer-a, G. fragilis, Woodsia ohtusa, 

 Lycopodium lucididum, Gornus asperifolia, Diervilla trifida, Gypripedium 

 puhescens, and other boreal plants. The shade of the dense growth of 

 -rees and moisture keeps the soil in good condition for the growth of 



