184. THE PLANT WORLD. 



Ills ringens, Eiipatoriinn scrotimiui^ Ilysantlies gratioloides, Eragrostis 

 reptans, Cypcrus diandrus and C. crytJirorhizos. The Cypcrus, 

 Ilysantlies and Eragrostis occur in muddy places of the running 

 sloughs, these being frequently subject to inundations. Lobelia and 

 Minmliis occur on the banks above the stream. These are the most 

 conspicuous of the herbaceous first shore line plants. The first shore 

 line also affords an interesting lot of trees, namely, Gleditsia tria- 

 cantJios, Gyjiinocladus Canadensis, Quercus palustris, Acer dasycarpuvi, 

 Betula nigra a.nd Cephalanthus oecidentalis. Qiiercus palnstris occnrs 

 but little further north in the State ; the only other locality in the 

 north known to the writer is near Wapello, where it has maintained its 

 habit of growing in low alluvial swamps with Betula nigra and 

 Ceplialanthus. The prevailing semi-hydrophytic trees on the island 

 are Acer dasycarpuin and Betula nigra. Throughout the region the 

 common sand-bar willow (5^?//-r/<?;/^//"<?//rt) is common. Salix aniygda- 

 loides and S. nigra are also common species.* 



Second Shore Line. — The body of the island is nearly a level 

 prairie, except the draws and slight elevations which occur here and 

 there. The island no doubt had its origin from an ancient lake-bed. 

 Lakes of similar character, but smaller, still occur at numerous places 

 along the Mississippi. The flora is anomalous, at least as far as the 

 classification of the hydrophytic, mesophytic and xerophytic plants is 

 concerned. Of the xerophytic or partially xerophytic plants, mention 

 may be made of Talinuvi teretifoliuin and Lithospermuni liirtuui; else- 

 where in the State this is replaced by L. canesens, Covimelina Virginica, 

 Tradescantia Virginica, CEnothera rhoinbipetala, Paniciun autumnale 

 and P. capillar e, the latter not common; Paspaluni ciliatifoliiim, 

 Eragrostis pectinacea, Bouteloua hirsnta, Aristida basiramea, Cenchrus 

 tribuloides, Polygonuui tenue, Helianthus petiolaris, Aster ser ice us, A. 

 multijlorus, Asclepias verticillata, Viola pedata, Trifolium reflexuvi, 

 var., Ceanothus Americana, C. ovatus and Rhus Canadensis may be 

 mentioned. These are representatives and well show the character 

 of the vegetation. Cenchrus has spread over the whole island, much 

 to the discomfort of the farmer. Panicuni autumnale, a rare grass in 

 Iowa, grows in large purple masses all over the island where the soil 

 is not cultivated. ThQ Eragrostis pectinacea is less common, but the 

 Bouteloua hirsuta is common everywhere. There are no really turf- 

 forming grasses on the island. The xerophytic grasses, as well as the 

 mesophytic ones, like Panicum virgatum, Andropogon provincialis, A. 

 scoparius, Elymus robustus, Sporobolus keterolepis and i\ Hookerii, all 

 grow in bunches. In many cases these are beautiful large gi^asses. 



* I am indebted to Mr. C. R. Ball for the identification of the willows, and to Mr. Reppert for 

 kind favors shown me. 



