THE PLANT WOELD 225 



Iowa, tlie ccmmon oaks, elms, ashes, liawtliorns, maples and cherries 

 are everywliere. 



The Yellow River has certainly many features of interest to the 

 observer of Iowa woodland and prairie. An overland drive across the 

 countj^ of Allamakee takes one along a ridge, almost all the way, over- 

 looking the country for many miles to both east and west. Thus one 

 is afforded an excellent view of the distribution of woods along the 

 streams. On both sides of the Mississippi River at Lansing are high 

 rounded bluffs, with varied groups of plants, from water-loving forms 

 along the river's edge, to those adapted to higher and drier locations. 

 On the north exposures of the bluffs, and especially near the base, the 

 woods are deep, with trees of large and vigorous growth. On rocks in 

 these woods we find the interesting walking fern {Camjjtosorus rhizo- 

 phyllus) ; here, too, stretch great fronds of Osmunda Claytoniana, group 

 after group, fresh and woodsy, with the sunlight drifting in upon them. 

 Along roadsides, and in more open places, the delicate hare-bell is 

 common. From this locality, later in the season, came beautiful speci- 

 mens of fringed gentian and golden-rod. 



The three or four miles of water separating Iowa from Wisconsin 

 flows about numerous islands ; at some seasons many of these are in 

 great measure submerged, but in August they form inviting botanizing 

 grounds. A boat is the ideal conveyance for the botanist, for it brings 

 to his hand the inaccessible, and carries all his burdens for him. 



We ranged along the waterways, finding abundance of the blue 

 lobelias {Lobelia syphilitica) and delighted with the cardinal flower's {L, 

 cardinalis) brilliant touch of color, the great river-gardens of white water 

 lily {Nympliaea tuberosa) and yellow nuphar {Nupliai' advena). Little 

 sandpipers continually moved along the margins of the sandbars, 

 scarcely noting the passing boat. 



Among the interesting water-plants we gathered is the Azolla Caro- 

 liniana. Here, too, we again met the arrow-leaf in profusion with its 

 waxy petals, and Zizania aquatica, that stately grass. When in blossom 

 this admirable and perfect plant rises like a wand at the water-side, 

 crowned wdth bloom j^ellow with pendent stamens. 



In these islands the student of ecology may see examples of the 

 progress of vegetation formation, from those of the mud-flat and water's- 

 edge to the more stable formations of the higher islands. 



