15 



Floral Areas of Indiana (See map on page 1164.) 



To assist in understanding the distribution of a species in the state and 

 at the same time give some idea of its habitat, I have divided the state into 

 seven areas. These are not all strictly floral areas but for convenience they 

 may be so considered. The limits of the ranges of certain species within 

 the area determine one boundary of that area. 



Dune area 



The dune area is bounded on the north by the waters of Lake Michigan 

 and on the south for the most part by the Michigan Central Railroad. It 

 is about four miles wide at the west end and half a mile wide at the east 

 end. In Lake County this area consisted of low dunes, for the most part 

 from 5 to 15 feet high, alternating with sloughs and interdunal flats. In the 

 extreme northwest part of it were Wolf Lake, Berry Lake (now extinct), 

 and Lake George. The greatest variety of plants of this area were found 

 in this county. In the east part of Lake County the dunes begin to rapidly 

 increase in height and high dunes continue to Michigan City. The highest 

 dune is Mount Tom in Dunes Park, Porter County and is 192 feet high. 

 The dunes proper are almost pure sand but were formerly well wooded. 

 The sloughs and interdunal flats are more or less mucky. 



The following list is of plants known in Indiana only from this small 

 area and all are of northern range. Those preceded by "?" are probably 

 extinct and those preceded by "o" are now known from one colony only. 



Ammophila breviligulata 

 ? Botrychium simplex 



Cakile edentula var. lacustris 



Carex folliculata 



o Carex Richardsonii 



? Ceanothus ovatus 



Cirsium Pitcheri 

 o Clintonia borealis 

 ? Corallorrhiza trifida 



Cornus canadensis 



Cyperus Houghtonii 

 o Equisetum variegatum 



Euphorbia polygonifolia 



Hudsonia tomentosa var. intermedia 

 o Myosotis laxa 



Oryzopsis asperifolia 

 ? Panicum lucidum 



? Panicum scoparioides 

 ? Panicum subvillosum 



Pinus Banksiana 

 o Polygala paucifolia 



Potentilla Anserina 

 o Potamogeton pusillus 

 ? Psilocarya nitens 

 ? Pyrola secunda 



Ptelea trifoliata var. Deamiana 

 ? Rhynchospora cymosa 



Salix adenophylla 

 o Scirpus subterminalis 



Shepherdia canadensis 

 o Solidago Deamii 



Solidago Gillmani 

 o Thuja occidentalis 



Lake area 



The lake area occupies the northern part of the state, southward to the 

 Tipton Till Plain but is not sharply separated from it. For practical pur- 

 poses the south line of this area may be considered to coincide with the 

 north line of the Tipton Till Plain which may be given roughly as a line 

 extending westward from Fort Wayne to Huntington, Logansport, and 

 Monticello to the state line. South of this line are a few, nearly extinct 

 small lakes. There is one in each of the following counties: Wells, Black- 

 ford, Grant, and Warren. Deep peat deposits in Hamilton and Madison 

 Counties indicate extinct lakes. 



