6 llnucrsily of Michigav 



blueberries (Vaccinium spp.), sassafras, the bush honeysuckle 

 {DierznUa lonicera), and other plants of similar habits; the 

 prickly pear (Opii)itiu rafincsquei) occurs on the dunes at 

 New Buffalo, but does not appear to pass the Galien River. 



The transition stages from the black oak to the beech-maple 

 forest are more gradual than the stages which precede the 

 oaks, and the associations are less clearly defined. At first 

 the stand of black oak is almost pure, but farther from the lake 

 other trees appear, such as the chestnut oak {Quercns muhlen- 

 bcrgii), the blue beech (Carpinus caroliniana) , the basswood 

 {Tilia americana) , and the hop hornbeam {Ostrya virginiana) . 

 The white oak (Oucrcus alba) becomes more and more plenti- 

 ful as the black oak disappears, until finally an association is 

 formed in which the white oak is predominant. This is the 

 last association which is found in a typical form on the Sawyer 

 Dunes, but even here numerous maples (Acer saccJiarum) 

 and occasional beeches (Fagus grandifolia) foreshadow the 

 climax forest. 



The climax forest is splendidly represented in the \\'arren 

 Woods, about three miles north of Three Oaks and two or 

 three miles back from the dunes. Mature beeches and maples 

 form at least ninety per cent of the forest on the higher 

 ground, and undergrowth is very scanty. The Galien River 

 flows through the woods, and its flood plain supports a more 

 varied flora : here, besides the beeches and maples, there are 

 elms, butternuts, and sycamores; elders (Sambucus spp.) and 

 dogwoods are numerous, and the herbaceous vegetation is 

 plentiful. Occasional sandy beaches by the river are excellent 

 habitats for Gelastocoris and the Saldids, and numerous 

 shaded pools in the woods oiTer their attractions for some of 



