132 A NATURALIST IN THE GREAT LAKES REGION 



Back of the pine association comes in order the black oak 

 association. No single association of the dune complex is more 

 distinctive than this association, so many of the plants are pecul- 

 iar to it. The black and chestnut oaks are the common large 

 trees. There is a wealth of characteristic small trees and shrubs, 

 sassafras, shadbush, pincherry, chokecherry, hop tree, dwarf 



blackberry, known by its stiff 

 prickers, huckleberry, blueberry, 

 bush honeysuckle. The conspicu- 

 ous herbaceous flowering plants are 

 equally characteristic; the spider- 

 wort, bastard toadflax, anemone, 

 columbine, rock cress, lupine, hoary 

 pea, bush clover, wild geranium, 

 milkweed, flowering spurge, bird's- 

 foot, and arrow-leaved violets, 

 prickly-pear cactus (Fig. 60) , butter- 

 fly weed, green milkweed, wild 

 bergamot, lousewort, blazing star 

 (Fig. 134), the goldenrods, the sun- 

 flowers, and yellow daisy. 



Sassafras (Fig. 112) is readily 

 known by its green twigs with the 

 ,-, ^ . . D7 sassafras taste and its mitten- 



FIG. 113. Poison ivy, Rhus 



Toxicodendron; a, spray showing shaped leaves. Shadbush (Fig. 114), 

 aerial rootlets and leaves; b, fruit also known as sugar plum, service 

 -both one-fourth natural size bugh and June fa j s a small 



(Farmers' Bulletin No. 86}. 



tree with smooth, light-gray bark. 



The leaves of the species in the dunes are thin, and the edges 

 finely saw-toothed. The tree bears clusters of rather large white 

 blossoms in the spring and later edible fruits that turn red and then 

 purple as they ripen. Pin and chokecherries are known by their 

 reddish bark that peels off in thin layers like birch bark, though 

 not so readily, and that is marked by conspicuous horizontal 

 lenticels. Both trees have the blossoms in clusters. In the 



