136 SIXTEENTH REPORT. 



at Fort Gratiot, Michigan, now a part of the city of Port Huron. This 

 plant, common at Port Franks, loves the wave-washed shore and often 

 creeps up the first shoreward dune, but very seldom goes beyond. Amophila 

 arenaria and Calamovilfa longifnUa, two grasses not very equally distributed 

 but i^lentiful in places on the beach, the former usually nearer the water, 

 the latter farther up on the beach, but both also noticed on dunes. They 

 are true and efficient sand-binders, both having a root or rootstock system 

 which very effectually protects the sand from the action of wind and waves. 



The beach pea, also frequent at Port Franks, is another strong sand binder 

 and has been known to extend its rootstock in sand over nine feet horizon- 

 tally. J uncus halticus littoralis also frequently establishes itself on the 

 beach as a strong sand binder, but it is common also in other localities. 



The sand dunes are far more stable than the beach and support a more 

 varied vegetation. Since the beach and dunes are the least productive of 

 any part of the county, they are at present useful only for timl)er growth 

 and a small amount of pasture. Generally only the plants adapted to dr}-, 

 sandy conditions, grow on them. The vegetation has not been much changed 

 and hence is fairly primitive. Only those plants thrive w^hich have devel- 

 oped special powers of resistance and can best endure the hard conditions 

 imposed upon them. In this region the dune plant covering varies in many 

 respects in different places. 



Immediately east of Point Edward the dominant trees are white oak, 

 yellow-barked oak, and red oak. Balsam poplar is often abundant on the 

 dune nearest the lake and makes a good sand binder. The bur oak, al- 

 though usually found in rich, damp ground, is frequent here on the shore- 

 ward dune and acts as a good sand binder and dune builder. In this situa- 

 tion, however, it is generally small and scraggy, often having its trunk 

 buried several feet in the sand, but usually producing a great abundance of 

 acorns. White pine and sassafras are also very frequent. The prevailing 

 smaller trees and shrubs are the choke cherry, witch-hazel, Rhus fyphina, 

 R. canadensis, R. toxicodendron, Amelanchier spicata, black huckleberry, low 

 sweet blueberry, and in places Cea/w^/z us ovatus, bearberr}^, Ceauothus america- 

 nus Symphoricarpos racemosus pauciflorus, Rosa humilis, sand cherry, Vitis 

 vulpina, dewberry, and Amelanchier oblongi folia. On the upper beach near 

 many of the summer cottages and along the first dune, Salix purpurea has 

 been planted, thrives, and is proving to be a strong sand binder. The 

 prevailing herbaceous plants, many of them plentiful in places, are Sporo- 

 holus cryptandrus, Elynnis canadensis, Agropyron dasystachyum, Bromus 

 kalmii, porcupine grass, Lithospermum gmeliyii, L. angustifolium, Anemone 

 cylindrica, Arabis lyrata, Liatris scariosa, L. cylindracea, Viola pubescens, 

 V. fimbriatula, V. pedata lineariloba, Senecio balsamitae. Campanula rotundi- 

 folia, Lespedeza capitata, L. frutescens, Acerates virdiflora lanceolata, Poly- 

 gonum tenue, Draba caroliniana, wild lupine, Solidago hispida, S. rigida, 

 Aster azureus, Lilium philadelphicum andinum, Asclepias syriaca, and A. 

 tuber osa. 



Farther to the northeast, beyond Kettle Point and toward Port Franks, 

 where the dunes are more massive, the change in plant association is very 

 apparent. Here the Norwaj- pine (red pine) is well established and abun- 

 dant, reaching its southern limit for this locality. The white pine is far 

 more common, the common junijxM-, low junipc^r antl red cedar become 

 abundant, and two oaks, Q)ierens Mtdilenbergii andQ. prinoides, occasionally 

 seen on or near the dunes farther w&st, become very plentiful at Port Franks. 

 The scarlet oak is occasional. Celtis occidentalis pumila is very common and 



