1910] The Ottawa Naturalist. 49 



Liatris spicata, a beautiful plant in bloom, Indian grass, Gej-ardia 

 paupercula and Spartiiia niichauxiana. In spots are found 

 Asciepias sullivantii, Tradescantia refiexa, Viola sagittata, 

 Vernonia niissurica, Polygala incarnata, Panicum virgatwn, 

 Aster inultifiorus, and Cypnpedimn candidwn. 



Xerophytic. 



This plant habitat covers the sandy portion of Lake Huron 

 shore, sand dunes, sand hills, sand ridges, fiat, dry and sandy 

 land, and all dry and sterile ground. The Lake Huron beach 

 included under this division may be regarded as that part of 

 the sandy shore frequently washed by waves. This part has a 

 very sparse vegetation, plants peculiar to itself and not equally 

 distributed. Cakile edentula is seldom abundant, but fairl}- well 

 distributed, and often near the water. Euphorbia polygonijolia 

 is abundant in spots and often in the drifting sand of the beach. 

 Artemisia caudata is frequent, but this is also found on the dunes. 

 One plant of the beach, perhaps deserving particular notice, is 

 Cirsium pitcheri, a thistle known only, I believe, along the Great 

 Lakes, and named for Dr. Zina Pitcher, an army physician 

 stationed more than sixty years ago 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 beyond. Ammophila 

 arenaria and Calaniovilfa longifolia, two grasses often found in 

 abundance on the beach, 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 

 former is usually nearer the water, the latter farther up on the 

 beach, but both are also noticed on dunes. So well adapted are 

 these two grasses for holding down and binding the drifting sands 

 or shores that governments in Europe and America have much 

 encouraged their planting to protect sea coasts and to prevent 

 the sand from encroaching . upon good agricultural land. 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 horizontally. These three plants are said to be abundant 

 in many places on the Atlantic shores. Juncus balticus littoralis 

 frequently establishes itself as a strong sand binder, but is also 

 found in other localities. The sandy beach and sand dunes are 

 the least productive of any part of the county, at present the 

 dunes being useful only for timber growth and a small amount of 

 pasturage. Generally only such plants grow on the dunes as 

 are adapted to dry sandy conditions. Here vegetation has not 

 been much changed and hence is fairly primitive. Only those 

 plants thrive there that can best endure the hard conditions 



