(Hoffman and Alexander 1 987) at higher elevations. Farther east, the Quercus 

 macrocarpa/Symphoricarpos occidentalis plant association is sporadic in hardwood draws and 

 breaks above the Missouri River of North Dakota and South Dakota. 



This association has a drastically different composition and setting from the oak communities on the 

 shale ridges only a couple miles away. It is mesic by comparison, though not as mesic as the well- 

 developed Quercus macrocarpa/Ostrya virginiana p. a. in the Black Hills (Hoffman and Alexander 

 1987) and the Quercus macrocarpa/Corylus cornuta plant association in a few areas of southwestern 

 North Dakota downstream near the Little Missouri River (Girard et al. 1988). 



It is consistent that the sole Montana collection of the wild lily-of-the-valley {Maianthemum 

 canadense) was collected in 1948 from nearby this locality. Its habitat was described as "rich soil in 

 deep woods" (Booth 1950), and this species is known from oak stands in adjoining states. 



36 



