126 GEOLOGICAL SURVEY OP CANADA. 



It is extremely probable that three species are included in the two 

 mentioned above, and that the prairie form is a species intermediate 

 between P. Virginiana and P. demissa. 



(575.) P. serotina, Ehrh. Black Cherry. 

 P. Virginiana, Mill. Pursh, 329. 

 Cerasus Virginiana, Michx. Hook. Fl. I., 169. 

 Cerasus serotina, Loisel. Torr. & Gray, Fl. I., 410. 



Rich woods and fence corners. Growing into a very large tree in 

 western Ontario, where it attains its greatest dimensions, overtopping 

 other trees of the forest. North-west Arm, Halifax, N.S. (Lawson.) 

 Ox Bow, Salmon Eiver, N.B., rare. (Fowler's Cat.} Eastern Town- 

 ships. Q. (Brunet.) Abundant throughout Ontario, and as far west as 

 the Kaministiquia Eiver, Lake Superior. (Macoun.) 



156. NUTTALLIA, Torr. & Gray. (OSO BERRY.) 



(576.) N. cerasiformis, Torr. & Gray. 



Vicinity of Victoria, Vancouver Island, and up the Eraser as far as 

 Yale, B.C. (Macoun.) 



157. SPIR/EA, Linn. (MEADOW-SWEET.) 



(577.) S. salicifolia, Linn. Common Meadow-Sweet.) 

 S. hypericifolia, Marsh. Pursh, 341. 

 S. hypericifolia, var. Plunkenetia, Hook. Fl. I., 171. 



Low damp places, generally near ponds and margins of streams, 

 from Newfoundland, Nova Scotia, New Brunswick and westward to the 

 base of the Rocky Mountains. Point Barrow to Mackenzie River on 

 Arctic Sea. (Pullen.') The leaves of this species assume a multiplicity 

 of forms. 



(578.) S. tomentosa, Linn. Hardback. Steeple Bush. 



Low rich grounds. Common in Nova Scotia. (McKay.) Rather 

 scarce in New Brunswick. (Fowler's Cat.') Not rare in Quebec and 

 extending in Ontario through the northern counties to Muskoka. 

 (Burgess.) 



(579.) S. betulifolia, Pallas. Birch-leaved Spiraea. 



S. chamcedrifolia, var. media, Pursh, 342. Hook. Fl. L, 171. 

 S. corymbosa, Raf. Gray, Manual, 149. 

 S. chamcedrifolia, var. (3., Hook. Fl. L, 171. 



Abundant in thickets on the Cypress Hills and in the Bow River 



