Vol. i No. 9 



TORREYA 



September, 1901 

 DISTRIBUTION OF PTEROSPORA 



By D. T. MacDougal 



Pine Drops [Pterosp'ora Andromedea Nutt.) ranges over a region 

 extending from Mexico northward through California and the 

 Rocky Mountain district into British Columbia, appearing east of 

 the Mississippi River in Michigan, and ranging eastward and also 

 southward along the Alleghany Mountains. These two ap- 

 parently separate areas are probably joined by a belt extending 

 westward through Canada above the headwaters of the Missis- 

 sippi. . The plant is an inhabitant of the pine or transition zone, 

 and its climatal relations are indicated by its limits in southern 

 Arizona, where it occurs only at elevations between 7,000 and 

 8,000 feet. 



In the course of some recent studies on the physiology of this 

 symbiotic saprophyte (Annals of Botany, 1899) the author was 

 unable to obtain living specimens from eastern United States, and 

 from facts given by correspondents and brought to light by the 

 author, it was concluded that this species was moving toward ex- 

 tinction. It has become extremely rare east of the Mississippi 

 River. : not more than a dozen specimens were found in Arizona 

 in a region three hundred miles long, and not a score have been 

 seen in northern Idaho in two seasons' work in collecting. 



During the present season, however, the writer has traversed 

 the Mission Mountains as a member of the Biological Expedition 

 from the University of Montana, and met this plant in great 

 abundance. It is found at altitudes of 3,000 to 4,000 feet in the 

 rich humus of coniferous woods, and at one place east of the 

 southern end of Flathead Lake a hundred stalks were counted 

 within a radius of thirty feet of the observer, and many thousands 



[The exact date of publication of each issue of Torreya is given in the succeed- 

 ing number. Vol. 1, No. 8, comprising pages 85-100, was issued August 23, 1901.] 



