MICHIGAN ACADEMY OF SCIENCE. 255 



Aug., 1888); St. Clair Co. (C. K. Dodge, Sept., 1892); Keweenaw Co. (0. A. Farwell- 

 1886) ; Isle Royale (Dr. A. E. Foote, 1868) ; Mackinac Island (T. S. Boyce, July, 1881) ; 

 Iron Co. (C. A. Davis, Sept., 1905). 



Reported from : — Kent Co. (Emma Cole) ; Jackson Co. (S. H. Camp) ; Leelanau Co. 

 (E. J. Hill); Tuscola Co. (C. A. Davis); Cheboygan Co. (Miss Anna Arbuthnot); 

 Emmet Co. (Fallass and S\\aft). 



Most collectors in the state have referred this species to S. romanzoffiana Cham., 

 an Alaskan plant. 



4. Ibidium cernuum (L.) House, (nodding). 

 Spiranthes cernua (L.) Richard. 



Wet meadows and swamps throught. Frequent. Aug. — Oct. Very vari- 

 able. 



Specimens examined: — Gratiot Co., Sept. 1892; Cass Co. (H. S. Pepoon, 1906), 

 No. 865; Marquette Co. (B. Barlow, July, 1901, Ottawa Co.) (L. J. Cole, Aug., 1895); 

 Macomb Co. (Dr. D. Cooley, Aug., 1848); Hillsdale Co. (H. B. Crosby); Ionia Co. 

 (C. F. Wheeler, Sept., 1890); Ingham Co. (F. L. Sleeper, Sept., 1866); Washtenaw 

 Co. (A. J. Pieters, 1892); Van Buren Co. (Judge A. W. De Selm, Aug., 1913); Mack- 

 inac Island (C. F. Millspaugh, July, 1898) ; Allegan Co. (U. A. Dohmen, Aug., 1898); 

 Jackson Co. (S. H. and D. K. Camp, Aug., 1897); Houghton, St. Clair and Schoolcraft 

 counties (C. K. Dodge). 



Reported from: — Kent Co. (Emma Cole); Wayne Co. (O. A. Farwell); Calhoun 

 Co. (C. E. Barr); Tuscola Co. (C. K. Dodge); Jackson Co. (S. H. Camp); Charity 

 Is. (C. K. Dodge); Bois Blanc I. (C. K. Dodge); Emmet Co. (Fallass and Swift); 

 Oakland Co. (C. Billington). 



Ibidivvi ovale (Lindl.) House., known to occur in Ohio and Illinois, may be looked 

 for in the southern part of the state. Stem 1-3 dm. high; leaves somewhat broader 

 and spike narrower than /. cernuum, which it resembles. 



18. OPHRYS [Tourn.] L. Twayblade. 



Column less than 1 mm. in length; raceme glabrous 1. O. cordata. 



Column 2-3 mm. long; rhachis pubescent or glandular-pubescent. 



Ovary glandular; lip not auriculate at base 2. 0. convallarioides. 



Ovary glabrous; lip auriculate at base 3. 0. auriculata. 



1. Ophrys cordata L. (heart-shaped). 

 Listera cordata (L.) R. Br. 



Damp mossy woods, cedar swamps, etc. Infrequent. June — Aug. Com- 

 moner in the Upper Peninsula . 

 Specimens examined: — Keweenaw Co. (O. A. Farwell, 1887); Marquette Co. (B. 

 Barlow, June, 1901) ; Isle Royale (Douglas Houghton, 1840) ; Alger Co. (C. K. Dodge, 

 1916). 



