1906] Ames, Habenaria orbiculata and H. macrophylla 5 



//. orbiculata. 



Length (mm.) 16 17 18 19 20 21 22 23 24 25 26 27 28 29 



No. of cases observed, 22779412132100 



//. macrophylla. 



Length (mm.) 30 31 32 33 34 35 36 37 38 39 40 41 42 43 

 No. obs. 101637212011 



These figures illustrate the fact that in Habenaria orbiculata Torr. 

 the most frequent spur-length is about 2 cm. and that in //. macro- 

 phylla, Goldie, the most frequent length is 3.5-3.7 cm. The flowers 

 of H. orbiculata are considerably smaller than those of H. macro- 

 phylla, as is shown by the accompanying text cuts. The following 

 shows what seems to be the most satisfactory treatment of the species 

 herein considered. 



Habenaria orbiculata, Torrey, Compendium, 318 (1826). — 

 Orchis orbiculata, Pursh. Fl. Am. 2: 588 (ISU).— Platanthera Men- 

 ziesii, Lindley, Orch. PI. 286 (1835). Lj/Ma^ orbiculata, Rydberg, 

 Britton's Manual 294, in part.— Spur 1.6-2.7 cm. long. South Caro- 

 lina, Tennessee, Maine, westward to Minnesota and Washington, 

 and northward. 



Habenaria macrophylla, Goldie, Edinb. Phil. Journ. 6: 331 

 (1822). — Platanthera orbiculata, Lindley, Orch. PI. 286 (1835).^ 

 H. orbiculata, Pritton and Brown, 111. Fl. 1: 461 (excl. Hg.).— Lysias 

 orbiculata, Rydberg, Britton's Manual 294, in part.— Spur 3.2-4.3 

 cm. long. Connecticut to Wisconsin and northward. 



North Easton, Massachusetts. 



