torrp:ya Zz:,z 



October, igog 

 Vol. g No. ic 



STUDIES IN THE OPHIOGLOSSACEAE — III : KEY 



TO BOTRYCHIUM IN NORTH AMERICA : 



GROUP OF B. TERNATUM 



By Ralph Curtiss Benedict 



The present paper is in completion of the series begun about a 

 year ago, when keys to Ophioglossinn in the United States and to 

 the lanceolatuvi group of Botrychiuvi for all North America were 

 published. As was the case in those keys, the present key in- 

 cludes some forms which may not deserve recognition as species, 

 but which are included in the hope that more information may 

 be forthcoming as to their status. Some of the characters given 

 here may prove inconstant, and the forms distinguished by them 

 would then need to be reduced, but on the other hand, further 

 field study may bring to light additional reasons for regarding 

 others as distinct. 



It is scarcely necessary to call attention to the fact that our 

 present knowledge of these plants is almost entirely due to Dr. 

 Underwood's pioneer work with them. This is true whether orj not 

 one accepts his conception of species, since there can be no ques- 

 tion that he has indicated the more distinctive forms, whatever 

 standing they may eventually be accorded. The recognition ac- 

 corded them in the present treatment is based on a study of a 

 large amount of material, and, I believe, will be found to be justi- 

 fied by the facts at hand. 



In order that the group may be treated here as completely as 

 were the other two, the characters by which it is to be distin- 

 guished from the lanceolatum grow'p are reprinted from the second 

 paper as follows : 



" Group of B. ternatiim: Bud hairy, common stalk hypogean, 



[No. 9, Vol. 9, of ToRREYA, comprising pages 177-196, was issued September 

 27, 1909.] 



197 



