197 



Potamogelon. Any systematist who has undertaken a study of this genus, will 

 at once appreciate the fact that the value of specific determinations is largely in- 

 creased if they have received the sanction of a specialist in the group. Mr. Hill's 

 forms of this genus have undergone the scrutiny of the late Dr. Thomas Morong 

 and may be added with confidence to the state flora. It is therefore with very 

 great diffidence that I venture to question the determination of one or two of 

 the sheets sent the Survey. The question is not of the original determination, but 

 the suggestion is made that in the distribution there has been a confusion of forms- 

 The most noteworthy species of this genus are the following: 



P. pulcher Tuckerm. "Shallow ponds, Pine Station, Lake Co., June 21, 

 1884." (E. J. Hill.) From an examination of many specimens, I am led to be- 

 lieve that this form as received by the Survey should be referred to P. amplifoliiis 

 Tuckerm, because of leaf and fruit characters. The range of the two forms is 

 practically the same and it is possible that they may be found associated, and be- 

 come mixed in distribution. The size of the fruit is perhaps the most apparent 

 distinction between the two forms. In addition to P. pulcher Tuckerm, P. ainpH- 

 foliux Tuckerm is also without doubt a member of the state flora. 



P. pr(dongns Wnlf. Cedar Lake, Lake Co., Ind., Feb. 27, 1882. (E. .J. 

 Hill. ) This well marked form should be more generally found in the northern 

 counties of the State. The region is fairly within the range of the plant and the 

 conditions for its occurrence are good. It has, however, been reported from no 

 other locality, so far as I have knowledge. 



P. Eobbinsii Oakes. "Cedar Lake, Lake Co., Ind., June 30, 1886." (E. J. 

 Hill.) This is another interesting northern form added to the Indiana flora as a 

 result of Mr. Hill's indefatigable work. (Man. 6th edu. 735c.) 



In the specimen sent the Survey by Mr. Hill, both fruit and flowers are 

 absent. From this specimen standing alone, I would refer the form to P. murinus 

 L., since the leaf and stem characters do not conform to the description of P. 

 Robbinsii. My very high appreciation, however, of the skill and acuteness of Mr. 

 Hil'i lead me to include the form P. Robbinsii Oakes, and also to add the species 

 P. viarinus L. 



I am inclined to believe that a moi-e careful study of the plants of our marsh 

 and lake regions would result in the extension of the range of many forms in this 

 and allied groups. 



Eriocaulon xeptanf/i/lare Withering. " Sandy borders of ponds, Laporte, Ind., 

 July 22, 1875. Scapes 6-8 striate." (E. J. Hill.) The addition of Indiana to 

 the assigned range of tliis plant in the 6th edition of Gray's Manual was based 



