ISOETES SACCHARATA IN THE DELA- 

 WARE RIVER. 



By W. A. Poyser. 



Last July we collected at Delair, New Jersey, a few 

 miles above Camden,, three species of Isoetes, one of 

 which was Isoetes Dodgei. The remaining two were 

 rather puzzling. YVe had expected to collect Isoetes 

 riparia, but could not reconcile the descriptions of this 

 latter species with the material gathered, without leaving 

 a doubt as to the absolute correctness of the determina- 

 tion. Mr. Alvah A. Eaton having kindly consented to 

 give his opinion as to their identity, I sent him a batch 

 of living plants from two colonies. They proved to be 

 Isoetes riparia and /. Dodgei from one and Isoetes sac- 

 eharata from the other — all typical plants. 



Isoetes saceharata grows among the tall river-shore 

 vegetation in very shady soil. Isoetes Dodgei occurs 

 sparingly with a colony of /. riparia extending along the 

 stony beach about eighty paces, forming an irregular belt, 

 averaging about five paces wide. The plants are as plen- 

 tiful as grass upon a lawn, not sharing the space with 

 other species. All the colonies about Delair are immersed 

 at high tide and exposed at low water, at least during the 

 summer. 



Mr. Eaton having expressed a desire to have me look 

 for possible intermediates between Isoetes riparia and /. 

 saceharata, I sent him plants from still another colony, 

 that appeared after a field examination, probable. The 

 results fully justified expectations. In the lot was Isoetes 

 Dodgei (a single plant), a number of /. echinospora 

 Braunii and I. riparia and /. saceharata. The series of 

 specimens collected appear to justify Mr. Eaton's sus- 

 picion that Isoetes riparia is a polymorphic species and 

 includes Isotes saceharata. He has them under culti- 

 vation and hopes to be able to settle this question with 

 the material now on hand. 



Philadelphia, Pa. 



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