North American Species of Puccinia on Carex 221 



the pores obscure, apparently 4, equatorial : uredinia of the modi- 

 fied sort (amphisori) roundish or oval, 0.3-0.6 mm. long, long 

 covered by the epidermis; urediniospores of the modified sort 

 (amphispores) broadly spatulate or obovoid, 20-28 X 32-48 /x ; 

 wall chestnut-brown, 2-3 /x thick, slightly thicker above 3-5 fx, 

 sparsely and inconspicuously verrucose, the pores 2 or sometimes 

 3, equatorial; pedicel persistent, colorless, about length of spore. 



III. Teliospores common in the amphisori, oblong or lanceo- 

 late, 13-19 X 35-50 rounded or often narrowed above and be- 

 low, slightly or not constricted at the septum ; wall pale yellow, 

 1-1.5^ thick, somewhat thicker at apex 2-4 /jl; pedicel colorless; 

 about one-third length of spore or less. 



On Carex exsiccata, Frankii, lurida, scabrata, Sprengelii, Tuck- 

 ermani (on C. vesicaria in Europe). 



Distribution : Known only from isolated localities in the 

 mountains of Pennsylvania, West Virginia, Virginia, in northern 

 Wisconsin, and on the coast of Oregon; also in Europe. 



The discovery, recognition, and finding of additional specimens 

 of this species makes an interesting story. The first specimen 

 was sent from West Virginia by Dr. John L. Sheldon and was on 

 Carex Frankii. This being a common host for Puc. Sambuci it 

 was examined with the expectation of finding that species. The 

 examination, however, showed only i-celled, chestnut-brown 

 spores, now known to be amphispores, but which were then taken 

 to be teliospores of some Uromyces. They agreed with no known 

 species and the specimen was laid aside as a possible new species. 

 Several years elapsed before anything further came to light. 

 Then Dr. J. J. Davis sent in specimens on Carex scabrata and C. 

 Tuckermani which were at once recognized as unusual since they 

 possessed three types of spore forms. Urediniospores of an or- 

 dinary sort and two-celled nearly colorless teliospores, indicating a 

 Puccinia relationship, were present. The most numerous spores, 

 however, were single celled, chestnut-brown, with a thickened 

 apex. Their shape, size, and color indicated at once that they 

 could not be considered mesospores. To be amphispores the wall 

 should have some sort of surface marking and germ pores should 

 be evident and further examination showed clearly that they quali- 

 fied. The West Virginia specimen was then thought of and a re- 

 examination indicated clearly that the supposed Uromyces telio- 



