BOTANICAL GAZETTE. 



331 



25. P. Linari^e Fuckel. 



Fungi Rhenani 1903 ; Symb. Myc. 70. 



Conicliophores slender, several times dichotomous. lips short, 

 flexuous, approximate. Conidia obovate, distinctly attenuated 

 at the base, 26-33;/ by 12-16//., violet. Oospores 30-34/*, thick- 

 walled, exospore dark, rough. 



On Linaria Canadensis. 



Chebacco Lake. Mass. (Seymour). 



Apparently a rare species collected in June by Mr. A. B. Seymour. It 

 forms a scanty growth of a dirty white color on the under side of the leaves, in 

 which the oospores abound. The conidia of this species are different in shape 

 from those of our other species and resemble those of P. Schleideniana. They 

 are narrowly obovate and much attenuated at the base. The oospores are 

 rather large and thick-walled, the exospore having more prominent ridges than 

 in the related species. 



26. P. leptosperma De Bary. 



De Bary 1. c. p. 117, PI. IX. f. 1, 2. # «.-,., ., 



Mycelium with globose haustona. Conidiophores rather 

 stout and rigid, several times dichotomous, occasionally trichoto- 

 raous, divisions straight, divergent above. Tips short, spinose, 

 erect. Conidia large, rather narrowly ellipsoid, obtuse, 31-45/1 

 long by 16-22//. broad, white. Oospores yellowish-brown, about 

 38— 45/x in diameter, exospore smooth or with a few folds. 



On Artemisia biennis. 



Lake Minnetonka, Minn. Europe. 



As far as I know the only locality in which this species has yet been found 

 in this country, but it is to be expected on other composites, especially Tanace- 

 tvm. The portions of the leaves attacked quickly shrivel and blacken. I found 

 no oospores on my specimens, and the measurement given above was taken from 

 European specimens. In all other respects the fungus seems to me to be un- 

 doubtedly the same as the European type, and is recognized by the rigid spinose 

 tips and the large white narrowly eliptical conidia. P. Radii De Bary, which 

 sometimes accompanies the present species in Europe, has not yet been found in 

 this country. 



SPECIES WHOSE OOSPORES ARE UNKNOWN. 

 a- Conidiophores pinnately branched. 



27. P. sicyicola Trelease in litt. 



Haustoria not seen. Conidiophores slender, axis long and 

 flexuous, with very numerous 3-4 pinnate, slender, horizontal 

 branches, alternately or frequently oppositely placed. Tips di- 

 vided into several, usually three, very short spines. Conidia 

 small 13-17/x by 11-15/* ovoid, white. Oospores ? 



On Sicyos angulalus. 



Near Madison, Wis. (Trelease). 



This very interesting species was discovered by Prof. Trelease in the sum- 



