ON RANUNCULACEtE 



217 



conical papilla at the apex, hardly constricted, perfectly smooth, 

 clear chestnut-brown, 30 — 44x13 — 22 /jl; pedicels hyaline, 

 thick, persistent, up to 75 /x long. 



On Caltha palustris. Rather rare. iEcidia, May and June ; 

 teleutospores, July — October. (Fig. 165.) 



There is another British species on Caltha palustris, P. Zopfii, which 

 has been usually confounded with the present one in herbaria. It differs 

 in having its teleutospores broader, darker, more oblong, and covered here 

 and there with minute warts, but is otherwise similar in appearance. There 

 are three others found on species of Caltha in North America, all so nearly 

 allied that they are difficult of discrimination ; but of these one has 

 no uredospores, and the others have, so far as is known, teleutospores only. 

 Some of these may be found in Britain. 



Distribution : Europe, Siberia, North America. 



89. Puccinia Zopfii Winter. 



Puccinia Zopfii Wint. in Hedw. 1880, p. 39, 107. 

 i. 542. Fischer, Ured. Schweiz, p. 91, f. 70. 



Sydow, Monogr. 



Spermogones. Amphigenous or on the petioles, in little 

 clusters of 6 — 10, brownish when old. 



sEcidiospores. J^cidia hypophyllous or on the petioles, 

 usually surrounding the groups of spermogones in scattered 



Fig. 166. P. Zoj>fii. Leaf of Caltha with aecidia ; two teleutospores. 



roundish clusters 1 — 2 mm. diani. (elongated on the petioles), 

 at first hemispherical, then shortly cup-shaped, Hattish, yellow, 

 with a short torn scarcely reflexed margin ; spores delicately 

 verruculose, yellow, 20 — 28 /j,. 



