16 FUNGUS-FLORA. 



** Asci not septate near the base. 



Ascomyces potentillae. Phil., Brit. Disc., p. 402. 



Forming pale, yellowish-green spots on the stem and 

 leaves, these eventually change through brown to purple; 

 asci clavate, apex rounded, 40-50 x 7-8 yu, tapering down- 

 wards into a delicate pedicel often less than 2 ^ thick, which 

 passes between the epidermal cells ; spores hyaline, colour- 

 less, continuous, subglobose or elliptic-oblong, 45 p. diam., 

 or 4-8 X 2-4 p.. 



Exoascus deformans, var. Potentillae, Farlow, Proc. Amer. 

 Acad. of Arts & Sci., vol. xviii. p. 84 (1884). 



Exoascus potentillae, Sacc., Syll., viii., n. 3352. 



Taphrina potentillae, Johanson, Yet. Ac. Handl., 1885, 

 p. 29, t. 1, f. 2; Eobinson, Annals Bot., vol. i. p. 171. 



On living leaves and stems of Potcntilla tormentilla. This 

 fungus also occurs on several other species of Potcntilla on 

 the Continent and in the United States. 



The asci in the Scottish specimen are truncate or rounded 

 at the summit, and attenuated downwards more or less 

 equally to a stem-like base, arising directly from the branch- 

 ing hyphae beneath the cuticle, 30-50 //, high, 7-9 p. in the 

 broadest part, and 2 p. in the narrowest part. The sporidia 

 are confined to the broad upper halt' of the ascus, elliptic, and 

 (as I measure them) 45 X 2-2-5 p.. (Phillips.) 



B. Hyphae spreading only between the cuticle and the epi- 

 dermis. 



** Asci furnished with a stem-cell. 



Ascomyces alnitorquus. Mass. 



Asci irregularly cylindrical, apex truncate, 3540 x 7 /*, 

 stem-cell 12-20 p. long, as wide or even slightly wider than 

 the asci, base narrowed and seated between the uppermost 

 portion of the epidermal cells; spores subglobose, 3-3-5 //, 

 diameter. 



Taphrina alnitorquus, Tul., Ann. Sci. Nat., ser v. vol. v. 

 p. 130. 



Exoascus alni, Do Bary, in Fuckel's Symb. Myc., p. 252 

 (in part). 



