LEPTO MIT ALES 903 



Springer (S.), Sparrow (1943: 590), fruits of Amelanchier, Sparrow and 

 Barr (1955: 555), R. M. Johns (comm.), Emerson (comm.), (Pennsyl- 

 vania), United States; twigs, Hohnk (1938: 499), Germany. 



See Emerson's findings concerning formation of spiny sporangia 

 (p. 855). 



MlNDENIELLA ASYMMETRIA Johnson 



Amer. J. Bot., 38: 74, figs. 1-25. 1951 



"Basal cell bent-clavate, slightly irregular in outline, often once- 

 branched in the lower portion; 175-515 \x long in the longitudinal axis, 

 181-290 u. long in the horizontal axis, 91-143 [jl in diameter across the 

 bent portion, predominantly 400 < 250 x 125 u,; attached to the 

 substratum by much-branched, sharply pointed rhizoids; wall variable 

 in thickness in the same thallus, apparently laminate. Zoosporangia 

 1-14, borne at or near the distal end of the horizontal portion of the 

 basal cell on slender, variable-length pedicels closed with cellulin plugs; 

 predominantly short-ovoid or short-pyriform, rarely long-clavate, and 

 then usually once-branched at the base; 47-88 \x in length by 32-65 \x 

 in diameter, predominantly 60-70 \x ■ 40-50 \x; clavate zoosporangia 

 averaging about 115 25 [jl; wall moderately thick, predominantly 

 smooth, but occasionally with 20-30 or more solid, sharp-pointed 

 spines in the upper one-fourth of the sporangium wall. Zoospores 

 reniform, biflagellate, escaping from the zoosporangium through an 

 apical exit papilla, and swimming away at once; 5-9 \x long by 3-7 \x 

 in diameter, predominantly 6-8 \x 4-6 \x, and averaging 7 X 5 (x. 

 Resting spores intermingled with the zoosporangia or on separate 

 thalli; pedicellate, with a thick wall, and with prominent, solid, sharp- 

 pointed spines in the upper one-third or one-half of the spore wall: 

 spherical; 38-87 \x in diameter, predominantly 56-70 \x; spines 1 1-36 \x 

 in length. Sexual reproduction unknown" (Johnson, loc. cit.). 



On apples, United States. 



Distinguishable from Mindeniella spinospora by its distinctly smaller 

 zoospores, smaller sporangia, and consistently bent. "chicken-leg"-like, 

 basal cell. 



