LEPTOMITALES 901 



MINDENIELLA Kanouse 

 Amer. J.Bot., 14: 301. 1927 

 (Fig. 72 A-F, p. 902) 



Thallus consisting of a narrowly clavate occasionally cylindrical basal 

 cell anchored to the substratum by a system of branched holdfasts; 

 zoosporangia smooth-walled or spiny, borne on short narrow thick- 

 walled pedicels which arise directly from the surface of the basal cell; 

 zoospores of the secondary, biflagellate type, completely formed in the 

 sporangium, contents bearing numerous globules, emerging through an 

 apical pore; resting spore apogamously developed, thick-walled, entire- 

 ly filling its spiny-walled container, germination not observed. 



On decaying rosaceous fruits in fresh water. 



Observations on Mindeniella by Sparrow and Cutter (1941) showed 

 that the zoospores (Fig. 72 C) of this fungus are biflagellate and, hence, 

 that the genus should be placed in the Leptomitales. 



KEY TO THE SPECIES OF MINDENIELLA 



Basal cell clavate or cylindrical; zoospores 8-15 by 6-10 \j. 



M. spinospora, p. 901 

 Basal cell consistently bent-clavate, or inverted boot-shaped; zoo- 

 spores 5-9 by 3-7 \l M. asymmetria, p. 903 



Mindeniella spinospora Kanouse 



Amer. J. Bot., 14:301, pi. 34, 1927 

 (Fig. 72 A-F, p. 902) 



Basal cell narrowly clavate, rarely cylindrical, predominantly un- 

 branched but occasionally divided apically into two blunt lobes, 200- 

 850 \x long by 100-200 \x in greatest diameter, about 30-40 \i in diameter 

 at the base, from which emerges a system of branched holdfasts, wall 

 thick, occasionally with exfoliated material on its outer surface, contents 

 coarsely granular; zoosporangia arising in most cases from the upper, 

 expanded part of the basal cell, occasionally lower down, borne on 

 short, narrow, thick-walled pedicels from which they are separated by 

 a cellulin plug, predominantly narrowly and symmetrically clavate or 

 ovate, occasionally slightly constricted in the mid-region, somewhat 



