BLASTOCLADIALES 691 



omously, pseudodichotomously, or sympodially, cylindrical through- 

 out, holdfasts stout, branched, setae absent, entire thallus 500-1500 

 (i. long; sporangia spirally arranged, terminal or intercalary and sessile 

 or on short lateral branches, cylindrical, subcylindrical, predominantly 

 distinctly long-fusiform, basally truncate, with a prominent apical papil- 

 la, 45-100 [x long by 17-40 [x in greatest diameter; zoospores spherical 

 or slightly elongate, posteriorly uniflagellate, 7.5-10 [x in diameter, 

 emerging in a compact column before dispersal; resting spores broadly 

 fusiform or ellipsoidal, with a pronounced apical beak and a truncate 

 slightly elongate base, 30-53 [x long by 15-30 [x in greatest diameter, 

 contents with globules, wall moderately thick, brown, punctate, occur- 

 ring alone or with the sporangia, at maturity falling out of the thin- 

 walled enveloping case, germination not observed. 



Forming a fairly loose turf on the surface of the substratum or mixed 

 with other water molds in pustules. On fruits, Minden (loc. cit.), 

 Germany; twigs of Aesculus, Lund (1934: 42, fig. 19), Denmark; twigs 

 ofAesculussp., Sparrow (S.)( 1936a: 455, pi. 20, fig. 14), Great Britain; 

 fruit, Das-Gupta and John (1953: 168, fig. 4), rotting turnip, Lacy 

 (1955:208), India. 



Blastocladia ramosa Thaxter 



Bot. Gaz., 21 : 50, pi. 3, figs. 14-16. 1896 

 (Fig. 47 C-D, p. 682) 



Basal cell cylindrical, up to 400 fx long by 14-80 ;x in diameter, divided 

 distally dichotomously or subdichotomously into from two to several 

 secondary slightly tapering axes which branch and rebranch sympo- 

 dially or somewhat irregularly, holdfasts delicate, sparingly branched, 

 wall thin, smooth, setae absent, whole thallus delicate, with an open 

 ramose habit, up to 260-1000 fx high; sporangia terminal and subtermi- 

 nal, on short branches, either narrowly or broadly ovoid with a narrow 

 truncate base or broadly fusiform, 30-85 jx long by 7-24 jx in diameter, 

 papilla apical; zoospores ellipsoid to pyriform, 5-6 c 6-7 jx, posteriorly 

 uniflagellate; resting spores borne like the sporangia, broadly ovoid, 

 narrowly clavate or spatulate, with a rounded apex and a narrower trun- 

 cate base, 18-38 (x long by 1 1-28 (x in diameter, wall colorless or faintly 

 brown, slightly thickened, minutely punctate, germination not observed. 



