Apr. 8. 1918 Relation of Soil Fungi to Potato Diseases 89 



{14, p. 242-244) that there was no doubt in the mind of the writer as 

 to its identity. 



Habitat: On rotted tubers of Solanum tuberosum in New York {14, p. 

 242). Isolated four times from Idaho soils as follows: Twice from 

 group A and once each from group C and sample i . 



Fusarium discolor var. triseptattun Sherb. {14, p. 230-240, pi. 4, fig. 5-6; pi. 5, fig. 

 10; text fig. iWi, 42; 22, drawings Jig, 320). 



The strain isolated differed from an authentic culture of the species 

 (furnished by Dr. L. L. Harter) by having slightly smaller conidia. 

 Otherwise the organism isolated appeared to be identical with that 

 originally described by Sherbakoff {14, p. 23^-240). In his Fusaria 

 Autographice Delineata, Wollenweber {22) considers F. discolor var. tri- 

 septatum a synonym of F. discolor Ap. and Wollenw., which in turn he 

 makes a synonym of F. samhticinum Fuch. 



Habitat: On rotted tubers of Solanum iuherostim, together with F. 

 coeruleum, Long Island, N. Y. (14, p. 259). Isolated four times from 

 Idaho soils, twice each from samples i and 3 



Fusarium subpalliduxn Sherb. {14, p. 230-234; pi. 5, fig. 12, text fig. 39; 22, drauing 

 326). 



The form isolated was identified by comparing with a culture of the 

 original strain (culture furnished by Dr. L. h. Harter), with which it 

 was found to be identical in every important particular. 



Habitat: On superficial dryrot of potato tubers from Louisiana {14). 

 Isolated twice from Idaho soils from group A. 

 Fusarium aridum, n. sp. (Pi. B, 1-3; fig. 2, Q). 



Conidia in aerial mycelium, pseudopionnotes, and sporodochia, slightly 

 curved, typically broader in the upper half of their length, usually sud- 

 denly constricted at the apex, slightly pedicillate, typically 3-septate, 

 averaging 27 by 4.2 (18 to 36 by 3 to 5) /x; 1,2, and 4-septate usually 

 present, the 4-septate rare; aerial mycelium typically well developed, 

 white at first, becoming pink to vinaceous; substratum on steamed- 

 potato plug, often vinaceous to Vandyke red; on Irish potato agar with 

 10 per cent of glucose vinaceous-purple to carmen; steamed rice shades 

 of yellow and brown; sporodochia and pseudopionnotes, salmon-orange 

 to light-orange. Chlamydospores not observed. 



Habitat: Isolated once from Idaho soils, from group B. When inocu- 

 lated into potato tubers, a slight decay resulted, which bore a close 

 resemblance to the type of decay produced by F. trichothecioides. The 

 decay proceeded downward into the tuber from the point of inoculation 

 for about }i inch during the first 10 days, but though kept at tempera- 

 tures varying from 5° to 35° C. for several weeks, failed to proceed far- 

 ther. The writer therefore does not consider it capable alone of causing 

 extensive rotting of potato tubers. 

 41812°— 18 2 



