522 THE FUNGI WHICH CAUSE PLANT DISEASE 



The cause of leaf spots of tomato. It was noted in New Jersey 

 about 1893 »" and in Ohio in ISQG.^'^ It is one of the serious 

 tomato pests. 



S. lactucae Pass.^^"* 



Spots irregular, brownish, angulate, sometimes destroying the 

 entire leaf, pycnidia minute, punctiform, scattered, 90 n in 

 diameter, conidia filiform, straight or curved, 25- 

 30 X 1.7-2 M- 

 On lettuce. 



S. consimilis E. & M.'* 



Distinguishable from the preceding by the more 

 indefinite spots, slightly larger pycnidia (90-100 m) 

 and longer conidia (30-45 x 2-2.5 m)- It causes 

 brown spots on lettuce leaves. 



Fio. 36i.-Spores S. armoraciae Sacc.» 



of s. lycopersici. Spots irregular, ochraceous; pycmdia puncti- 

 form, grouped in the center of the spot, 60 n; 

 conidia filiform, curved, 15-20 x 2-2.5 ju, 1 to 3-septate. On 

 horseradish causing leaf spot. 



S. antirrhini Desm. attacks the snapdragon severely.*''' 



S. rosse Desm. is on rose; 



S. hydrangeas Bizz. on cultivated hydrangea; 



S. iridis C. Mass. on Iris. 



S. cyclaminis Dur. & M. on cyclamen. 



S. sedi West. 



Epiphyllous; spots circular, gray to gray-brown; pycnidia mi- 

 nute, numerous, brown, scattered, erumpent; conidia cylindric, 

 straight or curved, 5-guttulate; cirri white. On cultivated Sedum. 



S. hederse West, is on Hedera; 



S. rostrupii Sacc. & Syd. and S. varians Jaff. on chrysanthe- 

 mum; as is also: 



S. chrysanthemella Cav.**' ^"' Spots ochraceous, dark mar- 

 gined; pycnidia epiphyllous, punctiform; conidia 40-50 x 2.5-2 m, 

 obscurely septate. 



It causes damping off of chrysanthemum cuttings and spotting 

 of the leaves."' 



S. dianthi Desm.^* 



Spots yellowish, oblong, roundish or irregular; pycnidia globose, 



