GERCOSPORA. 515 



C. resedae Fuck.^ This fungus is the cause of a garden 

 mignonette disease very common in America and Europe. It 

 causes little depressed spots with brownish or yellowish borders, 

 which begin as reddish discolorations of the leaf. The leaves 

 gradually wither and dry up, so that the flowers suffer. The 

 mycelium grows inside the leaves, and gives off tufts of conidio- 

 phores through the stomata. The conidia are elongated, septate, 

 and spindle-like or club-shaped. Spraying with Bordeaux 

 mixture was found to give good results. 



C. cheiranthi Sacc. produces roundish leaf-spots on wall- 

 flower, and, if severe, causes death of the leaves and premature 

 defoliation of the plants. 



C. rosaecola Pass. This causes leaf-spot on cultivated and 

 wild roses in the United States. The first indication of disease 

 is the appearance of black spots with reddish margins. The 

 conidiophores emerge from the stomata in tufts, and carry long 

 obclavate conidia. 



C. angulata Wint. is one of the causes of leaf-spot on 

 currant, and occurs often in company with Septoria ribis. (U.S. 

 America.) 



C. violae Sacc. occurs on leaves of Viola odorata. 



C. malvarum Sacc. On species of Malva. 



C. althaeina Sacc. On hollyhock in the United States. 



C. neriella Sacc. causes leaf-spot on Nermm Oleander. 



C. Bolleana (Thiim.) produces olive-brown spots on leaves and fruits 

 of the Fig, injuring the crop. 



C. capparidis Sacc. On Cappa/ris spinosa in Italy. 



C. gfossypina Cooke is given by Atkinson as a fungus frequently present 

 on diseased plants of cotton.^ 



Saccardo records over 230 species of Cercospora, most of which cause 

 spotting of living or fading leaves of many plants, e.g. Phaseolus, Lupinus, 

 TrifoUum, Vicia, Gleditschia, Solanum nigrum. Datura, Riciniis, Ampelopsis, 

 Liriodendron, Tilia, Rosa, Potentilla, Rubus, Cydorda, Ptelea, Rhamnus, 

 Euonyrrvm, Ailanthus, Rhus, Samhucus, Viburnum, Olea, Syringa, Moras, 

 Fraxinws, Coffea, Idgustrum, Mercurialis, etc. 



Heterosporium. 



Conidiophores simple or branched. Conidia olive, oblong, 

 pluriseptate, and with a spiny or warty outer coat. 



iFairohild in Report of Section of Vegetable Pathology for 1889, U.S. Dept. 

 of Agriculture. 



''Botanical Gazette, 1891, p. 61. 



