88 Bulletin 313 



Septoria cerastii Rob. & Desm. — On the leaves and stem of 

 Cerastium vulgatum. Causes spots which are pale yellow, becoming 

 ashy-gray at maturity. Pycnidia globose, lenticular, black ostiolate, 

 80 IX in diameter; spores escaping in whitish tendrils, hyaline, long, 

 straight or slightly curved, 30-40 x 1 ft. 



514. Pycnidia, 2/3. 515. Spores, 1/12. 



Septoria chrysanthemi Allesch. — On the leaves of the Chrysan- 

 themum. Causes brown spots of various sizes and frequently a 

 dying of the margins. When severe the leaves wither and fall. 

 Spots ochre-colored with dark margins ; pycnidia globular with 

 short beak; spores long, straight or slightly curved, hyaline, some- 

 times obscurely septate, 32-57 x 1.5-2 fi. 



516. Infected leaves of Chrysanthemum. 517. Pycnidia, 2/3. 518. Imma- 

 ture spores, 1/12. 519. Mature spores, 1/12. 



Septoria convolvuli Desm. — On the leaves of Convolvulus ar- 

 vensis. Causes circular, sometimes confluent, reddish-brown spots 

 becoming smoky-brown and finally whitish. Pycnidia minute, brown 

 erumpent; spores long, straight or slightly curved, 3-5 septate, 35- 

 50 X 1.5 fi. 



520. Infected leaf of Convolvulus arvensis. 521. Pycnidia, 2/3. 522. Cross- 

 section of pycnidium, 2/3. 523. Spores, 1/12. 



Septoria cornicola Desm. — On the leaves of Cornus. Causes 

 scattered, depressed, orbicular spots 100-110 mm. with dark purple 

 margins. Conidia cylindric, curved, obsolete 2-4 septate, hyaline, 

 35-40 X 2-2.5 fi. 



524. Infected leaf of Cornus si>. 525- Pycnidia, 2/3. 526. Spores, 1/12. 527. 

 Germinating spores, 1/12. 



