82 Bulletin 313 



AscocHYTA ALTH^iNA Sacc. & Bizz, — On the leaves of the holly- 

 hock. Causes more or less circular, brownish spots, often with 

 yellowish margins. Pycnidia brown, numerous, ostiolate; spores 

 emerging in white tendril-like masses, ovate to oblong, more or less 

 rounded at both ends, 1-septate, somewhat constricted at septum, 

 hyaline, 6-10 x 2.8-4 /x. 



469. Leaf spot. 470. Pycnidium, 2/3. 471. Immature and mature spores, 

 1/12. 



AscocHYTA LETiiALis* E. & B. (= MycosphcBrella lethalis 

 Stone, page 44). — On stems and petioles of Melilotus officinalis. 

 Causes peculiar irregular, dirty white, slightly raised brownish bor- 

 der, about 2-3 mm. in diameter. Pycnidia numerous, loosely 

 grouped, semi-erumpent, smooth, orbicular, convex, becoming con- 

 cave, brownish to black, ostiolate, 50-120 /x in diameter; spores ob- 

 long, cylindrical, obtuse at both ends, usually 1-, occasionally 2- 

 septate, or non-septate, or uni- or bi-septate, slightly constricted, 

 hyahne, 10-17 x 3.5-4.5 ix. 



472. Infected stem of Melilotus officinalis. 473. Pycnidia, 2/3. 474. 

 Spores, 1/12. 



AscocHYTA LYCOPERSici Brun. — On the foliage of greenhouse 

 tomato plants. Causes small brown, circular, spots which gradually 

 become larger, sub-circular or irregular and grayish, reddish or 

 brown in color and marked with delicate, black, more or less irregu- 

 lar concentric circles somewhat similar to the spots caused by the 

 early blight (Macrosporium solani E. & M.). Pycnidia few, minute, 

 black; conidiospores oblong, 1-septate, constricted at the middle, 

 hyaline, 8-10 x 2.5 fx. 



475. Infected tomato leaf. 476. Pycnidia, 2/3 477. Cross-section of pycni- 

 dium, 2/3. 478. Spores, 1/12. 



AscocHYTA RHEif E. & E. — On the leaves of rhubarb. Causes 

 reddish-brown, concentrically-zoned spots about 1 cm. in diameter. 

 Pycnidia brown, loose, beaked; spores oozing out in tendril form, 

 straight or curved, oblong-ovate, hyaline, 1- or 2-celled, constricted, 

 variable in size, the largest measuring 14.4 x 3.5 fx. 



479. Pycnidium, 2/3. 480. Spores, 1/12. 



AscocHYTA Pisi Lib. (= Mycosphcerella pinoides B. & B., page 

 44). — On leaves, fruit, and stems of cultivated peas. Causes 

 circular, yellowish spots of various sizes and brown margins. Pyc- 



*Syn. A. Caulicola Lamb. 

 tSyn. Phyllosticta rh-ei. 



