74 Bulletin 313 



tion, and the other internally as hyaline, thin-walled, oblong-cylin- 

 dric, endoconidiospores, narrow in central part, 16-30 x 4-9 fx. 



400. Infected sweet potato. 401. Pycnidia embedded in the surface tissue 

 of the sweet potato. 402. Mature pycnidium, 2/3. 403. Tip of same, 1/6. 

 404. Pycnospores, 1/12. 405. Same, germinating, 1/6. 406. Chlamydospores, 

 1/6, 1/12. 407. Germinating chlamydospores, 1/6. 408. Endoconidiophores 

 with emerging endoconidia, 1/6. 409. Endoconidia, 1/12. 410. Endoconidia 

 germinating, 1/6. 411. Base of immature pycnidium broken open, 1/6. 



Vermicularia circinans* Berk. — On the scales of bulbs of 

 white onions. Spots usually orbicular; pycnidia concentrically ar- 

 ranged, very small and covered with long spines ; conidia cylindrical, 

 elongated, curved, rounded at the tips. 



412. Infected onion bulb. 413. Pycnidium, 2/3. 414. Bristles, 1/12. 415. 

 Bristles arising from pseudoparenchj-ma, 1/12. 416. Spores, 1/12. 



Vermicularia dematium (Pers.) Fr. — On Polygonum avicu- 

 lare and also reported on asparagus and in Europe on ginseng. 

 Pycnidia conic and depressed, erumpent, superficial, frequently con- 

 fluent, 80-120 [x, more or less covered with black spines with pale 

 tips measuring 150-200 x 5 /a; conidia, elongated, cylindrical, 

 slightly curved, rounded tips, 20 x 4-6 /*. Usually a saprophyte but 

 frequently a parasite. 



417. Pycnidium, 2/3. 418. Spores. 1/12. 



FusicoccuM viticolum Reddick (^ Cytosporella viticolum Sh.l. 



On stems and fruits of grapes. Causes the "dead arm" disease of 



the stems resulting in the wilting and dying of the vine ; also causes 



a rotting of the ripe or nearly ripe fruit which is very similar to the 



black rot (Guignardia hidwellii). Pycnidia, small, brown and of 



many chambers, ostiolate but frequently rupturing. Spores emerg- 



mg in black tendril-like masses, hyaline or smoky, non-septate, more 



or less fusoid, sometimes curved, 6.6-13.3 x 3-6.3 /a. 



419. Infected cane of grape showing spore tendrils. 420. Cross-section 

 of pycnidium, 2/3. 421. Same, 1/12. 422. Spores, 1/12 from two sources. 

 423. Germinating spores, 1/12. 



Phomopsis vexans (Sacc. & Syd.) Harter (= Phyllosticta hor- 

 torum Speg., page 66) . — On the leaves, stems and fruit of the egg- 

 plant. Causes leaf spot, stem and fruit rots. Pycnidia loosely 

 grouped, black, beaked, flattened or irregular in shape, buried but 

 becoming erumpent, 60-200 fx. broad on leaves and stem, 120-350 /u 

 broad on fruit; conidiophores simple, short, straight or slightly 



♦Reported by J. C. Walker as Colletotrichum circinans (Berk.) Vogl. Meet- 

 ing of the American Phytopathological Society, New York, Ober. 27-30, 1916. 



