104 Bulletin 313 



long, rounded at tlie ends, straight or slightly curved, granular 

 prominent, central vacuole, 16-21 x 4 /i,. 



629. Infected stem of snapdragon. 630. Infected leaf of same. 631. Spores, 

 1/12. 632. Bristle, 1/12. 



CoLLETOTRicHUM ciNCTUM Stofi. (= Glomerella cincta (B, & C.) 

 S. & S., page 52). — On leaves of orchids. Causes a spotting and, in 

 severe cases, a dying of the foliage. Acervuli erumpent ; conidia 

 elliptical, 12-15 x 3-4 p.; septse present. 



633. Immature bristle, 1/12. 634. Mature bristle, 1/12. 635. Conidiophoros 

 and conidia, 1/12. 636. Spores from Catleya sp. 1/12. 



CoLLETOTRiCHUM GLCEOSPORioiDES Penz. — On shoots, leaves, Row- 

 ers and fruit oi citrus plants in greenhouses. Causes the "wither tip'' 

 on shoots, leaves and flowers and cankers on the fruits. Acervuli 

 scattered, superepidermal, erumpent, dark, setae, sparingly septate, 

 dark-colored, 40-90 x 5-6 /x; conidia cylindrical with roimded ends, 

 straight or occasionally slightly curved, 16-28 x 4-6 fx. 



637. Spores, 1/12, from two sources. 638. Formation of spores on mycelivm 

 in culture, 1/12. 639. Germinating spores, 1/12. 



CoLLETOTRicHUM GRAMiNicoLUM (Ccsati) Wilson.* — Causcs cir- 

 cular or ovoid spots on roots, stems, blades and spikes of rye, wlieat, 

 cats, barley, emmer, orchard grass, timothy, blue-grass and chess. 

 Causes premature ripening and shrivelling of the grain. Diseased 

 heads have very much the appearance of being attacked by .=cab 

 (Fusarium culmorum Smith) except that there is no pink over- 

 growth. Acervuli dark-brown or black; setse few or many, dark- 

 brown or black, 1-2 septate, 60-120 /* in length and 6-8 ix thick at 

 base; conidiophores very short, 12-6 x 1-2 ^; conidia spindle or boat- 

 shaped, 2 to several guttulate, 18-26 x 3-4 ^. 



640. Section through acervulus showing bristles and spores, 1/12. 



CoLLETOTRiCHUM CYCLAMENS Hals. (= Glomerella riifoniacu- 

 lans var. Cyclaminis P. & C). — On the leaves of Cyclamen in the 

 greenhouse. Causes prominent spots. Acervuli on both surfaces 

 of the leaves, brown; conidia oblong, linear, obovate, straight or 

 slightly curved, ends rounded, 12-15 x 4-5 /a; conidiophores long, 

 slender, setae free, short, and rigid. 



641. Bristle, 1/12. 642. Spores, 1/12. 



*Syn. Colletotrichum cereale Manus. 



Colletotrichum sanguineum E. & H. 

 Colletotrichum fromi Jennings. 

 Colletotrichum lineola pachyspora E. & K. 



