104 Bulletin 313 



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

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



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

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



CoLLETOTRiCHUM cixcTUM Ston. (= Gloiuerella 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 /a; septse present. 



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

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



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

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

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

 scattered, superepidermal, erumpent, dark, setse, sparingly septate, 

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

 straight or occasionally slightly cin^ved, 16-28 x 4-6 /a. 



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

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



CoLLETOTRiCHUM GRAMiNicoLUM (Cesati) Wilson.* — Causcs cir- 

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

 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 scab 

 (Fusarinm culmorum Smitli) except that there is no pink over- 

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

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

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

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



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



COLLETOTRICHUM CYCLAMENS Hals. (= Glomerella rufomacii- 

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

 greenhouse. Causes prominent spots. Acervuli on both surf-aces 

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

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

 slender, setse free, short, and rigid. 



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



*Syn. Colletofrichum cereale Manus. 



Colletotrichum sangiiineum E. & H. 

 Co He to trie hum frotni Jennings. 

 CoUetotrichum lineola paehyspora E. & K. 



