PLEOSPORA 243 



truding, elongated, thickened upwards ; asci cylindrical-clavate, 

 8-spored ; paraphyses slightly clavate ; spores elliptic-fusi- 

 form, i-septate, rarely 2-3-septate, yellowish-brown, 22-32 x 



6-9 jX. 



No remedial measures suggested. 



Cavara, Zeitschr. Pflanzenkr., 3, p. 16 (1893). 



F. Spores coloured, more than i-septate. 



PLEOSPORA (Rabenh.) 



Perithecia immersed or bursting through the epidermis, 

 membranaceous ; asci clavate, 4-8-spored ; spores elongated, 

 coloured, muriform. Conidia, pycnidia and spermogonia 

 sometimes present. 



Chicory disease. A troublesome disease which attacks 

 chicory plants in France, more especially those that are culti- 

 vated for seed. The injury is caused by Pleospora albicans 

 (Fckl.), and appears under the form of yellowish-grey spots on 

 the lower portion of the stem. These spots gradually increase 

 in size, and at a later stage appear on the secondary branches 

 and on the leaves. These spots become whitish and are 

 bordered by a dark line. At a later stage minute black dots 

 the perithecia appear on these pale spots. If the weather 

 is moist and warm, the disease spreads rapidly, and the plant 

 is destroyed. If, on the other hand, a dry spell of weather 

 sets in, the disease is checked, and a certain amount of seed 

 may be produced. 



A conidial Phoma stage of fruit is first produced, followed 

 during the winter, on the dead plant, by ascigerous fruit. 



Phoma form. Perithecia subglobose, sunk in the tissue of 

 the host, the short mouth just protruding through the epi- 

 dermis, conidia cylindric-oblong, hyaline, mixed with 

 minute, curved spermatia. This form is Phoma albicans 

 (Rob. and Desm.). 



Ascigerous stage. Perithecia sunk in the matrix, depressed- 

 globose, asci clavate, 8-spored, spores elliptic-oblong, yellowish- 

 brown, 5-7-transversely septate, with very few vertical septa. 



The ascigerous form of fruit is produced on the dead plant 

 during winter. 



Prillieux, Bull. Soc. Myc. France, 1896, p. 82. 



