468 FUNGI IMPERFKCTI. 



Mycology ami tlie bulletins and reports of the American experi- 

 mental stations. (Compare also (/loeosporium avipehypliagn.iri 

 (Pass.) p. 484.) 



Ph. betae Frank.^ The younger leaves of well-developed 

 heet-root liecome black, and the disease extends into the root. 

 Mycelium tills the diseased parts and penetrates into healthy 

 tissues. Tycnidia are developed on the diseased spots. The 

 fungus is no relation of Sjwridcsmivm 'putrcfacicns, a form to 

 which a root-ri)t is ascribed by Frank. It is however proljably 

 identical with Prillieux's Phyllostida tahifica. Kriiger found 

 the disease so common, that in many localities as many as 80 per 

 cent, of the plants were destroyed. Sorauer regards the root-rot 

 of beet to be sometimes caused by PJioma, sometimes by 

 Sjwridesvmtm, perhaps in some cases by both together. 



Ph. sanguinolenta Rostr.^ attacks carrot plants in their first 

 year, causing greyish-brown depressed spots on the bulbs with- 

 out however appearing to be very injurious to them. When 

 the seedlings are planted out in spring, the mycelium 

 extends into the stem and causes the umbel to wither at 

 flowering so that no seed is formed. Pycnidia are developed 

 from all attacked spots and give off conidia as red tendril-like 

 bodies — hence the species-name. Certain varieties of carrot 

 apjiear to resist attack by this parasite better than others. 



Ph. solani Hals. This causes damage to the egg-plant 

 {Solanum melongena).^ Young plants die off on the hot-beds, 

 their stems dying near the earth and shrivelling up. The 

 pycnidia of this Phoma appear on the killed parts. 



Ph. cydoniae Sacc. has been reported as injurious to quince 

 trees. (U.S. America.) 



Many species cause leaf-spot diseases. Some of the more 

 important British and American species are : 



Ph. pinastrella Sacc. On Pinux syJcestria and others. (Britain.) 



Ph. strobi (B. et Br.). On Pinus Sirobus. (Britain.) 



Ph. taxi (Berk.). On yew. (Britain.) 



Ph. Candollei (Berk, et Br.). On box. (Britain and U.S. America.) 



Ph. sorbi (Lascli.). On leaves of Ppnis Attmipana.' (Britain.) 



'Frank, Zeil-sch. /. Pjlanzenkrankheiteii, in., \>. 90, and Jknt.sr/u' laudw. Pr. 

 No. 89, 1893. Kriiger, ZcM-ich. f. Pflan-enkranUidtcn, iv., 1894, p. 195. 



'•^Described and figvu-ed l)y Halsted in Bulletin 91, N. J. A<jric. Exper. 

 Station. 1892. 



