PHOMA. 



467 



leaved trees, but details in regard to their parasitism are 

 wanting. 



Ph. Hennebergii Kiihn.^ Brown-spot of wheat-ears. This 

 produces, on the glumes of wheat, brown spots with projecting 

 pycnidia from which unicellular conidia emerge. The grains of 

 attacked ears shrivel up and become spotted, while the value 

 of the chaff as fodder is much diminished. Whole fields may 

 be attacked, showing marked discoloration, and producing but 

 few healthy ears.^ The fungus may also 

 appear on the leaves and produce pycnidia. 



Ph. lophiostomoides Sacc.^ Lopriore 

 regards this as a parasite on cereals, but 

 Cavara looks on it as saprophytic on the 

 dead plants. 



Ph. ampelinum De Bary {Sphaceloma 

 ampelinum De Bary). Anthracnose of the 

 Vine.* The mycelium of this fungus can 

 penetrate into leaves, green bark, or fruit, 

 and kills the tissues. Spots are first pro- 

 duced, then enlargement of the neighbour- 

 ing tissues takes place, causing the spots 

 to appear as if sunk in depressions, and 

 reminding one of hail-wounds. On leaves 

 and grapes, the spots are sharply defined, 

 at first dark- brown, later with greyish 

 centres and dark-brown margins. In the 

 later stages the dried-up spots may drop out of the leaves. 



Anthracnose, or " birds-eye rot," constitutes one of the dreaded 

 vine diseases of America and Europe, so that it has received 

 much attention, both as to its life-history and remedial measures ; 

 as yet however with but partial success. Copper sulphate 

 solutions seem to be fairly successful remedies, as shown from 

 results of the many experiments recorded in the Joiirnal of 



^Kuhn, Hedwigia, 1877, p. 121; also in 'Rahenhorst's Fungi europ. No. 2261. 

 Frank, Zeitsch. fur PJianzenkrankheiten, III., 1893, p. 28. 



^Eriksson (Mitthl. der h. Landb. Akad. Stockholm, 1890) records a case of 

 this kind, but the conidia are drawn two-celled as in a Diplodina, whereas 

 Kiihn's original drawings have only one-celled conidia. 



3 Cavara et Eriksson, Zeitsch. f. PJlanzmb-ankheiten, ill., p. 23. 



* Goethe, Mitthl. iib. den. schwarzen Brenner d. Rehen. Leipzig, 1878. Cornu, 

 Bullet, de la Soc. botan. de France, 1878. Prillieux (idem), 1879. Eathay, " £>er 

 Black-rot," 1891. Scribner, Report of U.S. Amer. Dept. of Agriculture, 1886. 



Fig. 294. — Phoma ampeli- 

 num. Brown concave spots 

 on shoot and berry of Vitis. 

 (v. Tubeuf del.) 



