350 MELAMPSORA 



Uredospores. Sori hypophyllous, minute, \ mm., somewhat 

 pulvinate, pulverulent, spots obsolete; spores oval, oblong or 

 obovate, rarely round, 15 22 x 10 — 15 fi\ epispore about 2/i 

 thick, covered with stout spines; paraphyses distributed through- 

 oui the sorus, elongated-clavate rather than capitate, 40 — 45 x 

 S—I7fi, with a thick wall (3—9^). 



Teleutos pores. Sori hypophyllous, minute, \ — 1 mm. diam., 

 covered by the epidermis, dark-brown; spores prismatic, rounded 

 at both ends, 40—60x7 — 12^; epispore thin (1 — 2 //,), not 

 thickened above, with a scarcely evident germ-pore. 



Cseomata on Larix europaea; uredo- and teletitospores on 

 Populvs alba, P. tremula, rarely P. balsamifera, September, 

 October. 



The description is after Klebahn. The teleutospores germinate after 

 a winter's rest. Though Plowright records that he could obtain no result 

 " by placing the germinating teleutospores of M. tremulae on young larch 

 trees" {I.e. p. 241), the truth of the heterceeism has been abundantly 

 demonstrated by Hartig, Klebahn and Fischer. Plowright mentions that 

 Prof. Trail had found these two forms growing in company near Aberdeen ; 

 and the meaning of his failure is simply that he was using one of the 

 other Melampsorae that grow on P. tremula. It has been suggested, but 

 not proved, that M. pinitorqua is itself only a biological race, and there 

 are also M. Magnusiana (Klebahni), and M. Rostrupii which may come 

 under the same categoi'y ; see p. 353. 



(2) Melampsora pinitorqua Rostr. 



( 'deoma pinitorquum A. Braun, in Monatsb. Berl. Akad. 1863, p. 624. 



Melampsora pinitorqua Rostr. Tidsskr. f. Skovbrug, 1889, xii. 177. 

 Fischer, Ured. Schweiz, p. 499. Yorkshire Fungus Flora, p. 183. 

 Massee, Text-book of Fungi, f. 22, 98 ; Text-book of Plant 

 Diseases, p. 235, f. 60 ; Uis. Cultiv. Plants, p. 325, f. 98. 



jEcidiospores. Creomata erumpent through the cortex of 

 young shoots, solitary, linear, reaching 20 x 3 mm., reddish- 

 orange ; spores roundish or oval, pale reddish-yellow, 14 — 20 x 

 13 — 17 /J,, or oblong, 22 x 10/x.; epispore about 2 p, thick, deli- 

 cately verruculose. 



Uredospores. Sori hypophyllous, on spots which show yellow 

 chiefly on the upper side, solitary or in groups, often scattered 

 over the whole surface, scarcely \ mm. wide, pulvinate; spores 



