356 MELAMPSORA 



/. ythea Lini Berk.; Cooke, Eandb. p. 532; Micr. Fung. p. 222, 

 pi. 8, f. l<;:, t. 



Melampsora Lini Desm. PI. Crypt, no. 2049. Plowr. [Jred. p. 237. 

 5 cc. Syll. vii. 588. Fischer, (Jred. Schweiz, p. ~> ( >7. McAlpiue, 

 Rusts of Australia, p. L92, f. 236 and pi. I. i. 36. 



Spermogones ) ^ ^^ 

 mcidiospores J 



Uredosj i< u-r.--. Sori amphigenous and on the stems, small, 

 scattered, roundish or oblong, flatly pulvinate, subepidermal, 

 (?at first covered by a parenchymatous peridium, Fischer), 

 orange; spores roundish to ellipsoid, echinulate, orange-yellow, 

 16 — 24 x 12 — 17 /Lt; paraphyses not numerous, hyaline, strongly 

 capitate, much thickened above, 20 — 25 /x diani. 



Y'il'. 200. M. Lini. a. teleutospores ; b, plan of same ; c, paraphysis 

 and two uredospores. On L. catharticum. 



Teleutospores. Sori similar, but confluent, chiefly on the 

 st tins, subepidermal, reddish-brown, at length black and shining; 

 spores prismatic, 35 — 60x7 — 10 fM) epispore thin, yellowish- 

 brown, rather thickened above and darker. 



On Linum catharticum. 

 (Fig. 266.) 



June — October. Not uncommon. 



Forms of Melampsora Lini occur widely on many species of Linum and 

 have usually been regarded as identical. That which often acts as a very 

 destructive parasite wherever the common Flax is cultivated has consider- 

 ably wider teleutospores (17 — 20^, McAlpiue) and attempts to infect 

 L. usitatissimum from L. catharticum have uniformly failed; it is therefore 

 considered by some as a biological race or even species = Melampsora 

 liniperda Kornicke (Centralbl. f. Bakter. 1911, 2. xxxii. 278). Teleuto- 

 spores of this have been described as much as 80 /x long. Fromme (1912) 

 has recently described spermogones and a-cidia to this form on cultivated 



