384 (HUVSOMYXA 



Gardens, Glasuevin, Dublin, on Onddium varicomm and 0. Forbesii. 

 Others of the same character were also seen there by Sir Frederick Moore 

 ..11 Epidendrum viteUinum and Lycaste Skinneri. These tropical parasites 

 are imported with the plants, and occasionally spread to a small extent, 

 under glass, in this country. Persistent examination of such imports 

 would no doubt discover still others of the same kind. 



Chrysomyxa Rhododendri De Ban. 



JEcidium abietinum A. et S. Consp. p. L20 p.p. 

 Uredo Rhododendri DC. Flor. fr. vi. 86. 



Chrysomyxa Rhododendri De Bary, in Bot. Zeit. 1879, p. 809, pi. 10, 

 f. i_6. Sacc. Syll. vii. TOO. Fischer, Fred. Schweiz, p. 126. 



[.Er'nIinxjHii-cs. .Ecidia irregular, membranaceous, com- 

 pressed and elongated parallel to the mid-rib of the leaf (up 

 to 3 mm. long), erumpent on transverse yellowed zones, at length 

 irregularly torn, whitish; spores more or less ellipsoid, yellowish, 

 17 — 45x12 — 22 ^ : epispore thin, thickly verruculose except 

 for a smooth longitudinal stripe.] 



Uredospores. Sori almost always hypophyllous, on yellowish 

 or brownish spots, minute, roundish or oblong, scattered or in 

 small groups, at length pulverulent, orange ; spores in chains 

 with intercalary cells, irregular or oval, verruculose, orange- 

 yellow, 17 — 28 x 15 — 22 ijl, without perceptible germ-pores. 



[Teleutospores. Sori similar, in densely clustered groups, 

 brownish-red . spores single or in the centre of the sorus several 

 (4 — 6) superposed in a row, prismatic, 20 — 30x10 — 14 fj.: 

 epispore colourless, thin, but with an annular thickening at the 

 summit of the uppermost cell.] 



[iEcidia on leaves of Picea excelsa, August — October ;] 

 uredospores on Rhododendron hirsutum, Douglas Castle, Lanark- 

 shire, June, 1913 (D. A. Boyd). 



While this book was passing through the press, Mr D. A. Boyd kindly 

 communicated specimens of this most interesting find. It occurred in 

 small quantity, and only uredospores were observed. Description of the 

 other forms after De Bary. This parasite is very common in Switzerland, 

 in all parts where the Fir and the Alpine Boses occur together. The 

 teleutospores germinate in June or July and the spermogones and secidia 

 appear on the Fir leaves from that time onwards. The secidiospores can 

 at once infect the Bhododendron leaves, where the mycelium winters, 



