374 



IIYAI.ol'SoRA 



possible alternate hosts. This is in itself improbable and is 

 inconsistent with Arthur's suggestion that of the two kinds of 

 nrcdospoivs the first kind represents aecidiospores. 



1. Hyalopsora Aspidiotus Magn. 



Uredo Polypodii Schrot. Krypt. Flor. Schles. iii. 374. Plowr. Ured. 



p. 256 p.p. Sacc. Syll. vii. 857 p.p. 

 U. Asj,iili',/n.< Peck in Ann. Rep. X. Y. State Mus. xxiv. 88. 

 Melampsorella Aspidiotus Magn. Ber. Deutsch. Bot. Gesell. xiii. 288. 

 Pucciniastrum Aspidiotus Karsten, Bidr. Finl. Nat. Folk, 1879. xxxi. 



1 13. 

 Hyalopsora Aspidiotus Magn. Ber. Deutsch. Bot. Gesell. 1901, xix. 



582. Arthur, N. Amer. Flor. vii. 112. 

 H. Polypodii-Dryopteridis Magn. in Hedwig. 1902, p. 224. Fischer, 



Ured. Schweiz, p. 472, f. 308. 



Uredospores. Sori amphigenous, scattered, small, round. 

 up to | mm., golden-yellow, without a peridium, dehiscing 

 irregularly, often seated on yellowish spots; spores oblong or 

 ellipsoid, of two kinds, (1) thick-walled (2| — 3^/x), with very 



Fig. 279. II. Aspidiotus. Part of frond of P. Dryopteris, showing uredo-sori, 

 nat. size ; three spores, all from the same sorus (Scotland). 



faint, hardly perceptible warts, 36 — 72x30 — 40 p. with 6 — 8 

 scattered germ-pores, (2) thin-walled (about li f. L ), covered 

 uniformly with very faint scattered warts, 28 — 40 x 16 — 26 p, 

 with four indistinct equatorial germ-pores; paraphyses few. 



Teleutospores. In the epidermal cells, often filling them 

 completely, roundish or irregular, flattened where they are in 

 contact, sometimes arranged in two layers, about 25 p. high, 

 21 — 35 p or more wide, divided by vertical septa into 3 — 5 



