XENODOCHUS 



303 



Arthur records and names another species, X. minor, on 

 Sanguisorba latifolia, from Alaska. 



Xenodochus carbonarius Schlecht. 



Xenodochus carhonariv& Schlecht. in Linnsea, i. 237. pi. 3, f. 3. Cooke, 

 Handb. p. 489 ; Micr. Fung. p. 201, pi. 3, f. 29. Plowr. Ured. 

 p. 227. Sacc. Syll. vii. 751. 



Phraymidium carbonarium Wint. Pilze, p. 227. Fischer, Ured. 

 Schweiz, p. 406, f. 284. Sydow, Monogr. iii. 157, f. 67. 



^Ecidiospofes. Cseomata hypophyllous, on coloured spots, 

 elongated, large, erumpent and pul- 

 verulent on the nerves, petioles and 

 stems, roundish and scattered on the 

 leaves, bright orange-red or vermilion; 

 spores roundish to oblong, verruculose, 

 orange, 18 — 24 /x, in short chains. 



Teleutos'pores. Sori amphigenous, 

 often confluent with the cseomata, 

 roundish, soon naked, thick, large, 

 pulvinate, black ; spores elongated- 

 cylindrical, often curved, of 4 — 22 

 cells, rounded at both ends, strongly 

 constricted, smooth, dark-brown, 200 — 

 300 x 24—28 fi ; each cell with two 

 opposite germ-pores at the upper 

 margin, except the uppermost which 

 has one apical germ-pore ; pedicels 

 very short, persistent. The whole 

 chain is surrounded by a distinct sub- 

 hyaline membrane, which swells up considerably in lactic acid. 



On Sanguisorba officinalis. Not uncommon. June — Oc- 

 tober. (Fig. 229.) 



The teleutospore-cells of the Burnet Chain Rust mature from above 

 downwards, the upper ones being darkest and the lower ones often 

 colourless. There are no uredospores ; perhaps they are represented by 

 secondary secidiospoies. The distinctions of this species from the other 

 Phragmidieaj are quite sufficient to justify its generic separation. 



Winter assigns to the cseomata clavate paraphyses which I cannot find. 

 Distribution : Europe, Asia. 



Fig. 229. A', carbonarius. 

 Teleutospore x 360 ; upper 

 part of same, x 600. 



