172 PUCCINIA 



garden mint ; perhaps those forms which are without it may hereafter be 

 separated. l>ut it has occurred on all the hosts mentioned above except 

 mum ami M. rotundifolia ; it may, however, according to Sydow, be 

 mcnly facultative. The formon C. < linopodium really shows less difference 

 from that on Mentha aquatica than those on .species of Mentha do from one 

 another. But Cruchet was unable to infect any one of the four M. arvensis, 

 M. ,/,/,/, /tint, M. silvestris, C. C(inopodiu7n, except by spores from the same 

 species. As the result of his experiments, he divides /'. Menthae into 

 eight biological races, as it occurs on Mentha and CaZamintha; and the 

 form "ii Origanum, is also biologically distinct. The Australian form of 

 /'. Menthae, which is an introduced species on M. Pulegium and M. laxv- 

 flora, has no known aecidiospores, but occasional mesospores. Nothing 

 seems to be known about the form on Ajuga reptans mentioned by 

 Plowright, from Johnston's Flor. Berwick. 



In garden mint (J/, viridis) the mycelium of the aecidial stage is spread 

 throughout the whole plant, even in the rhizome ; Klebahn was aide to 

 trace the hypha? in some cases nearly up to the growing point. It lasts 

 for several years at least ; a bed of mint infested with it should be rooted 

 tip ami burnt ; there is no cure for the disease, although I have found that 

 cuttings taken from some of the more distant healthy-looking shoots and 

 planted i/.tiiekere grow up without the parasite. The mycelium of the two 

 other stages is purely local. I have known the secidia to occur for several 

 years in a garden without being followed by uredo- or teleutospores so far 

 as could be seen, and vice-versa, in another case, these spores occurred but 

 no secidium was ever noticed. 



Distribution : Europe, Asia, Africa ; the American and 

 Australian teleutospores are more strongly warted. 



44. Puccinia caulincola Schneid. 



Puccinia caulincola Schneid. in Jahresb. Schles. Gesell. 1870, p. 120. 



Sydow, Monogr. i. 301. Fischer, Ured. Schweiz, p. 172, f. 133. 

 P. Xrhwideri Schrot. in Herb. Schles. Pilze, no. 448. Plowr. Ured. 



p. 201. Sacc. Syll. vii. 677. 



Teleutospores. Sori on the stems and petioles, rarely on 

 the leaves, scattered, occasionally confluent, minute, roundish 

 or elongated, long covered by the bullate epidermis, at length 

 pulverulent, black, then cinnamon-brown ; spores ellipsoid, 

 rounded at both ends, apex sometimes thickened in a papilli- 

 form fashion, rather constricted, smooth, pale-brown, 24 — 33 

 x 15 — 24 fx: pedicels hyaline, thin, rather long, not very 



