ON COMPOSITA 133 
been found (Gibson, 1904, p. 188). If that is so, the disease can easily 
be kept in check by rigid cleanliness and by spraying at intervals with 
very dilute Bordeaux mixture or, better still, potassium sulphide solution. 
Remove and burn all attacked leaves as soon as seen, water carefully with- 
out wetting the leaves, choose resistant varieties (e.g. “‘ October Sun” and 
“ William Tricker” are said to be immune), and there will be little fear 
of an epidemic of the disease. 
DistRiBuTION: Europe, Japan, North America, Australia. 
5. Puccinia Leucanthemi Pass. 
Puccinia Leucanthemi Pass. in Hedw. 1874, p.47. Sacc. Syll. vii. 705, 
Sydow, Monogr. 1. 116, f. 95. 
P. Asteris var. Chrysanthemi-Leucanthemi Massal. in Bull. Soc. Bot. 
Ital. 1900, p. 258. Sacc. Syll. xvi. 297. Trans. Brit. Myc. Soc. 
iii, 224. 
Teleutospores. Sori amphigenous, generally hypophyllous, 
often also on the petioles, scattered 
or often circinate on indistinct spots, 
or confluent into compact cushions 
2—5 mm. wide, reddish-brown; spores 
oblong or subclavate, somewhat 
rounded or more often narrowed at 
the apex, much thickened above (up 
to 14), constricted, tapering down- 
wards, smooth, yellowish, 40—70 x 
1424; pedicels hyaline, thick, \ 
about as long as the spore. 
Fig. 85. P. Leucanthemi. 
On Chrysanthemum Leucanthe-  Teleutospores, from an ori- 
ginal specimen issued by 
mum. Very rare. Lamorna. Cove, Passerini. 
Cornwall, September, 1906 (F. J. 
Chittenden). (Fig. 85.) 
Only recorded for Britain and Italy. The similarity of the spores to 
the teleutospores of Puceinia Afcidii-Leucanthemi Fisch., which has its 
eecidiospores on C. Leutanthemum and its teleutospores on Carex montana, 
seems to indicate that this is one of those instances, like P. fusca and P. 
Pruni-spinosae, which give us a glimpse into the mode of evolution of 
the Uredinales. 
