ON WILLOW 341 
19 w; epispore 14—3} w thick, without perceptible germ-pores ; 
paraphyses capitate, with a thin pedicel, occasionally clavate, 
thickened (up to 10 yz) above, hyaline, 35—80 x 15—24 u. 
Fig. 257. M. Larici-epitea. Fig. 258. Mf. Iarici-epitea. 
Cxeoma on Larch leaf, x2 Uredospores and _ para- 
(one of Plowright’s cultures physes, on S. viminalis. 
from S. cinerea). 
Teleutospores. Sori amphigenous, covered by the epidermis, 
at length dark-brown, sometimes tinged round with greyish- 
blue or violet, }—1 mm. diam., densely clustered or confluent ; 
spores prismatic or subclavate, rounded at both ends, occasion- 
ally narrowed above, 20—50 x 7—14 ; epispore clear-brown, 
uniformly thin, without an evident germ-pore. 
Cxeomata on Larix europaea; uredo- and teleutospores on 
many species of Saha The teleutospores in October and 
November. (Figs. 257, 258.) 
This species is one of the most complex of all the Melampsoracez ; it 
has been divided into about eight biological races, all of which have their 
ceoma on Larch, while the other spore-forms are specialised to certain 
species of Willow. It is recorded on the following British Salices for 
other countries, but it is not possible as yet to say on which of these it is 
found in this country: S. aurita, Caprea, cinerea, fragilis, Smithiana, 
viminalis for the typical form ; nigricans for the form M. Lariei-nigricantis 
Schneider ; purpurea for the form M. Larici-purpureae Schneider ; and 
reticulata for M. Larici-reticulatae Schneider. Morphological differences 
between these forms are not discoverable. 
The teleutospores germinate in the spring following after their forma- 
tion. The teleuto-sori are formed under the epidermis, and appear to 
start usually just below a stoma; they often occupy entire areas bounded 
by the veins. This description is taken mainly from Fischer. The 
teleutospores are distinguished from those of M. Larici-Caprearum by the 
total want of thickening at the apex. Plowright produced the ceoma on 
Larch from the teleutospores on Salix cinerea, May 24th, 1900. 
