ON EPILOBIUM 199 
Pucecinia pulverulenta Grev. Fl. Edin. p. 432 (1824). Cooke, Handb. 
p. 507; Micr. Fung. p. 211, pl. 4, f. 78—9. Plowr. Ured. p. 151. 
P. Epilobit DC. ; Sace. Syll. vii. 608 p.p. 
P. Epilobii-tetragoni Wint. Pilze, p. 214 (1884). Sydow, Monogr. 
i. 424, Fischer, Ured. Schweiz, p. 152, f. 118. McAlpine, Rusts 
of Australia, p. 170, f. 79—81. 
Spermogones. Scattered among the ecidia, honey-coloured. 
Aicidiospores. Aicidia hypophyllous or, when very abundant, 
also epiphyllous, scattered rather closely over nearly the whole 
surface of the leaf, cup-shaped, with a white torn revolute 
margin; spores very delicately verruculose, orange, 16—26 yu. 
Uredospores. Sori hypophyllous, scattered or circinate, 
sometimes confluent, pulverulent, 
chestnut-brown; spores globose to 
ovoid, remotely echinulate, brown, ks 
20—28 x 1525 p, with two germ- 
pores. (0) ey, 
Teleutospores. Sori hypophyl- 
lous, often circinate, soon naked, _. 
Fig. 147. P. pulverulenta. Te- 
pulverulent, dark-brown > spores leutospores and uredospore. 
ellipsoid or ovoid, rounded at both 
ends, somewhat thickened above (up to 5) with a broad low 
cap-like addition, gently constricted, smooth, brownish, 24—35 
x 14—20 w; pedicels hyaline, slender, deciduous. 
On LEpilobium hirsutum, E. montanum, HE. tetragonum. 
fEcidia, May and June; teleutospores, June—November. 
Common. (Fig. 147.) 
The aecidium-forming mycelium appears (but perhaps falsely) to be 
perennial, for the same plants are attacked year after year. The acidia 
appear in May and cover leaf after leaf, as they are developed. The 
affected plants are easily recognisable by their much paler and yellowish 
colour. Soon the sori of uredo- and teleutospores begin to appear, at first 
on the same leaves, but afterwards on the later-formed leaves higher up 
the plant. In September and October the small last-formed leaves are 
thickly covered by the teleutospores ; it is probably from the germination 
of these in spring that the next attack proceeds. The mycelium of the 
uredo- and teleuto-sori is strictly localised. 
Plowright states (/.c.) that the ecidiospores sown on young seedlings of 
E. hirsutum gave rise to ecidiospores in seventeen days, but very possibly 
