382 HEMILEIA 
On leaves of Cattleya Dowiana Batem., imported from 
Costa Rica, 1899. (Fig. 285.) 
Only a small patch of Rust was present on the leaf when the plant 
was received from Costa Rica, but this continued to increase in size and 
the falling spores infected other leaves. The uredospores germinated 
readily, and young Cattleya leaves, inoculated on the under surface, 
produced mature uredospores in thirteen days. No success attended the 
efforts to infect other orchids, not belonging to the genus Cattleya. 
This description is founded on that given in the Kew Bulletin; on 
referring to the Gardener's Chronicle (/.c.) it will be seen that the 
particulars there given differ in several respects. The specimen is in the 
Kew Herbarium. This fungus and the others of the same genus might 
easily become dangerous parasites in orchid houses, if allowed to spread ; 
though it seems probable, on the slender evidence at present known, that 
each is confined, like most other Rusts, to a single genus, if not species. 
Hemileia Phaji Sydow. 
Oredo Phojr Raciborski, Parasit. Alg. und Pilz. 1900, ii. 32. 
U. Lynch Adams, Irish Naturalist, 1911, xx. 68. 
Hemileia Phaji Sydow, Monogy. iii. (ined.). Grove, Journ. Bot. 1913, 
p. 44. 
Fig. 286. H. Phaji. a, epidermis, showing fascicle of uredospores emerging 
from a stoma, x 180; b, the same in section; c, uredospores, x 600; d, a 
portion of a leaf, with uredo-sori, in Herb. Kew, x}. 
Uredospores. Sori hypophyllous, densely scattered, round, 
distinct, formed of little dense fascicles of hyphe (20—25) 
which issue through a stoma; pedicels divergent, clavate up- 
wards, each surmounted by a spore; spores subglobose or rarely 
