ON MALVACEE 207. 
On many species of Malvacee (of the subfamily Malveze), 
especially on Malva moschata, M. silves- 
tris and Althaea rosea. Very common. . 
May—October (also in April and Novem- 
ber). (Fig. 154.) 
This is.one of the most noticeable of the | 
Uredinales. It is truly plurivorous ; so far 
from being confined to a species, it is not even 
confined to a genus. In botanic gardens, where ; 
species of the family Malvacez are grown, side 
by side, in the same plot, the disease can be 
seen to spread to plants of all the allied genera 
—NMalva, Lavatera, Althaea, Kitaibelia, Malope, 
Abutilon, Sida, Sidalecea, Anoda, Malvastrum, ; 
etc., have been recorded. A list containing ; 
many (nearly forty) species of these genera is 
given by Sydow, to which more are added by 
Fischer, McAlpine, and Dandeno. Onallthese _ .- 
it appears to be identical ; artificial infections ny Las ares Yaa 
a eis eleutospores and meso- 
have proved that it can be transferred from spore. 
Malva to Althaea, and vice-versd. 
It was first made known in 1852 by Montagne from a specimen found 
in Chili. It was observed in Australia in 1857 (McAlpine). In Europe it 
appeared in 1869, in South Africa in 1875, and it is now spread all 
over the world. It is believed that Chili was its native home; the 
rapidity of its distribution to other countries has few or no parallels among 
plant diseases. 
It has been proved by many experimenters that it produces only the 
one kind of spore, which is capable of germinating at once when mature, 
though some can hibernate. It is a disputed point whether the mycelium 
can pass the winter in the plant or in the seed: the balance of evidence 
goes to show that fresh infections arise each year by the germination 
of over-wintered teleutospores, which can be found on all green parts, even 
on the fruits. See p. 48. 
79. Puccinia Pruni-spinose Pers. 
Heidium punctatum Pers. in Uster. Annal. Botanik, xx. 135. Plowr. 
Ured. p. 268. 
4, quadrifidum DC. Flor. fr. vi. 90. Cooke, Handb. p. 586; Micr. 
‘Fung. p. 194. 
Puccinia Pruni-spinosae Pers. Syn. p. 226 (1801). Sydow, Monogr. i. 
484, Fischer, Ured. Schweiz, pp. 157, 547, ff. 21, 122, 340. 
McAlpine, Rusts of Australia, p. 171, f. 83-—6 and pl. D, f. 19—20. 
