ON POLYGONACEX 223 
scattered singly : those of the Puccinia are in largish orbicular clusters 
and are rarely found singly ; if not clustered, they spread over the whole 
leaf. In Plowright’s herbarium are some leaves of Lychnis diurna, covered 
with uredo-sori, which he mistakenly assigned to P. Lychnidearum : there 
are no teleutospores of the latter, however, but a very few of P. Behenis 
were found in the same sori, See under P. Lychnidearum. The circinate 
arrangement of the sori, on paler spots, is very similar in both species. 
DistRiBuTIoN: Central and Western Europe. 
93. Puccinia Acetose Korn. 
Uredo Acetosae Schum. Plant. Sail. ii. 231. 
Puceinia Acetosae Korn. in Hedwig. 1876, p. 184. Plowr. in Trans. 
Brit. Myc. Soc. i. 57. Sace. Syll. vii. 688. Sydow, Monogr. 
i. 581. Fischer, Ured. Schweiz, p. 134, f. 101. 
Uredospores. Sori amphigenous, scattered, minute, roundish 
on the leaves, elongated on the 
petioles and stems, soon naked, 
ferruginous-brown; spores globose 
to obovate, sparsely aculeate, 
brownish, 24—30 x 20—28 yw, with 
two (rarely three) germ-pores. 
Teleutospores. Sori similar, but 
dark-brown; spores ellipsoid, ob- 
long, or subclavate, rounded at both ends or slightly attenuated 
below, not thickened at the apex, but furnished with a broad 
pore-cap, slightly constricted, delicately verruculose, chestnut- 
brown, 28—42 x 19—24 4; pedicels hyaline, slender, deciduous, 
as much as 35 wu long. , 
Fig. 171. P. Acetosae. 
Teleutospores and uredospore. 
On Rumex Acetosa. Malden, Yorkshire, July 16, 1894 
(A. W. Saunders), Ireland, co. Antrim (J. Adams), August, 
1909. Bewdley, Worcestershire, August, 1907, ete. (Fig. 171.) 
There is no doubt that this species is often mistaken for Uromyces 
Acetosae. In the absence of the two-celled teleutospores, which are rare, 
it could be distinguished mainly by its smaller sori, and more spiny 
uredospores (the spines are quite colourless). The teleutospores show the 
delicate warts more clearly on the upper cell ; in the Bewdley specimens 
they were perceptible only with great care. Magnus proved that this 
species can pass the winter by its uredospores. It may be heterccious. 
