This Æcidium, which is common in this country upon
Rumex hydrolapathum
, Huds,
obtusifolius
, Linn.,
crispus
, Linn., and
conglomeratus
, Murray, was regarded by Fuckel and Cooke as being a condition of
Uromyces rumicis
(Schum .), is now stated by Winter in his last work to be a condition of
Puccinia magnusiana
. During the present year I have conducted a series of cultures, in which the life history of this fungus has been carefully, if not laboriously, worked out, from which it appears that
Æcidium rumicis
bears the same relationship to
Puccinia phragmitis
(Schum.) (=
P. arundinacea
, D. C.) as
Æcidium berberidis
, Gmel., bears to
Puccinia graminis
, Perss.
History of the Subject
.—Winter, in 1875, showed that those botanists who had associated this Æcidium with the
Uromyces rumicis
, simply because these two fungi occurred upon the same host plant, were wrong, and that the fungus in question was the æcidiospore of
Puccinia phragmitis
. Stahl, in 1876, repeated Winter’s experiment, and confirmed it. Now it happens that there are two
Pucciniœ
common upon
Phragmitis communis
, the (Schum.), and
P. magnusiana
, Körn. In March, 1877, Schröter placed the spores of both these
Pucciniœ
upon
Rumex hydrolapathum
(the species Winter originally experimented with), and found that the Æcidium was only produced from
P. magnusiana
. Winter, in the “Kryptogamen Flora,” now in course of publication, accepts Schröter’s statement, and gives as the æcidiospores of
Puccinia magnusiana
, not only the Æcidium on
Rumex hydrolapathum
, but also on
R. cripus, conglomeratus
,
obtusifolius
, and
acetosa
, and adds a note to the effect that the Æcidium upon
Rheum officinale
has probably the same life history.
Bacterial disease of Pisum Sativum
