Biology Reference
In-Depth Information
Hyalopsora cheilanthis
Fir-Fern Rust
.0,Ion
balsam fir; II, III on rock brake, parsley fern,
and cliff brake.
Hyalopsora polypodii
Fir-Fern Rust
. General in
northern and western states on polypody fern and
woodsia.
erumpent, pulverulent; spores globoid or ellip-
soid, single on pedicels.
Species heteroecious when telia are on woody
plants; autoecious if telia are on herbaceous
plants (
Fig. 3
).
Malampsora abieti-capraearum
Fir-Willow
Rust
. 0, I on balsam, white, and alpine firs; II,
III on willows, widespread. Yellow spots on wil-
low leaves in early summer are followed by dark
pustules when the telial stage is produced. There
may be some defoliation.
Melampsora abietis-canadensis
Hemlock-
Poplar Rust
. 0, I on eastern hemlock; II, III on
various poplars. Cones have golden powdery
masses of spores over the surface; later shrivel,
turn black, and hang as mummies; no viable seed
produced. Uredia are golden powdery pustules on
undersurface of poplar leaves; in late summer
telia are formed in orange-yellow crusts that
change to black; in spring basidiospores reinfect
hemlock.
Melampsora arctica 0, I on saxifrage; II, III on
willow.
Melampsora farlowii
Needle And Cone Rust
of hemlock. 0, I unknown; III on hemlock.
Reddish slightly raised telia are on undersurface
of needles, shoots of the current year, and on
cones. Young shoots may be twisted and killed.
Injury may occur in nurseries and in ornamental
hedges.
Melampsora hypericorum (
Mesopsora
hypericorum
). On St. Johnswort, Montana.
Melampsora larici-populina
Rust
;0, I, on pine
and larch; II, III, on poplar.
Melampsora medusae
Douglas-Fir Needle
Rust
. 0, I on Douglas-fir, big-cone spruce; II, III
on native poplars. Pycnia are on upper surface of
current-year needles; aecia, of the caeoma type,
are orange-yellow on the undersurface. The rust
is often epidemic on young trees but with little
permanent ill effect.
Melampsora medusae
Larch Needle Rust
.0,I
on larch in northeastern states; II, III on native
and introduced poplars except in far South.
Melampsora medusae f. sp. deltoidae
Rust
;0,I
on Douglas fir, pine and larch; II, III, on poplar.
Melampsora occidentalis
Poplar Rust
.0,I
unknown; II, III on native poplars in the West.
Kuehneola
Puciniaceae. Teliospores two-to many-celled;
wall faintly colored or colorless.
Kuehneola malvicola
II, III on hibiscus and
malvaviscus.
Kuehneola uredinis
Yellow Rust
,
Cane Rust
.0,
I, II, III on blackberry, dewberry, and raspberry.
The disease appears to be increasingly prevalent,
especially on leaves, but there is a great difference
in varietal susceptibility. Eldorado, Foster, Jumbo,
Lawton blackberries are highly susceptible;
Nantichoke, Austin Thornless, Boysen Brainerd,
Burbank Thornless, Jersey Black are resistant.
European varieties are generally resistant.
Kunkelia
Pucciniaceae. Pycnia subcuticular; telia
subepidemal, caeomoid; teliospores catenulate,
one-celled.
Gymnoconia nitens (formerly
Kunkelia nitens
).
Short-Cycle Orange Rust
of blackberry. I, gen-
eral on blackberry but more common in the South
and West, also on dewberry and black, but not red
raspberry. This is a perennial rust, a systemic
disease with only the aecial stage present. Under-
side of leaves may be covered with quantities of
orange-yellow spores. Remove infected bushes.
Kunkelia nitens
Gymnoconia nitens
)
.
Short-Cycle Orange Rust
of blackberry.
(see
▶
Melampsora
Melampsoraceae. Telia more or less indefinite;
teliospores sessile, subcuticular or subepidermal,
forming crusts of a single layer; aecia when pre-
sent with
rudimentary
peridium;
uredia
