Biology Reference
In-Depth Information
sunflower, zinnia, and others. The same sort of
cottony mold is formed on flower stems as on
vegetables, but here the sclerotia are usually
inside the pith and so are rather long and thin.
You can feel them by running thumb and finger
along the stem; sometimes the cottony mycelium,
or cracks in the stem, or one or two external
sclerotia indicate their presence. They are com-
mon in peony stems. When sclerotia are formed
in flowers, the shape corresponds to floral parts.
Sunflowers have large compound sclerotia.
Control
Cut out and destroy affected parts, try-
ing to keep sclerotia from falling out onto soil.
Dusting with sulfur sometimes checks rapid
spread of mycelium.
Sclerotinia trifoliorum
Root Rot
,
Stem Rot
of
cocklebur and alfalfa.
Steccherinum
Basidiomycetes, Aphyllophorales
This genus has been separated off from
Hydnum
.
The pileus is sessile or substipitate and laterally
attached, on a woody substratum; spines are
terete or flattened; cystidia present;
spores
white, smooth.
Climacoden septentrionalis (formerly
Steccherinum septentrionale
Syn.
Hydnum
septentrionale
)
White Spongy Rot
of heartwood
of living maples, beech, hickory, and other hard-
woods. A zone of brown discolored wood is
around the white rot area, and there are fine
black zone lines. The fruiting bodies are large,
soft, soggy, creamy white, in very large, bracket-
shaped clusters on trunks.
Hericium obietis (formerly
Steccherinum
abietis
Syn.
Hydnum abietis
).
Brown Pocket
Rot
of heartwood of living firs and western hem-
lock in Pacific Northwest. Elongated pockets,
empty or with white fibers, are separated by firm
reddish brown wood. Sporophores are like coral,
white to cream, up to 10 or 12 inches high and
wide, usually on dead trees, sometimes in wounds
of living trees.
Steccherinum abietis Syn.
Hydnum abietis
(see
Sclerotium
Blights
.
Sclerotium cepivorum
White Rot
of onion,
shallot and garlic. Affected plants die from
a rotting at the neck, at which point there is
a surface crust of small black sclerotia and
a thin weft of white mycelium. The sclerotia are
smaller and rounder than those of
Botrytis
. Roots
are often rotted off, and sometimes spots in a field
covering several square yards are infested.
Sclerotium rolfsii (including
Sclerotium
delphinii
).
Crown Rot
of delphinium, iris, ajuga,
aconite, quinoa, sainfoin, kiwi, and many other
ornamentals and vegetables,
Root Rot
and
Wilt
of
peanut,
Wet Scale Rot
of narcissus,
Southern
Blight
. For a full discussion see
▶
Hericium obietis
).
Brown Pocket Rot
of
heartwood of living firs and western hemlock in
Pacific Northwest.
Steccherinum septentrionale
▶
Syn. Hydnum
septentrionale (see
Climacoden
septentrionalis
)
White Spongy Rot
of heartwood
of living maples, beech, hickory, and other
hardwoods.
▶
Pellicularia
▶
rolfsii
under Blights.
Seaverinia
Stereum
Ascomycetes, Helotiales
Basidiomycetes, Aphyllophorales
Apothecia shallow, cup-to disc-shaped; a stroma
formed but no definite
Effused-reflexed to stipitate; spore-bearing sur-
face smooth, pale brown, upper surface with
a velvety coating of hairs, formed in several dis-
tinct layers; gloeocystidia and cystidia present or
lacking; spores smooth, colorless.
sclerotia;
conidia
botryose.
Seaverinia geranii (Syn.
Sclerotinia geranii
).
Rhizome Rot
on geranium.
