Biology Reference
In-Depth Information
commonly attacked, balsam poplar less fre-
quently. This is usually a forest, rather than
a home garden, disease. Trees less than 30 years
old, growing on poor sites, are most susceptible.
Trunk cankers start as small, yellow to reddish
brown, slightly sunken areas, centering around
a wound, there grow together to form a canker
marked off by vertical cracks. The bark is mottled,
gray, with black patches where the blackened cor-
tex is exposed. Conidia appear in blisterlike stro-
mata on first-and second-year cankers, whereas
perithecia are formed on third-year cankers in
hard, black stromata covered with a white pruinose
coat. Ascospores are ejected in winter. Eliminate
infected trees when thinning stands.
Hendersonula
Deuteromycetes, Coelomycetes
Pycnidia black, stromata, one to several per stroma,
locules occurring at different levels in stroma;
conidophores long, flexuous; conidia often extruded
in cirrhi; at first one-celled, hyaline to yellowish,
later becoming three-to four-celled and dark.
Hendersonula toruloidea
Canker
on
Arbutus
menziesii
.
Hymenochaete
Basidiomycetes, Aphyllophorales
Kabatina
Pileus, fruiting structure, resupinate, of several
layers, with long, stiff, usually brown setae
(cystidia).
Hymenochaete agglutinans
Hymenochaete
Canker
on apple, birch, hazelnut, sweetgum, mis-
tletoe, and various young hardwoods. When an
infected dead stem comes in contact with a live
one, the mycelium forms a thin leathery fruiting
body around the living stem, holding it to the
dead stem. This resupinate structure is deep
brown in the center, with a yellow margin. The
stem is constricted at the point of encirclement,
and the sapling usually dies in 2 or 3 years. If the
dead stem is removed before girdling, a sunken
canker appears on one side, but this may be over-
grown with callus and disappear. Do not leave
severed stems in contact with living seedlings or
saplings in nursery stands.
Deuteromycetes, Coelomycetes
Kabatina juniperi
Blight
on eastern red cedar;
conidia produced in black acervuli on discolored
foliage.
Lachnellula
Ascomycetes, Helotiales
Apothecia mostly cup-shaped.
Lachnellula willkommii
(Syn.
Trichoscyphello
willkommii
).
Canker
of
European
larch
(
Dasyscypha
).
▶
Leptosphaeria
Diapleella coniothyrium (formerly
Leptosphaeria coniothyrium
).
Canker
on thorn-
less blackberry.
Leptosphaeria coniothyrium (see
Hypoxylon
Ascomycetes, Xylariales
Diapleella
coniothyrium
).
Canker
on thornless blackberry.
▶
Perithecia in a pulvinate stroma, often confluent
and crustose; ascospores with one cell, rarely
two, blackish brown; conidia in superficial layer
on surface of young stroma.
Hypoxylon mammatum
Hypoxylon Canker
of
poplar. Aspen and large-tooth aspen are most
Leucostoma
Leucostoma cincta
Canker
on apple.
