Biology Reference
In-Depth Information
Sclerotinia
(Syn.
Whetzelinia
)
Rhabdospora
sclerotiorum
Basal Canker
on Euonymus.
Stem Canker
and
Wilt
on sage.
Deuteromycetes, Coelomycetes
Septobasidium
Pycnidia separate, not produced in spots,
erumpent, ostiolate; conidiophores short, simple
conidia hyaline, filiform to needle-shaped, with
several cells; parasitic or saprophytic.
Rhabdospora rubi (see
Basidiomycetes, Septobasidiales
Septocyta ruberum
).
Cane Spot
,
Canker
of raspberry.
Septocyta ruberum (formerly
Rhabdospora
rubi
).
Cane Spot
,
Canker
of raspberry.
All species are on living plants in association
with scale insects; the combination causes dam-
age to trees. Fungus body variable, usually resu-
pinate, dry, crustaceous or spongy, in most
species composed of subiculum growing over
bark; a middle region of upright slender or thick
pillars of hyphae supports the top layer, in which
hymenium is formed. Basidium transversely sep-
tate into two, three, or four cells, rarely one-
celled; basidiospores elliptical, colorless, divided
into two to many cells soon after formation, bud-
ding with numerous sporidia if kept moist. Some
species with conidia.
The fungus lives by parasitizing scales,
obtaining food via haustoria. The insects pierce
the bark to the cambium, sometimes killing
young trees. The fungus kills a few scales but
protects many more in its enveloping felty or
leathery covering, a symbiotic relationship.
Spores are spread by scale crawlers and by
birds. Most felt fungi are found in the South,
abundant on neglected fruit, nut, or ornamental
trees, rare on those well kept.
Septobasidium burtii
Felt Fungus
on southern
hackberry, beech, pear, apple, and peach. This is
a perennial growth, with a new ring added to the
patch each summer. Probasidia are formed during
the winter, and four-celled basidia in spring.
Septobasidium castaneum
Felt Fungus
abun-
dant on willow and water oaks, and holly; may
injure azaleas. The surface is smooth, shiny,
chocolate brown to nearly black.
Septobasidium curtisii
Felt Fungus
, wide-
spread on many trees in the Southeast, commonly
on sour gum (tupelo) and American ash, also on
hickory, hawthorn, Japanese quince, and others.
The felt, purple-black throughout, is mounded
over the insects.
▶
Scleroderris
Ascomycetes, Helotiales
Apothecia black, opening with lobes, crowded
together or with a stroma, short-stalked; spores
hyaline, elongate, with several cells.
Ascocalyx
abietina (formerly
Scleroderris
lagerbergii
Gremmeniella abietina
).
Canker
¼
on pine.
Grovesiella abieticola (formerly
Scleroderris
abieticola
).
Canker
of balsam fir, on Pacific
Coast. An annual canker, starting in autumn and
ceasing when cambium is active in spring, is
formed on twigs, branches, and trunks of sap-
lings. Only twigs and small branches are girdled,
and if this does not happen before spring, the
wound heals over. Small black apothecia with
short stalks appear on dead bark. Ascospore
infection is through uninjured bark or leaf scars.
Scleroderris
Grovesiella
abieticola
).
Canker
of balsam fir, on Pacific
Coast.
Scleroderris
abieticola (see
▶
lagerbergii Syn.
Gremmeniella
abietina
(see
Ascocalyx abietina
).
Canker
on
▶
pine.
Scleroderris lateritium
Canker
on pine.
Sclerotinia
▶
Blights
.
