Many people are put off by the appearance of this fungus,
but I find it to be quite attractive, as well as fascinating. From a distance, the cedars appear to have
sprouted large orange blooms. I’ve heard
some ascribe Blob-like characteristics to these fungal masses, but I’ve never
seen one reach out and engulf passers-by.
The fungus reaches the cedar by way of airborne spores
produced by the fungus during the summer while in its apple host phase. Spores that successfully colonize the cedar
will form a small, hard nodule on the new cedar leaves. The nodule, called a gall, will grow in size
until it matures approximately 18 months later.
When spring rains and temperatures produce the proper conditions,
filaments called telia emerge from dimple-like structures on the gall’s
surface. Fully hydrated telia produce
the spores that will be released to colonize an apple tree. Spores produced by galls on the cedar cannot
establish themselves on cedar. They can
only colonize on apple, and spores from the apple can only colonize cedar. In order for the fungus to survive, both
apple and cedar must be present in the vicinity.
In most fungi, what we notice most are the reproductive
structures that must be exposed to successfully spread spores to the wind. This gall has been halved to reveal the body
of the fungus from which the spore producing telia emerge.
After the rain has passed, the telia begin to dry.
The telia will dry back to short stalks, but will swell
again when the next suitable rain occurs.
This process can recur several times during the spring season. So far, this has been an exceptional season
for the Apple Cedar Rust Galls. Judging
by the weather forecasts, the cedars may bloom several more times before the
season ends.
What a coincidence! I saw the same sort of fungus on another blog today too! (Debbie, at "It's All About Purple") Hers appeared to be the Juniper/Hawthorn version. In any case, it's a new one to me.
ReplyDeleteHi, Stew. The galls of the Hawthorn Cedar Rust, which we also have here, are generally smaller than those of the Apple Cedar Rust.
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