Observation 219932: Gymnosporangium clavipes Cooke & Peck
When: 2015-10-02
No herbarium specimen
0 Sequences

Proposed Names

28% (1)
Recognized by sight

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Eye3 = Observer’s choice
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My bad – it’ a Crataegus
By: Andrew Khitsun (Andrew)
2015-10-20 20:15:10 PDT (-0700)

I looked at several studies, and it seems to me that there are three species most commonly circulated in most forestry and landscaping bulletins, of which only quince-cedar rust has these protruding aecia on fruit. The other species produce aecia on leaves, and/or yellow circles with black dots on leaves. I am yet to figure out the difference between them in their form on Juniperus. The most detailed study I could find is here:
Also, I like this one:
There is motherload of others, including the one you cite, except they don’t have good illustrations. Gymnosporangium clavariiforme seems to be similar to G.clavipes but has a common name European Hawthorne Rust and appears on most European sites and also on few Western sites. It may or may not be present in our area.

I think this is on Crataegus (Hawthorn)
By: Danny Newman (myxomop)
2015-10-20 19:57:26 PDT (-0700)

not Malus/Crabapple. the fruits are pretty small.

What is your reference for this species? As I try to ID my own hawthorn rust (Observation 220055), I’m seeing photographs of the same thing going under various names online, including G. clavipes, G. clavariiformis, G. juniperivirginianae and G. globosum. See: http://www.missouribotanicalgarden.org/...

It’s on a crabapple
By: Andrew Khitsun (Andrew)
2015-10-20 19:32:35 PDT (-0700)
is this on a rose hip?
By: Matt Welter (mattfungus)
2015-10-20 16:51:24 PDT (-0700)

Created: 2015-10-20 15:52:38 PDT (-0700)
Last modified: 2015-10-20 19:57:48 PDT (-0700)
Viewed: 33 times, last viewed: 2017-06-20 22:25:11 PDT (-0700)
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