23-10-2025 20:59
Patrice TANCHAUDBonsoir, est-ce que quelqu'un posséderait un com
24-10-2025 14:50
Riet van Oosten
Hello, Found by Laurens van der Linde, Oct. 2025
24-10-2025 03:11
Francois Guay
I found this fungus growing on decaying conifer wo
20-10-2025 09:36
Nicolas VAN VOOREN
Hello.I'm searching for the following article:Bene
21-10-2025 23:13
F. JAVIER BALDA JAUREGUIHello to everyone.Did you think it could, be a pyx
22-10-2025 14:45
Lukas VerboomDear all,I collected this in the Netherlands, on t
22-10-2025 11:13
Jean-Luc RangerBonjour, Petites boules plus ou moins sphériqu
21-10-2025 21:25
Philippe PELLICIERBonjour,J'ai récolté en septembre sur une litiè
Growing on Acer macrophyllum (bigleaf maple). Seen at the Yuba Watershed Fungus Fair.No asci observed. Many parathyses with tiny oil drops were seen, they measured 30 – 45 × 2 – 3 micrometers. Many clavate basidia-like things seen, however they never had sterigmata or spores inside. Those measured (28) 36 – 47 x (5) 7 – 8 micrometers.
That is probably Rhytisma punctatum. The US host-index lists it on Acer macrophyllum in California, Oregon and Washington. The "clavate, basidia-like things" are probably immature asci. These would be mature in the spring at about the time the new leaves are emerging on the tree.
Dave
Here are some more macro images... http://mushroomobserver.org/156379?q=1higi?
Edit: I understand that punctuate dots like this on Acer macrophyllum = R. punctatum, but there is another species with a somewhat similar appearence on other maples.
http://www.glfc.forestry.ca/VLF/ForumPresentations/hsiangtarspot_08e.pdf