Accès membres

Mot de passe perdu? S'inscrire

24-03-2026 21:37

Helminthosphaeria
Elisabeth Stöckli

Bonsoir,Sur bois (tronc) très pourri de conifère

25-03-2026 10:35

Encoelia impudicella?
Hulda Caroline Holte

Hello,I collected this species growing on a dead b

26-03-2026 15:31

Hymenoscyphus ombrophiliformis?
Ãke Widgren Åke Widgren

Hello,I found this one in October last year, on r

26-03-2026 12:50

Pseudombrophila
David Chapados David Chapados

Hi,I'm having a hard time figuring which Pseudombr

26-03-2026 11:17

asco in Ulmus
Vasileios Kaounas Vasileios Kaounas

Found 11-03-26, in leaf of Ulmus sp. Diameter 2-4

25-03-2026 22:23

Orbilia with resin deposits
Marc Detollenaere Marc Detollenaere

Dear Forum,On a debarked stem of Tilia, we found s

24-03-2026 15:44

Leptodontidium cf. trabinellum
Åge Oterhals

I hope someone can confirm the name of this collec

25-03-2026 20:53

Didymopsis helvellae on Helvella?
François Bartholomeeusen

Dear forum members,On 23 March 2026, I found sever

23-03-2026 20:16

Coprotus 210226 315
Miguel Ãngel Ribes Miguel Ángel Ribes

Good eveningI'm unable to identify this Coprotus o

25-03-2026 15:06

Hyaloscypha albohyalina à confirmer
Bernard CLESSE Bernard CLESSE

Bonjour à toutes et tous,Pourriez-vous me confirm

« < 1 2 3 4 5 > »
Black dots on maple leaf
Alan Rockefeller, 31-12-2013 11:00
Alan RockefellerGrowing 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.

  • message #26494
Jacky Launoy, 31-12-2013 12:58
Re : Black dots on maple leaf
Rhytisma acerinum (Pers.:Fr.) Fr.
David Malloch, 31-12-2013 15:34
David Malloch
Re : Black dots on maple leaf
Hi Alan..
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
Byrain, 31-12-2013 16:47
Re : Black dots on maple leaf
Alan, I found that leaf and posted it on MO as Rhytisma punctatum.  I have the other two leaves from that collection also.  I scoped them too and also saw no mature asci.

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