Accès membres

Mot de passe perdu? S'inscrire

23-03-2026 13:24

Paul Cannon

Could anyone provide me with a pdf of Auerswald'sÂ

20-10-2017 09:23

Garcia Susana

Este otro crecía en el mismo trocito de madera qu

21-03-2026 15:13

Lepista Zacarias

Hello everyone, Does any one know of any literatu

21-03-2026 22:59

Petr Soucek

Good evening, I would appreciate some advice on th

20-03-2026 12:53

Stefan Blaser

Hello everybody, In the field, from distance, my

20-03-2026 16:16

Edvin Johannesen Edvin Johannesen

These 0.5 mm diam. acervuli were breaking through

19-03-2026 19:34

Filip Fuljer Filip Fuljer

Hello everyone,a few days ago I collected this str

19-03-2026 18:25

William Slosse William Slosse

Good evening everyone, On 18/03/26 I found a few

17-03-2026 10:09

François Freléchoux François Freléchoux

Bonjour, Voici la description rapide d'un petit d

19-03-2026 15:58

Stefan Blaser

Hello everybody, I hope for some hints... Macro:

« < 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