Speckled Tar Spot

(Rhytisma punctatum)

               
Occurrence

Common and widespread

 

No Image Available

Season

Spring to fall

Habitat/Hosts

mountain maple (Acer spicatum)

silver maple (Acer saccharinum)

 

 

 

 


Identification

This is a parasitic fungus infecting several species of maple (Acer). In Minnesota it infects only mountain maple and silver maple.

It appears as a more or less round, about ½ in diameter, yellowish-green spot with a dense cluster of numerous tiny, raised black specks.

In the fall a ring of green will be seen around areas infected by the fungus as the remainder of the leaf fades. The green areas remain photosynthetic.

 
Similar
Species

Tar Spot (Rhytisma acerinum) causes large solid black spots up to 1½ in diameter.


Distribution Distribution Map  

Sources: 4, 7, 26, 29, 30.


Comments

Two Scientific Names
The life cycle of this and most other fungi is pleomorphic. It has both an asexual reproductive phase (anamorph) and a sexual reproductive phase (telemorph). Each phase is often morphologically distinct. In the past, the International Code of Botanical Nomenclature allowed each phase to be assigned a different scientific name. It was incorrect to refer to the anamorph phase by the telemorph name, and vice versa. Some mycologists and molecular biologists consider this practice to be obsolete. Molecular phylogeny allows the accurate placement of a species in any part of their life cycle. On July 30, 2011, at the meeting of the XVIIIth International Botanical Congress in Melbourne, Australia, that practice ended. Prior to that meeting, the early, anamorphic phase of this fungi had been named Melasmia punctata. Both phases are now named Rhytisma acerinum.


Taxonomy

Division:

Ascomycota (ascomycetes)

  no rank:

saccharomyceta

 

Subdivision:

Pezizomycotina

 

No Rank:

leotiomyceta

 

No Rank:

sordariomyceta

 

Order:

Rhytismatales

 

Family:

Rhytismataceae

 
Synonyms

Melasmia punctata

Xyloma punctatum

 
Common
Names

Speckled Tar Spot

Tar Spot


 

 

 

 

 

 

       

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  Rhytisma punctatum - fungi kingdom
Nineli Lishina
 
   
 
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Published on Jan 25, 2015

Rhytisma punctatum - fungi kingdom

 
     

 

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