Speckled Tar Spot

(Rhytisma punctatum)

Conservation Status

 

No Image Available

 
  IUCN Red List

not listed

 
  NatureServe

not listed

 
  Minnesota

not listed

 
           
           
           
 
Description
 
 

Speckled Tar Spot 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.  
     
 
Habitat and Hosts
 
 

Mountain maple and silver maple

 
     
 
Biology
 
 

Season

 
 

Spring to fall

 
     
 
Distribution
 
 

Distribution Map

 

Sources

4, 26, 29, 30, 77.

 
  6/8/2022      
         
 

Occurrence

 
 

Common and widespread

 
         
 
Taxonomy
 
  Kingdom Fungi (fungi)  
  Subkingdom Dikarya  
  Phylum Ascomycota (sac fungi)  
  Subphylum Pezizomycotina  
  Class Leotiomycetes  
 

Order

Rhytismatales  
 

Family

Rhytismataceae  
 

Genus

Rhytisma (tar spot fungi)  
       
 

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 punctatum.

 
       
 

Synonyms

 
 

Melasmia punctata

Xyloma punctatum

 
       
 

Common Names

 
 

Speckled Tar Spot

 

 

 

 

 

 

 

 
 
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Slideshows
 
Rhytisma punctatum - fungi kingdom
Nineli Lishina
   
 
About

Published on Jan 25, 2015

Rhytisma punctatum - fungi kingdom

 

 

slideshow

       
 
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