Yashca's picture

Bramble Rust

Observed: 6th January 2012 By: YashcaYashca’s reputation in Fungi and LichensYashca’s reputation in Fungi and Lichens
Bramble Rust 1
Bramble Rust 2
Description:
Identifications

Caution: Do NOT use iSpot to identify fungi to eat!

Some fungi are very poisonous so a mistaken ID could have serious consequences.

  •  
    Likely ID
    Phragmidium sp.
    Confidence: It's likely to be this, but I can't be certain.
Species interactions

No interactions present.

Comments

Syrphus's picture

Certainly the right genus,

Certainly the right genus, and probably (on the basis of size of the spore-clumps) P. violaceum. P. bulbosum tends to have much smaller patches and less obvious red marks above.

M.

TRY

recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.

Yashca's picture

I heard that one of the

I heard that one of the species was more of a generalist, whereas the other was tied to one or only a few species, is this correct?

Syrphus's picture

P. violaceum is on R.

P. violaceum is on R. fruticosus agg., except for the Section Coryliifolia. P. bulbosum is on that Section and on R. caesius. There is an easy difference in the spores - see http://www.hbrg.org.uk/SotM/Phragmidium.html.

M.

TRY

recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.

AlanS's picture

Host distinction

The host distinction is highly but not completely reliable.

Yes, on section Corylifolii and R. caesius I, personally, have found only P. bulbosum. (Section Corylifolii is derived from hybrids of brambles with R. caesius, so the rust is showing itself to be a good taxonomist.)

And almost always, the rust on other brambles is P. violaceum.

However, several years ago, on a BMS meeting in central Ireland, I came across a hybrid bramble, between R. ulmifolius (the one truly sexual species in the true brambles and so able to hybridise with others) and R. vestitus. Clearly the poor bramble had not inherited rust resistance from either parent and it was infected with BOTH these Phragmidium species.

Alan