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Keep an eye on Ramsons

Posted: Tue May 26, 2015 8:00 pm
by Chris Yeates
There are some images of the aecia of the rust Puccinia sessilis on this website (correctly named I hasten to add) http://fungi.org.uk/viewtopic.php?f=9&t=9 . I would encourage others to check out all rusts on Ramsons they see as there may be a second and (just possibly) a third species involved.

Recognising P. sessilis aecia is relatively simple (when they are fully developed) as they have rather neat, usually circular, sori arranged with a distinctive "cup" around each element. That cup is made up of fungal material, of rather regular honeycomb-like pale cells - see accompanying images.
Pucses08.jpg
Pucses08a.jpg
The thing to look out for is sori which are much more irregular - "caeomoid" is the technical term - and what pale margin they may have is simply remnants of the plant's leaf cuticle. These sori belong to species of Melampsora. For a long time their presence in the UK was not accepted - perhaps they were genuinely absent, or (more likely) not recognised for what they were. Whereas P. sessilis alternates with the grass Phalaris arundinacea, if you find these caeomoid sori the likelihood is that you are in close proximity to Crack Willow trees. I am now convinced (having seen this in numerous spots around SW Yorkshire) that aecia of Melampsora allii-fragilis on Ramsons are not uncommon (they also seem to be attractive to molluscs and show "shot-holes" such as one rarely sees in P. sessilis).
Melall0b.jpg
There is just one other possibility, again long doubted as being British; similar (indistinguishable, except apparently by colour - a bit subjective for me) but alternating with poplars Melampsora allii-populina. This is not uncommon in its later uredinial and telial states on poplar leaves - the fungus does not need the Allium to complete its life-cycle; I have yet to see caeomoid aecia on Ramsons where there was no Crack Willow in the area, only poplars. If you do find this possibility, make a note of the site and revisit in late summer and look for the later stages (the uredinial stage can often be seen from metres away as the leaves, covered in it and with orange undersides, blow in the wind).

Also, now that the leaves are starting to go over look for damp rotting areas on the Ramsons leaves, especially near the tips. On the underside and with a handlens you will probably see the extremely common "mouldy" anamorph of the ascomycete Botryotinia globosa.

Good hunting
Chris

Re: Keep an eye on Ramsons

Posted: Tue May 26, 2015 9:57 pm
by Lancashire Lad
Hi Chris, - great to see you on the forum.

Superb photos as usual - and, for the first time, one of your excellent composite "plates" can be viewed at screen filling size!

Plenty of Ramsons about - although not much Crack Willow around here unfortunately! - But will still be keeping my eyes open for these.

Regards,
Mike.

Re: Keep an eye on Ramsons

Posted: Wed May 27, 2015 8:19 am
by Wood Wanderer
Welcome back Chris

Have missed your knowledge and of course the photos :D , so much to learn

Cheers

John

Re: Keep an eye on Ramsons

Posted: Wed May 27, 2015 11:09 am
by adampembs
Yes, glad to see you here, Chris. Love those macros :D

Re: Keep an eye on Ramsons

Posted: Thu May 28, 2015 9:24 am
by diggleken
Ramsons - mhhhh -this was on a Ramson stem yesterday at Ilkley - is it just choke? Grateful for any advice - I have it at home Chris.... :D
Just to add, there's an interesting Hoverfly - Portovenia maculata which is pretty much host specific on Ramsons - if you see one, it would be nice to have the record and I can let Roger Morris know......
Great to have you aboard from me too Chris. :shock:
Cheers
Ken

Re: Keep an eye on Ramsons

Posted: Thu May 28, 2015 12:32 pm
by Lancashire Lad
Hi Ken,

That's not Choke - in terms of Choke being Epichloƫ species.

Definitely a rust - so, being caeomoid, probably Melampsora allii-fragilis or Melampsora allii-populina.

You're gonna have to capitulate and dust the cobwebs off that microscope. :D :D :D :oops: :P ;)

Regards,
Mike.

Re: Keep an eye on Ramsons

Posted: Thu May 28, 2015 12:37 pm
by diggleken
Nice one Mike, thanks a lot - I knew it wasn't, but was at my wits end, so grabbed at straws.
You know when you go round in circles and end up nowhere.............I'm doing that with a whole raft of Lichens too from the seaside in Galloway!
Don't mention the microscope............ :idea: :oops: :cry: :roll: :roll:
Basically, its as Chris set out in the OP...... :shock: And Willows nearby, riverside - didn't see any Poplars........
Cheers
Ken