Crocus October 2007

[mark smyth]

refund! I wasnt offered one last year only "I'll contact my supplier"

[hadacekf]

Tony and Zhirair,
Thanks, for the comprehensive help. I observed these unusual leaves only with two Crocuses. However I had always Crocuses with such unusual leaves in the past years and sometimes I removed this Crocus. Fortunately it gives now the forum.

[Casalima]

Crocus tournefortii, in the Alpine House at Kew, yesterday.

Chloë

[David Shaw]

This is a  picture of our well chewed Crocus cartwrightianus. It is sharing a sand plunge with 15 or more autumn flowering crocus and this is the only one that has been chewed; every flower has suffered the same fate, some having been comletely eaten away. I have searched for slugs and snails etc but found nothing. Any idea what this selective beastie might be?

[Maggi Young]

David, I see some of the leaves in the background look a bit crinkled ( see Franz' post earlier in this thread on this subject)..... are you surethe flowers HAVE been chewed... might they not have been caught up in the cataphylls as the  shoots were emerging and have become torn as they opened?

If they have been truly munched, then I suspect a sparrow.

[David Shaw]

Maggie, I would say no and no. The flowers strted off well formed and have slowly been attacked. The one at the top of the picture, left of centre, has nothing left at all. Sparrows, I would not have thought would be so selective and the openings on the greenhouse are mostly screened. Anyway, that is why we love CATS Thanks for the effort.

[Maggi Young]

Oh dear, that's not so good then is it? I see the one at the back left now, well chewed.  It's out there with a head torch and a glass of gin for you for the next couple of nights, till you catch the culprit.
Cheers!
 M

[tonyg]

David - I would suspect cutworm.  They lurk unseen in the topdressing or just below the surface of the compost - and not necessarily in the pot which is attacked.  Here is a pic of one at 'rest'.  Not sure if they are usually nocturnal but suspect they would be safer if they were!

[tonyg]

And now to pick up an even more distressing thread.  Virus.  Notably the mosaic virus that Zhirair has shared his knowledge of.  Here are some images (taken here today) of plants carrying a virus.  The leaf image has been 'altered' slightly to highlight the blotchy nature of the leaves but it is visible to the naked eye in real life.  I still believe that this also reveals itself in the flowers, see the other images below.  The Crocus longiflorus are the flowers above the virused leaves - not quite perfect.  The Crocus serotinus has noticeably streaky flowers. 
I am rigorously checking all my crocuses (and other bulbs) as the flowers/leaves appear.  ANY that are suspect are being removed to a quarantine area away from the rest of the collection.  If seed is produced I will collect and sow it then the plants will be burnt.  I want to collect and sow seed from plants known to be virused to test the theory that seed is 'clean'.

[tonyg]

It is not all doom and gloom!!
Although flowering this autumn has been a bit subdued there are some nice things to share.  I am sure that the relatively poor flowering is largely due to the very hot weather in late March and April which pushed the plants into early dormancy just at the time when new buds were being formed in the developing corms.

Crocus niveus - 2 forms, one tall the other short.

Crocus medius - ex Martin Baxendale

Crocus unknown taxa - perhaps a white C thomasii but not the C cartwrightianus that it resembles - the style divides in the wrong place!

Crocus biflorus melanthreus - 2 forms in same pot.  Note the black anthers.

[tonyg]

One last post - I'm home alone tonight, won't have this much time again for a while

Zhirair has made it clear he likes his crocus large flowered.  How does this compare in the contest where big is beautiful ( for Maggi 

Crocus speciosus in the garden with Colchicum Rosy Dawn.  This is the biggest crocus flower that I have ever seen!

[annew]

  I thought C biflorus was a spring flowerer?

[Armin]

And now to pick up an even more distressing thread.  Virus.  Notably the mosaic virus that Zhirair has shared his knowledge of.  Here are some images (taken here today) of plants carrying a virus.  The leaf image has been 'altered' slightly to highlight the blotchy nature of the leaves but it is visible to the naked eye in real life.  I still believe that this also reveals itself in the flowers, see the other images below.  The Crocus longiflorus are the flowers above the virused leaves - not quite perfect.  The Crocus serotinus has noticeably streaky flowers. 
I am rigorously checking all my crocuses (and other bulbs) as the flowers/leaves appear.  ANY that are suspect are being removed to a quarantine area away from the rest of the collection.  If seed is produced I will collect and sow it then the plants will be burnt.  I want to collect and sow seed from plants known to be virused to test the theory that seed is 'clean'.

Tony,
thanks for posting a close picture of the virused leaf and the flower images. I'll remember it and keep an closer eye on it. The flower of C. serotinus is obvious unnormal while the C.longiflorus flowers looks still fine to me. Hhm difficult... I hope you can prove viruses are not spread by seed. Good luck!

[tonyg]

Aah - it is except for this one subspecies.

Mind you, take nothing for granted, Steve Keeble has found a Spring flowering form of Crocus biflorus subspecies melantherus .... complete with black anthers .... which maintains the flowering time in cultivation.  (Raised from wild seed - no wild plants were hurt in this exercise

[Armin]

Tony,

I learned from your crocus pages C. biflorus wattiorum is also late autuum flowering...
There are two autuum biflorus subspecies - right?

Just want to add. the C. biflorus melantherus is a very beautiful subspecies.