Can someone identify the type of St. Johns Wort please?

[birderbryan]

This specimen was at Warton Crag, Nr. Silverdale, Lancashire yesterday July 3rd 2009. I was wondering if someone could actually tell me what sort of St. Johns it is. The crag is limestone. Thank you.
Bryan

[Adam Cheeseman]

Perforate by the looks of it.

Cheers,

Adam

[KeenTeen17]

Originally Posted by Adam Cheeseman

Perforate by the looks of it.

Cheers,

Adam

Good to see another Silverdale plant hunter. Warton Crag is great for plants Anyway Perforate St Johns Wort is correct

[birderbryan]

Thanks Adam, and Lancashire Nature, much appreciated.
Bryan

[earthdragon64]

Originally Posted by Adam Cheeseman

Perforate by the looks of it.

Cheers,

Adam

That's interesting, I have a couple of types of St Johns Wort growing near me which I'm finding a bit tricky to sort out. Can you tell me please which features are the crucial identifiers for the plant in the first post?

[Adam Cheeseman]

Personally I go by jizz of the plant tbh and familiarity with the plant.

ID features at this range in the pic would be difficult to pick up, with the exception of the general structure of the plant.

Got any pics of your plants you can post.

cheers,

Adam

[metalfish]

i.d'ing Perforate St John's wort is easy...pull a leaf off, hold it to look through it..if you can see pin-prick holes then it is Perforate (hence the name!)

[earthdragon64]

Originally Posted by Adam Cheeseman

Personally I go by jizz of the plant tbh and familiarity with the plant.

ID features at this range in the pic would be difficult to pick up, with the exception of the general structure of the plant.

Got any pics of your plants you can post.

cheers,

Adam

Apart from Slender, Trailing and Marsh, I'm still trying to get my head round the Hypericum group, so here goes.

The first two pictures are different views of the same plant at Loch Insh near Kincraig;





The third is a different plant on the Isle of Eigg,



The fourth was taken at Findhorn on the Moray coast, I had to hold it as it was a bit of a windy day,



Finally, this one was taken just outside Craigellachie NNR to the south of Aviemore,



Any help will be gratefully received.

[KeenTeen17]

1 &2) Imperforate St Johns wort

3) Perforate St Johns Wort

4) hard to tell without foliage

5) Imperforate St Johns Wort

[AlanS]

The first photograph, from Warton Crag, is almost certainly Hypericum x desetangsii, the hybrid of Perforate and Imperforate St. John's-Worts.

I cannot make out the sepal characters but they are evidently too finely pointed for Imperforate, while what we can see of the glands on the petals and the stem characters would appear to rule out Perforate.

The hybrid is locally common, variable and partly fertile, indeed probably more common than true Hypericum perforatum in the north.

The main snag is that I know someone doing research on the group and promising a substantially extended taxonomic treatment of this complex at some time in the future.



As for the set of photographs posted by Earthdragon64:


Loch Insh

Yes, Imperforate: Hypericum maculatum subsp. obtusiusculum

Eigg

A bit of an oops here, the plant is actually Square-stemmed St. John's-wort, Hypericum tetrapterum.

Findhorn

True Perforate St. John's-wort, Hypericum perforatum. Nice to see genuine Scottish material, but Findhorn is a bit special.

Craigellachie

Yes, Imperforate: Hypericum maculatum subsp. obtusiusculum


Alan