Oddworld1000

Differentiating between d. Intermedia and d. Anglica

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Hi all. How can I tell the difference between d. Intermedia and d. Anglica in the wild. I’ve read that intermedia has a round or oval cross section of the leaf stem and anglica has a flat cross section but I’ve never seen anglica before so not sure if this is true. Looking at images on the net of anglica they appear to have a round cross section too.

There is a really nice marsh area close by (30 miles or so away) that I’ve visited before and it has loads of intermedia and rotundifolia growing. I’ve read a scientific report that claims to have found anglica there too but that is the only source I’ve found with this claim. I’ll be visiting there again in the summer and would nice to know if I do happen to come across an anglica by chance.

thank you.

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The leaves of Drosera anglica are generally substantially longer than those of Drosera intermedia. That said, if they're all growing in the same area, there are bound to be lots of hybrids, too (and even Drosera anglica itself is thought to originate from a hybrid between Drosera rotundifolia and Drosera linearis - which is itself yet another lookalike). Here's an image to show the difference:

ebo01821.jpg

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19 hours ago, Oddworld1000 said:
Hi all. How can I tell the difference between d. Intermedia and d. Anglica in the wild. I’ve read that intermedia has a round or oval cross section of the leaf stem and anglica has a flat cross section but I’ve never seen anglica before so not sure if this is true. Looking at images on the net of anglica they appear to have a round cross section too.
There is a really nice marsh area close by (30 miles or so away) that I’ve visited before and it has loads of intermedia and rotundifolia growing. I’ve read a scientific report that claims to have found anglica there too but that is the only source I’ve found with this claim. I’ll be visiting there again in the summer and would nice to know if I do happen to come across an anglica by chance.
thank you.

Hi Oddworld,
It's dead easy to tell the difference between the two. Intermedia is smaller, the leaves are shorter, and the tapered part at the petiole takes up a large part of the leaf. The leaf of anglica is bigger and longer, and the tapered part at the petiole takes up a small percentage of the while leaf.

In addition to that, you usually only find intermedia growing on peat at the water's surface.

Sent from my PLK-L01 using Tapatalk
 

Edited by Karsty

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The leaves of Drosera anglica are generally substantially longer than those of Drosera intermedia. That said, if they're all growing in the same area, there are bound to be lots of hybrids, too (and even Drosera anglica itself is thought to originate from a hybrid between Drosera rotundifolia and Drosera linearis - which is itself yet another lookalike). Here's an image to show the difference:
ebo01821.jpg
Hey Carambola [emoji4]

Those paintings are very nice, trouble is, they aren't accurate. A lot of old botanical illustrations are like that.


Sent from my PLK-L01 using Tapatalk

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I'd agree on the drawing of the rotundifolia, which is borderline offensive, but the other two look reasonably accurate to me. In fact, I just noticed they illustrate another clear difference between the two: anglica's leaves always grow upright, whereas intermedia's leaves first grow outward in a rosette, and only then go up.

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Thank you for your comments Karsty and Carambola.

The painting are a really nice illustration of the UK sundews.

The problem with trying to differentiate by size is that it may be a large mature intermedia or small young anglica. Looks like the seed or pollen may be the best way to tell the difference (whatever the image to the side of each plant is), not very useful for field ID though. 

I’ll pay closer closer attention to the leaf growth and habitat next time I visit. There were sundews everywhere, even on the edges of the tyre tracks along the forestry path, which was quite a way from the water. Can’t remember if they were flat or upright growing dews though, it was five years ago.

I’ll take my macro lense on my next trip and post some pics. Hopefully the u. Vulgaris will be in flower again.

Quote

 

 

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Do you know what Oddworld? I bet you just need to see a certain number of each, and then you will be able to recognise them more easily. You know, you get to recognise "the look" of different plants.

Apparently D. anglica has been spotted in western parts of the New Forest.

If it was me, I'd be tempted to grow both of them myself to help me ID them in the wild.

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It is easy to tell Drosera intermedia appart from other temperate species and hybrids as its scapes are emerging laterally from the rosette of leaves, while it is emerging from the center of the rosette in other taxa.

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I think you are right Karsty. I’m quite good a spotting ground orchids which are not in flower (finding, not necessarily ID’ing), they just stand out from everything around them. I will eventually get one of each dew to compare but I recently brought a mixed batch of 250 drosera seeds to boost my collection. Currently have only 1 d. Adelae which I got bare root in January, the crown turned to mush but it’s sprouting from the roots. Need to find out what seeds grow and sort out space and water before I buy anymore plants. Might have intermedia or anglica in the mix already. Might be harassing everyone for help with plant IDs in a few months.

We have some customers in the new forest so I’ll take my wellies with me next time I’m down there and go exploring on the way back. 

Thanks for the info to kisscool, I’ll try time my field trip for when they are flowering and check where the scapes emerge.

 

 

 

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

I grew intermedia in my bog garden a few times, but they always disappeared. The same happened with rotundifolia. It seemed that they got overwhelmed with Sphagnum and I was not quick enough to save them. It's weird, because rotundifolia usually grows on Sphagnum in habitat. Not sure what happened to the intermedia, as I grew them on the water surface on wet peat where there was no Sphagnum.

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17 hours ago, Karsty said:



I grew intermedia in my bog garden a few times, but they always disappeared. The same happened with rotundifolia. It seemed that they got overwhelmed with Sphagnum and I was not quick enough to save them. It's weird, because rotundifolia usually grows on Sphagnum in habitat. Not sure what happened to the intermedia, as I grew them on the water surface on wet peat where there was no Sphagnum.

Hi Karsty! Did they disappear in winter? Is possible that the hibernacula had rotten? In my experience I’ve lost d. Rotundifolia only in winter due to the too high humidity

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Hi Argo :biggrin:

It was as though they gradually disappeared. It could have been in the winter. But they vanished within a couple of years of planting. I wasn't strictly monitoring them at the time. With all this talk, I'm contemplating trying them again, and anglica, but giving them more attention.

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This time I don’t say You to wait if the boarn again this spring :-D :-D good luck!!!;-)

Edited by Argo88

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On 3/9/2018 at 10:14 AM, Argo88 said:

This time I don’t say You to wait if the boarn again this spring :-D :-D good luck!!!;-)



 

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