Impatiens species of some sort? (1 Viewer)

An unusual plant has started growing in some areas where I have cleared out Himalayan Balsam. The flower looks very much like the flower of Himalayan balsam, but it is a dark orange. The stems again look similar to Himalayan balsam, but the leaves are smaller, especially not as long, and seem to be held in a less regular pattern than Himalayan balsam. The stems are hollow like balsam.

I tried to look up what it might be, and one possibility is yellow balsam (http://en.wikipedia.org/wiki/Impatiens_noli-tangere). The leaves and stems look to be a close match in the picture on Wikipedia. But the flowers on what I see are much darker than the yellow of the Wikipedia page, much more orange. Is it Impatiens Noli-tangere, or is there something else it could be?

Edit: Almost all pictures on google have the yellow flower, but this one picture (claimed to be I. noli-tangere) is the same colour as the plant I wish to ID. Does that mean that it is I noli-tangere? Or is this anomalous picture a misidentification of something else?

http://upload.wikimedia.org/wikipedia/commons/f/fc/Impatiens-noli-tangere-flower.jpg

Sounds like Orange Balsam or Jewelweed, Impatiens capensis.

Having looked at photos, that's it. I've read up on it, and it is non-native, but seemingly not as invasive as the Himalayan Balsam. Does anyone have any advice as to whether I should remove the Orange Balsam as well as the Himalayan Balsam?

Edit: It seems that I should: http://canalrivertrust.org.uk/news-...g-out-for-invasive-species-on-the-ashby-canal

Carless said:

Having looked at photos, that's it. I've read up on it, and it is non-native, but seemingly not as invasive as the Himalayan Balsam. Does anyone have any advice as to whether I should remove the Orange Balsam as well as the Himalayan Balsam?

Edit: It seems that I should: http://canalrivertrust.org.uk/news-...g-out-for-invasive-species-on-the-ashby-canal

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I've seen it at various sites around London + doesn't appear to be invasive at all unlike its larger cousin. Think you'e quite safe leaving it be.

aeshna5 said:

I've seen it at various sites around London + doesn't appear to be invasive at all unlike its larger cousin. Think you'e quite safe leaving it be.

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I'm going to have a look at it this evening. If it has developed explosive seed pods already the point will be moot for this year. If I do leave it alone this year, then I'll get the chance to see how the patch has developed next year. Even Himalayan b. doesn't seem to spread much year on year, so leaving the Orange b. to see what happens is also likely to not be an unrecoverable situation.

It is a concern to me as some organisations online have said that Orange b. is invasive, and if I cleared the Himalayan b. only to have it supplanted by another invasive, that would be not good. Most of the patches of Himalayan b. that I've cleared have been replaced by nettles, bramble, various non-giant Umbelliferae, etc.

Having had a look at how many Orange Balsam seedlings are coming up in areas that have been cleared of Himalayan Balsam, Orange Balsam is definitely invasive.

Hmm.... Can't edit that post any more.

It seems that CABI have finally gotten around to releasing the Himalayan Balsam specific rust fungus which is likely to reduce the competitive advantage of Himalayan Balsam, and make it a much more benign plant. That means that the bashing work I'm doing now should eventually merge with the rust fungus making its way up here, and then won't be at risk of just going backwards if I stop doing it.

However, it seems that the fungus does not attack Orange Balsam.