Is this Hemp?

sampullman

Recent newspaper reports brought me to this forum. I read that a mystery plant was identified as being hemp probably grown from bird seed. I have a similar intruder and it has grown to about five foot high in as many weeks.

It has needed support to keep it on the straight and narrow and appeared in my greenhouse where I have kept it watered while I waited for a flower to appear. It looks very much like the pictures I've seen but the leaves on mine seem wider and not as spikey.

I hate killing any plant especially one that has kept me so entertained and curious for the last month. I'd be grateful for opinions on the identification. Thanks.

Hostafan1

teasel? but Ithink teasel is spiky, so probably not

sampullman

Thanks Hostafan1
I can see some similarities and the height of some of the Teasel photos I've seen certainly seems to be on the right track.

I'm still open to suggestions though. Thanks for your thoughts.   

sampullman

Here is a better photo showing the underside of a leaf as well 

Dovefromabove

Looks like Himalayan balsam ... an
introduced highly invasive plant which is causing a lot of problems in the countryside and causing the eroding of riverbanks. 


https://www.rhs.org.uk/advice/profile?pid=480

https://www.plantlife.org.uk/uk/discover-wild-plants-nature/plant-fungi-species/himalayan-balsam

https://www.waterways.org.uk/news_campaigns/campaigns/himalayan_balsam/himalayan_balsam

Silver surfer

Don't think it is Impatiens glandulifera...Himalayan balsam.
The leaves of which have stalks.
Plant in thread doesn't appear to have any stalk.

https://www.google.com/search?q=impatiens+glandulifera+leaves&client=firefox-b-d&source=lnms&tbm=isch&sa=X&ved=0ahUKEwisw-bT4fHkAhVDrHEKHTarBYUQ_AUIESgB&biw=1920&bih=944

Paul B3

Maybe a Eupatorium spp.???

sampullman

All great suggestions thank you, and each one has some spark of recognition. I'm glad that so far no mention of it being hemp but @Dovefromabove has me a bit worried. The Himalayan balsam looks very similar (great links by the way!) and I wouldn't hesitate to get rid of it if I was convinced.

However, @Silver surfer has made a great observation regarding the stalks and I think the Balsam leaves are much rounder than what I have growing. Nice attention to detail thanks!

The latest suggestion from @Paul B3 is another good one and covers a broad range of choices lots of which have valid possibilities.

Maybe worth me pointing out that this started life in a 12cm pot and when I transferred it to a 25cm pot it had a tight and extensive root system that kept the shape of the smaller pot. At the moment the stalk is green and there are smaller leaves starting to grow in the joints of the bigger ones. Latest photo attached.

Thanks to everyone for the great advice any further info will be gratefully accepted.

Dovefromabove

If there are prickles then
its not Himalayan Balsam.

Are there any prickles on the backs of the leaves or bristles on the stem? ... if so Ill go with teasel. 

Silver surfer

sampullman your pics are super and really clear.
Prickles have not been mentioned.?
I am not seeing any prickles on stems or leaves.
So believe  teasel this can be ruled out completely.
Below are pics of Teasel.

I am struggling with Eupatorium to find evidence to prove /disprove this good suggestion.

I think you may need to wait until 2020 when your plant produces flower...then it will all be clear and you will get an accurate id.
Do please add fresh pics to this thread when things change.
Please

sampullman

Thanks again for further input. I can confirm no prickles or spikes on the leaves or stem.

I will certainly update any developments and try to keep it alive until it flowers. If it's something that looks nice and is safe to have around it would be a good one for kids to get involved with because the growth rate is twice as good as a sunflower.

The mystery continues ....