Tall plant with small yellow flowers

Many thanks for the clear new pics. Much appreciated.
Are you in UK or USA....I see a 10 Cent coin?
I am not familiar with many species of Oenothera

But wiki says Quote....."One of the most distinctive features of the flower is the stigma, which has four branches in an X shape."

The pics below shows this very clearly.

oenothera flower - Google Search:

oenothera flower - Google Search:

oenothera flower - Google Search:


Now my problem is that I am not seeing this on your flowers.
The stigma on your plant appears as a big round blob...not 4 branched.
I am now stuck.

 

Well, I wouldn't like to say which species, but I would go along with evening primrose, Oenothera, mainly looking at the unopened buds.

On the subject of uploading pics there are lots of ways of doing it, I stopped using hosting sites immediately GC got their own upload button.

I alway put pics from my camera into a folder on my PC.

after that I just click on "upload a file" at the bottom of the page, a window opens showing files on your PC, I just work out which one I want, click on it and then click on "open"it then automatically uploads it to the GC site.
You just then have to click if you want full pic or thumbnail.

 

By the end of the summer the stems are so woody it could be a small tree and the plant is three metres high. Tint, tiny flowers with no discernable smell. It must be the worst example of Evening Primrose going :(

 

The only Oenothera I can find at around that height is this one, but little else about it seems to make much sense.

Tall Yellow Evening Primrose, Oenothera Longissima

You haven't mentioned your location!

Nick

 

Hmm!. Oenothera longissima may be tall but nothing what so ever is a match.
Mystery plant has tiny flowers.

Not at all sure that we have solved this..yet it has been marked solved.

 

Yep, for me to consider a plant correctly identified we at least have to establish what the species is! Not necessarily the cultivar as there can be some extremely similar ones with some species. Not even sure this is an Oenothera, very puzzling!

Nick

 

The OP said that "the plant is three metres high."

So this is growing to twice the maximum height of Common Evening Primrose (1.5m) and the flowers are smaller! An undiscovered species?

Nick

 

Excuse me but Berberis Artista has already done this .added by wiseowl on 4th July .....using a 10 cent coin.

 

Yep, and these are just under 2cm in diameter.

10 euro cent coin - Wikipedia

Flowers of biennis are 4-5cm across.

Nick