What's this plant?

[mothhawk]

Anyone got an idea? Is it a weed? I certainly haven't planted anything there. When it started to grow it had a rosette of leaves, and I told myself I must get that dandelion out sometime. Meantime it's growed, like Topsy.
For scale, on the left is peony, on the right is rosemary. What's the one in the middle?

[Two_Sheds]

Looks like a bolting leafbeet

[mothhawk]

Looks like a bolting leafbeet

Does it? I don't think it can be though. I've never grown leaf beet 'cos I don't much like it. The neighbours' gardens are barren wastes so it's not come from there.

If it helps, it's growing fairly near the bird feeder, but I don't feed mixed seeds. A distant thought - could it be a niger seed growing? Haven't had niger seed since winter 2011/2012 though. If not it must be a seed 'dropped' by a bird I think.

[binley100]

Many a strange thing grows from dropped bird seed

[Glutton4...]

It could be kale or even rape, from seed dropped by a bird...

[julesapple]

The leaves look shiny - I thought kale and rape both had greyish blooms on the leaves, apart from that it does look like either of them. Having said that, kale is kind of crinklier.

[veggiechicken]

Looks like a bolting leafbeet

I agree with TS - looks like perpetual spinach beet Spinach 'Perpetual' (Spinach Beet) - Brassica & Leafy Green Seeds - Thompson & Morgan

[mothhawk]

It's not kale, I have that growing elsewhere. The stem is squareish and the leaves are shiny green. I'll have a cautious nibble and see if it tastes like leaf beet. It hasn't put up any of the big leaves that beets do though. It started with 3 or 4 small leaves (maybe 4 inches long) in a rosette flattish to the ground, then whoosh, up came the stem. I'll leave it to flower - that may be more helpful in ID-ing it.

[mothhawk]

Had a nibble and it was quite bitter but had that penny-in-the-mouth aftertaste you get with leaf beet, so maybe you are both right Twosheds and Veggiechicken Will know for sure I hope, when it flowers.

[veggiechicken]

If you're lucky MH, it will selfseed before you notice and you'll have them everywhere - since you obviously like them so much

[mothhawk]

Always looking on the bright side VC?

I go out every day with camera in one hand and secateurs poised in the other. Since it's a guerrilla plant I'm taking no chances...

[mothhawk]

It's five feet tall now. Not a very clear picture I'm afraid (taken with my NEW camera and I'm still getting to grips with it!). That's a Jerusalem artichoke behind it.

[veggiechicken]

I'm not sure which plant you mean MH? Is it the one with ?seed heads immediately left of the yellow flowers?

[mothhawk]

Yes, that's the one - rudbeckia and rosemary to the right, JA behind and left, lobelia hanging basket, and a marrow at the bottom trying to get itself in shot too.

[veggiechicken]

Is it one of the Chenopodiums? ?Chenopodia?