Nectaroscordium siculum

[nikoroma]

http://www.ideasforgardens.net/nicola/nectaroscordium-siculum/index.html

[Palustris]

And yet another thug.
I have an albino form of this which one day I will manage to dig out from the plant it has self seeded into.

[ideasguy]

Nicola is not the only one to like this plant.
The Guardian once featured it as plant of the week on their website:-
http://www.theguardian.com/lifeandstyle/2011/sep/16/plant-of-week-nectaroscordum-siculum

However!! From Kew:
http://www.kew.org/science-conservation/plants-fungi/allium-siculum-sicilian-honey-garlic
They say:

Cultivation

Allium siculum is easily cultivated in ordinary soil, in sun or light shade. It can produce abundant seeds and become weedy. Its unpleasant smell can be detected at some distance from the plant.

They mustn't be too worried about the self seeding:

Allium siculum grows in the Director’s Garden at Kew.