Great call, Bob... and as you say, for a self-seed (bird's help or not)
that's a beauty. :-)

Bob Hobden wrote:

"Imageman"
Please help with an ID of this lovely flower. Must have been donated by a
bird, and it's welcome to stay. I'd like to get some more of them -
Thanks,

Alstroemeria or Princess Lily and a rather nice self-seeded one at that.
Fully hardy perennial with a long flowering season that will gradually
increase in size, even move itself around the border over time, but is
never badly behaved. Classy garden plant.
They are available in a range of colours and heights, I have some that
only grow to 6 inches ** and another that grows to 4 or 5 ft.
** Flowers of the short ones are loved by slugs and snails so be warned.