This photograph is courtesy of John Harvey. I'd previously suggested John's site as a photo resource link, including the section on Learning Photography. John participates from time to time on the UBC Botanical Garden Forums, where he submitted this (and other) photos via the BPotD Submissions Forum. Thanks John!
I don't think I can add much to what Richard Hebda of the Royal BC Museum has written about showy Jacob's-ladder, so I suggest visiting that web page to learn more. Since the species occurs in Washington state, the ever-reliable Burke Museum of Natural History and Culture has a section on Polemonium pulcherrimum with a variety of photographs.
Polemonium pulcherrimum - Z4 - RHS Index of Garden Plants, Griffiths
Polemonium pulcherrimum - Z4-8 - A-Z Encyclopedia of Garden Plants, Brickell, Cole, Zuk
Jacob's-ladder is a lovely, understated plant. I had several, spread about in a previous garden. The flowers are quite beautiful and delicately coloured (as this photo shows), but the individual flowers are small and easy to overlook unless you really home in on them.
I'd be interested to read what Richard Hebda has written, but the link above seems to be obsolete.
Whoops, should have searched first -- the article on Jacob's-ladder seems to be here http://www.bcarchives.bc.ca/Natural_History/Plants.aspx?id=973
... and is good reading for anyone who appreciates this plant.