Name that flower: it's a clematis

Clematis
Photo by Lee Lageschulte

So there's no question. The beautiful flower photographed by Lee Lageschulte is a Clematis, variety "Nelly Moser".

Thank you to all the gardeners and flower enthusiasts who answered my question.

Some comments:

The photo by Lee Lageschulte is a clematis. Probably others have identified it as well. It is quite common and well known to gardeners. It comes in many different colors and each is a named variety.

And someone had to ask a new question!

So it's definitely a "clematis" - but do you pronounce it "klem'-a-tis" or "clem-AH'-tis"?

This is a clematis, too
Photo by Marj Ando

Fortunately, someone else answered:

clematis |ˈklemətəs, kləˈmatəs| 

noun

a climbing plant of the buttercup family that bears white, pink, or purple flowers and feathery seeds. Several kinds are cultivated as ornamentals.

[Genus Clematis, family Ranunculaceae.]

ORIGIN Latin (also denoting the periwinkle), from Greekklēmatis, from klēma ‘vine branch.’

And some detail:

It's a clematis. The one blooming on my desk, named 'Mrs. N. Thompson', has large variegated purple blossoms. It grows in a big pot with other plants, likes sun and climbs up an "artsy" pole that was purchased at Garden Essentia located at Ballinger Terrace next to Thriftway. Clematis are a perennial so it blooms every spring.