Sweetly scented, rampant, and evergreen.

Zantedeschia "Gem Lavender"

A sterile hybrid, which doesn't die after flowering.

Looks more of a salmon pink in the flesh

This is one of the first flower spikes, and just 3-4' tall. By late autumn, the flowers were 7' tall.

Ipomoea alba - sweetly scented, nocturnal cousin of Morning Glory

The flower (including the calyx) is 30cm (1 foot) long. The strong, citrus scent of a single flower can be smelled from several feet away; when it produces its main flush of flowers, the whole garden is filled with the intoxicating scent.

The flowers are much larger than the annual morning glories, they stay open longer each day, and it carries on much later in the season. It's also perennial if you have the right (micro)climate.

...with Buddleja glomerata "Silver Service" in the background

An unlikely survivor of the 05/06 winter. Even in London, it needs a very sheltered spot, and will suffer quite a lot of die-back in winter (but quickly grows back in late spring).

Alyogyne huegelii "Santa Cruz"

It only just survived 05/06 winter, and took so long to recover that sporadic flowering didn't begin until autumn. I'm hoping that it'll fare better now that it's well established.