A literal translation of Helianthemum yields sun-flower (Helios = sun and Anthemon = flower), but I've never heard sunflower refer to anything but the genus Helianthus. Instead of sunflower, this plant is commonly known as sunrose or simply helianthemum. It is in the same family as Cistus ladanifer from a few days ago.
Stewart Hinsley has a page on Helianthemum cultivars that displays the diversity of colour in garden plants, while Ketzel Levine from NPR and Paghat talk about the plant in the garden.
Botany / evolution resource link: I've had a few people recommend this news story to me: Colorado University Study Shows Novel Structure In South Pacific Plant May Be 'Missing Link' In Evolution Of Flowering Plants explains that research into Amborella (long considered a “living fossil” angiosperm or flowering plant) continues to reveal hints about the early evolution and development of the angiosperms.
Helianthemum 'Henfield Brilliant' - Z6 - RHS Index of Garden Plants, Griffiths
Helianthemum 'Henfield Brilliant' - Z6-8 - A-Z Encyclopedia of Garden Plants, Brickell, Cole, Zuk
Awesome color! I want some of this in my garden. Now I'm off to see if it's available, even as an annual it would be worth the effort.
Look for the interesting bicolor "Merrist Wood Cream". Think raspberries with clotted cream.
Beautiful contrast! I love the depth of this photo.