Linum grandiflorum rubrum.
Once established this variety can tolerate immense heat and extremely dry conditions. Reseeds readily, but is never a nuisance.
Produces bright, glossy, scarlet colored flowers that are 1-1.5 inches on 1-1.5 foot plants. This species, with brilliant red petals often edged in black, is a close relative of the flax used to produce linen. Sow seed in fall in mild winter areas, early spring everywhere else.