Like perennial blue flax, annual scarlet flax seed is shiny, a clue to the fact that flax seed is used to produce linseed oil. This species, with brilliant red petals often edged in black, is a close relative of the flax used to produce linen. (Note both “linen” and “linseed” derive from botanical name, Linum.) See related species, Blue Flax, Linum perenne lewisii.