Linum grandiflorum 'Rubrum', or scarlet flax, is a useful annual for mediterranean gardens. In our hot unirrigated garden in southern Greece it appeared originally from a sowing of "Yosemite wild flowers" - it actually comes from Algeria rather than California, but is apparently naturalised in some places there. It has self-sown and reappeared the next year, in a dry sunny corner in poor soil. It looks great with the sun behind it, and grows to about 30cm (one foot), flowering for us in March. Its colour is good against the local wild sage, growing behind it in the picture below.