Tufted shrublet branching from base, up to 30cm. Leaves linear to lanceolate, margins pinnatifid-dentate, slightly rolled under. Bears 1 to few large, hairless, usually dark blue flowers, on wiry leafless stalks 10-28cm long.

Lobelia chamaepitys has mostly solitary, smaller flowers, 10-16mm long, on stems 7-12cm long.