Lobelia linearis, in Afrikaans the sleutelblombos (key flower bush), is a shrub of about 70 cm in height that resprouts after fire. It grows many rigid, erect branches in a grass-like tuft. The leaves are mainly low on the grey-green stems and sometimes, when in bloom, there are hardly any leaves on the plant at all. Whatever leaves are present, are narrow, linear as the name says, up to 2 cm long and sometimes pinnately divided into thread-like segments.
The habitat of this plant lies in the Western Cape from the Cederberg, spreading eastwards coastally into the Eastern Cape to around Kareedouw. Rocky and sandy slopes, also renosterveld, where rain comes in winter and the summers are dry, are home to this species. The plants are heavily browsed, especially when the stems are young (Vlok and Schutte-Vlok, 2010; Manning, 2007).