Lobelia

Lobelia is a genus of herbs (rarely annuals) and subshrubs in the Lobeliaceae family, previously Campanulaceae. The plants are sometimes wiry or appear leafless.

The often toothed leaves may grow alternate, opposite or whorled, in some cases directly from the ground.

The flowers are borne in leafy spikes or racemes, in some species axillary and solitary or clustered at stem-tips. The calyx is shorter than the corolla, its lobes hairy or roughly scaly and in some species oblique.

The two-lipped corolla is cleft to its base. The small upper lip is two-lobed or consisting of two free petals, the larger lower lip three-lobed or comprising clawed petals. Flower colour is often blue or purple, sometimes white.

The five stamens are usually attached to the corolla base, rarely higher up, alternating with the corolla lobes. Lobelia ovaries may be inferior or superior, each comprising two locules. The style is linear; in few species it has a hairy collar below the stigma that is two-lobed and hairy.

The fruit is a two-valved capsule containing many seeds, the calyx often persisting upon it.

There are about 300 species, 70 of which occur in southern Africa.

The plant in picture is Lobelia cuneifolia (Leistner, (Ed.), 2000; Manning, 2009).