or ascending perennial succulent herbs. Leaves opposite or alternate, simple,
entire or deeply incised. Flowers erect, in many-flowered sub-paniculate cymes.
Sepals 4-fid. Corolla 4 petals, united, forming flask-shaped tube with
spreading 4-fid limb, much exceeding calyx. Stamens 8, in 2 series, adnate to
corolla tube. Carpels 4, adnate to base of corolla tube, narrowed into exserted
styles, stigmas obliquely truncate. Fruits many-seeded follicles.