Leaves alternate, entire or deeply divided, sessile or petiolate, linear to narrowly oblanceolate.
Shrublets or perennial herbs 0·2–0·6 m. high, with pellucid gland-dots on all parts.
Inflorescence of terminal or axillary racemes or panicles.
Stamens 8, inserted at the base of an annular disk.
Fruit a capsule dehiscing ventrally by a slit.
Flowers bisexual, 4-merous, pedicellate.
Seeds echinate.