herbs or herbaceous shrubs. Leaves spirally arranged, 3-5 nerved from the base,
serrulate, with entire or lobed margin. Inflorescence cymes, opposite the leaf.
Flowers hermaphrodite, 5-merous. Sepals free, hairy outside, glabrous inside.
Petals free, united in a tube when young, glabrous, glandular at the base.
Stamens free, anthers dorsifixed, subglobose, opening lengthwise, staminode
absent. Ovary 2-5 locular, each locule with 2 ovules, styles subulate, stigmas
pointed. Fruit a capsule, wingless, not lobed, pericarp spiny, indehiscent.