Annual or perennial herbs, some with woody lower stems. Stems with distinct nodes and internodes. Leaves alternate, with conspicuous leaf sheaths; leaf sheaths open or closed. Flowers usually on scorpioid cymes, cymes solitary or in integrated panicles, some elongated and typical, some shortened into capitula, some sessile and with clusters of flowers, even some reduced to single flowers. Terminal or axillary, axillary cymes sometimes penetrating the leaf sheaths in which they are wrapped and exserting the sheaths. Flowers bisexual, rarely unisexual. Sepals 3, separate or united only at base, often navicular or keeled, some apically galeate. Petals 3, separate, but in Cyanotis and Amischophacelus the petals are united into a tube at the middle and remain separate at the ends. Stamens 6, fertile or only 2-3 fertile with 1-3 staminodes; filaments with moniliform hairs or glabrous; anthers parallel or slightly forked, longitudinal slits dehiscent, rarely apical pore dehiscent; staminodes apically distinct (4-lobed butterfly-shaped, or 3-lobed, or 2-lobed forked dumbbell-shaped, or undivided); ovary 3-locular, or reduced to 2-locular, with 1 to several orthotropous ovules per locule. Fruit mostly a loculicidal capsule, sparsely berrylike and indehiscent. The seeds are large and few, rich in endosperm, with the umbilicus striped or punctate, and the embryo cover (the umbilicus-like object under which the embryo is located) situated on the dorsal or dorsolateral side of the umbilicus.

Perennial or sparsely annual herbs, often with mucilaginous cells or mucilaginous tracts. Stems erect or creeping, with conspicuous nodes. Leaves alternate, with leaf sheaths. Inflorescences usually scorpioid cymes, or inflorescences shortened and flowers clustered or capitate, or elongated, forming panicles, rarely solitary. Flowers bisexual, rarely unisexual; sepals 3, usually separate; petals 3, mainly blue or white, usually separate, some joined at middle to form a tube and separated at both ends; stamens 6, fully fertile, or only 2-3 fertile and 3 staminodes, staminodes are a rather important feature in this family, their morphology and arrangement varying considerably in different genera, and the filaments are often moniliform with long hairs; ovary superior, 2-3-loculed, each with 1 to 1 to 3 hairs. Ovary superior, 2 to 3-loculed, with 1 to several orthotropic ovules per locule. Fruit a capsule, sometimes indehiscent but often berrylike. Chromosome base = 4 to 29.

The stem of this plant is slender, nodding; the leaves are alternate, with conspicuous leaf sheaths; the flowers are bisexual, the calyx and perianth are separate, and the flowering is very short, continuing only for a day; the fruit is a capsule, and the seeds are ribbed.