Tall, rigid perennials; rhizome thick, creeping. Stem leafy; cauline leaves terete, non-septate, acute; pith of astericiform cells; vascular bundles confined to the surrounding parenchyma. Stomata sunken. Lower bract not an apparent prolongation of stem. Inflorescence terminal, cymose, supradecomposite. Flowers borne singly; floral bracteoles present. Stamens 6. Seeds faintly reticulate; appendages Lnot developed.