Ericoid shrubs. Stipules adnate to petiole and sheathing the stem. Leaves 3(-1)-foliolate. Flowers unisexual, single in axils. Petals 0. Male flowers: 4 petaloid calyx lobes and (usually in ours) 4 stamens. Female flowers: calyx lobes 4, connate below into a tube. Styles 1-2; stigma lacerate-multifid. Achenes 1-2, enveloped by the inflated persistent calyx tube.