Fls axillary, solitary, 4-merous. Calyx deeply 4-fid, persistent; corolla subrotate, a little > calyx, with very short tube and 4 lobes imbricate in bud. Stamens 4, inserted between corolla-lobes; anthers 2-celled, dorsi-fixed. Ovary 4-lobed to base; style long, gynobasic. Fr. of 4 setulose nutlets rounded at back and apex; seed erect, embryo cylindric, endosperm cop. Minute creeping herbs with opp. lvs. Family of single genus with 2 known spp., one endemic to Patagonia, one to N.Z. For a discussion of their claim to family rank see Skottsberg (Engl. Bot. Jb. 48, 1912, 17-26).