Fr orbicular to ellipsoid, strongly flattened laterally, its ribs evident to obsolete, the secondary ones not developed; each mericarp with a layer of sclerenchyma surrounding the seed-cavity; carpophore wanting; peduncles axillary, elongate to nearly obsolete, bearing a simple umbel, or the umbel proliferous into an interrupted (sometimes forked) spike; invol small or none; sep minute or obsolete; pet white in our spp.; small perennials, the slender stem prostrate or arched and rooting at the nodes, with simple, long-petiolate, broadly ovate to orbicular or reniform, sometimes peltate lvs. 75, mostly warm reg.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
