Publication: Rhodora. 66: 132, plate 1295, fig. 1. 1964.
selected vouchers: WTU
Notes: FNA7: "Subspecies americana appears to be the sole representative of Subularia in North America. It differs from subsp. aquatica, which is restricted to northern Europe and Russia, by having persistent (versus caducous) sepals, fruiting pedicels ascending at 30-50Âº (versus 50-90Âº) angles, and broadly ellipsoid to broadly obovoid (versus ellipsoid) fruits. G. A. Mulligan and J. A. Calder (1964) indicated that plants slightly intermediate between the two subspecies grow sporad-ically in North America, and it is not known whether they represent hybrids."