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1 Leaf blades 2.7-5× as long as wide (or even narrower on submerged leaves), tapering at the base; petals pink, 2.3-3.7 mm long; achene with a dorsal ridge flanked by two dorsal grooves
1 Leaf blades 1.3-2.5 (2.7)× as long as wide, rounded to subcordate at the base; petals white, either 1.8-2.5 mm or 3.8-4.5 mm long; achene with a single dorsal groove.
..2 Petals 1.8-2.5 mm long, 1.4-2.0 mm wide; infructescences 2-4 mm in diameter; achenes 1.5-2 mm long