Myriophyllum pinnatum (Walter) Britton, Sterns & Poggenb.

Lvs partly or largely alternate or scattered, 1–3 cm, with capillary segments; emersed lvs sometimes developing and resembling the bracts, these chiefly whorled, much exceeding the fls, to 18 mm, with a flat rachis to 1 mm wide and on each side 3–5 ascending teeth 1–2 mm; spikes emersed; fr 2 mm, deeply lobed, each mericarp bearing a flat or concave longitudinal ridge with sharply tuberculate margins. Mass. to O., Io., and S.D., s. to Ga. and Tex., more abundant southward. (M. scabratum)

Can be grown by cuttings.