Flora of New Zealand Series

Type locality: "Taupaki, Kaipara, N. Island, N. Zealand." Type: "Univ. Mus. Christiania. No. 3154, leg. T. F. Cheeseman –/3/84, com. A. Bennett." AK 108158 is probably part of the original collecting.

Rhizome little-branched, us. buried in firm mud; lfy branches erect, us. simple, long or short, often rooted at lf-bearing nodes. Stipules c. 2–3 cm. long, free, open, membr. and often conspicuous. Lvs entire; lower lvs apparently not regularly submersed and not clearly distinct from upper lvs though often more narrowly elliptic and with fewer, more obscure nerves; upper lvs long- or short-petiolate, lamina 1.5–6 × 0.8–3.5 cm., broad-elliptic or occ. oval, subacute and sts shortly attenuate at tip, firm and opaque, longitudinal nerves (11)–13–21 in all, us. several laterals emerging from midrib. Peduncles arising in axils of upper lvs, simple, stout, erect, standing well above lvs. Spike 1–2 cm. long, dense. Achene c. 2 × 1.5 mm., neither flattened nor strongly keeled, beak short but slightly curved, ± red when ripe.

DIST.: N., S., St.

In ponds, swamps and boggy places.

FL. 12–2. FT. 1–3.

This is the plant referred by earlier authors to the N. Hemisphere P. polygonifolius Pourr. from which it differs, inter alia, in the smaller, relatively unkeeled fr.