Alisma lanceolatum With.
Stems stout, erect, to 1 m high; rootstock short, stout. Leaves all basal, erect; laminae 7-23-(28) × (1)-2-5 cm, lanceolate, gradually tapering to subacute tip, gradually narrowed to long petiole. Inflorescence a much-branched panicle; branches whorled, ± straight, usually ascending, basally bracteate. Flowers usually pink, 1 cm diam., pedicels slender, bracteate; sepals ovate; petals ± acute. Achenes c. 20, c. 2.5 mm long, rounded, compressed, in a dense circular head; persistent style from above middle of inner edge of achene, curved in lower part, stigmatic portion occupying ½-⅔ of style-length.
N. Hawkes Bay - Wairoa, near Napier, Havelock North; Wellington - Manawatu, Waira-rapa, Hutt Valley. S. Canterbury - Christchurch and environs, Rangitata River mouth, near Washdyke; Otago - Taieri, Lake Waihola, Milton, Tokomairiro. Occasional on edges of creeks, pools, ditches and drains, and at muddy river mouths.
(Europe, N. Africa, W. Asia)
First record: Colenso 1895: 402, as "Alisma plantago Linn."; much later recorded as A. lanceolatum With. by Healy 1968: 285.
First collection: Hawkes Bay, H. Hill, [1892 or 1893] ().
FL. 12-1, FT. 2-4.