This is a large aquatic perennial sedge, with tall rounded or triangular bright-green stems, growing up to 3 m tall. Instead of leaves it has thin papery sheathing bracts at the base of the stem, which produce small groups of flowers on drooping stalks near the tip. It grows from dense woody rhizomes buried in bottom sediments, usually in tidal reaches of large rivers like the Waikato and Northern Wairoa. It is very similar to the native S. tabernaemontani, which has bluish-green stems and erect flower stalks (not drooping).
It forms tall dense beds that colonise mobile sand deposits and river margins, where it may displace smaller native species.
What to do
Contact your regional council to determine the status of this species and responsibility for control and/or advice on control.
Page last updated: 24 March 2009