I’ve been seeing Cyperus ustulatus around wetland areas in Tauranga for a few years, but was never sure if it was a “desirable” native or a self-seeded weed, maybe a member of the papyrus family.
Turns out I wasn’t far wrong! A profile of the plant on the Tiritiri Matangi website reveals that it is a cousin to Egyptian papyrus and also known as coastal cutty grass.
The clumps are used as habitat by lizards and ground-nesting birds. And yes, the leaves are sharp edged so a planting of these is a horticultural “keep out” sign that is well heeded.
Maori call it upoko-tangata and used the leaves as an outer thatching for their whare (dwellings); or, stripped of their sharp edges, for weaving mats and baskets and for kite making. An upoko-tangata kite featured on a set of matariki (Maori new year) stamps in 2010, given the $2.30 value.
Olga Adams in a 1945 article for the Auckland Botanical Society Bulletin noted that in North Auckland districts the pith was boiled with water, strained and bottled and used to ease kidney trouble.
The word upoko means “head” while tangata is “people” so perhaps Cyperus ustulatus got its te reo name from its use as a thatching material.
As a garden plant, this one comes with a warning as this website notes: “Easily grown from fresh seed, and often self sows in gardens. A quite attractive plant now popular in cultivation. However it should be planted with caution, the leaf, margins are very sharp and can cause very deep cuts.”
It prefers damp areas (hence all the wetland planting), full sun and doesn’t mind a touch of frost. It is described as “vigorous” and certainly looks it.