June in the hills with Chris Horne and Michele Dickson
Gahnia setifolia, māpere, cutty grass
Gahnia setifolia, endemic to New Zealand, is a close relative of G. pauciflora, also a sedge, which was described in the May In the Hills.
Sedges and grasses
Plants are classified into families, genera and species by botanical taxonomists, based on their mode of reproduction. The sedges are in the Cyperaceae family which in New Zealand includes thirteen genera. There are six members of the Gahnia genus in our flora. The differences between sedges and grasses are described in the article on the sedge Carex uncinata in the June 2012 In the Hills.
Origin of the names
Gahnia is named after Swedish botanist, Henric Gahn (1747-1816); setifolia comes from Latin and means ‘with narrow or bristle-like leaves’. Its Te Reo name ‘māpere’ is usually restricted to this species but is sometimes used for G. pauciflora. The name ‘cutty grass’ describes the sharp edges of the leaves but incorrectly names the plant a ‘grass’ – it is a sedge! Many trampers have had their legs scratched when tramping through areas of dense cutty grass/māpere.
Distribution and habitat
Māpere/cutty grass is present throughout Te Ika a Māui/North Island although it is less common in the central area. In Te Waipounamu/South Island it occurs in Marlborough and Nelson. Look for it in well-lit forest and scrub up to 450 m above sea level.
Māpere/cutty grass forms stout, distinctive, densely-tufted clumps 100 cm - 250 cm tall, rising from thick, woody root-stocks. The leaves, tapering to very slender tips, have rough, inward-rolled edges. The stout, smooth culms/flower stalks, are c. 15 mm at the base and up to 10 mm diameter above it and up to 90 cm tall, much branched and held above the clump.
Māpere/cutty grass flowers in December and January. They are dark red-brown or blackish-brown, growing on panicles/branchlets, 40 mm-70 mm long, which droop from the culms. The nuts/fruit produced by the flowers have a chaffy covering which is white at first, later becoming dark red-brown. The nuts are 3.5 mm-4.5 mm long x < 2 mm in diameter. They are shiny, elongated egg-shaped, oval around the middle, and yellow-cream when immature, then reddish-brown all over.
When chewed gently, the dark-coloured nuts may have a raspberry-like or vanilla flavour, depending on perception.
We have been unable to find any rongoā/medicinal or other uses of Gahnia setifolia. If you know of any, please tell us. Gahnia species are host and food plants for the rare forest ringlet butterfly/Dodonidia helmsii.
Where to find māpere/cutty grass
Look for it in the Remutaka and Tararua ranges, and the Eastbourne and Eastern Hutt hills, e.g., Horoeka St Reserve, Stokes Valley, particularly in places with light overhead cover. It is uncommon in western Wellington’s hills.