In The Hills In The Hills 2016-06

Blechnum fluviatile < Species index > Blechnum penna-marina

This article was first published in the Tararua Tramper Volume 88, no 5, June 2016

June in the hills with Barbara Mitcalfe and Chris Horne

Blechnum novae-zelandiae, kiokio

Distribution

Kiokio is endemic to New Zealand. You are sure to have seen this common fern, the largest member of the Blechnum genus, and one of our larger ground-dwelling ferns. It grows on the Kermadecs, Three Kings, North, South, Stewart/Rakiura, Chatham/Rekohu, Auckland, Campbell and Antipodes islands. You will see kiokio throughout its widespread range: lowland to subalpine forest, boggy to dry open ground, and even rocky places. It often forms dense colonies in gullies and on track-side banks. It is particularly abundant on road cuttings on the West Coast, where it helps to prevent severe erosion during rain-storms.

Form

Kiokio – four fronds, three sterile, one fertile Photo: Jeremy Rolfe

Kiokio has a short-creeping rhizome. The stalk (stipe), 8-70 cm long, is stout, pale brown, and covered with pale-brown scales with dark centres.

The sterile fronds are green on top, paler green underneath, harsh to your touch and from 20-250 x 8–60 cm. They have 10-50 fine-toothed, segments, crowded in pairs and attached to the stem (rachis), which has scales similar to those on the stalk. You may notice that young kiokio fronds are often tinged with red or pink, thought to be a protection against strong ultra-violet light.

Kiokio's fertile fronds are quite different from its sterile fronds, a characteristic of the Blechnum genus, as you read in the April 2016 article. They are 15-50 cm or more long and 8-20 cm wide. You will see on the top right of the image a fertile frond, with numerous pairs of black, wire-like, fertile segments, and below them, about eight pairs of sterile segments.

Reproduction

Sori, which bear the spores, cover the undersides of the segments. When the sori mature, the spores within them ripen and are spread by the wind, to germinate and produce more kiokio. In the December 2015 article is a description of the several stages of the development of adult ferns.

Uses

Kiokio koru/fiddleheads are edible, raw or cooked. Māori used to wrap vegetables, e.g., kumara, in kiokio fronds, to add flavour to the hangi.

See also

Category

Botany 2016

In The Hills 2016-05 < Index chronological > In The Hills 2016-07