September in the hills with Chris Horne and Michele Dickson
Lastreopsis hispida, pongaweka, tuakura, hairy fern
Lastreopsis hispida is one of four similar-looking ferns in the Lastreopsis genus, within the large fern family Dryopteridaceae. It is notable for its bristly hairy stalk/stipe which distinguishes it from the other three species.
For general comments about ferns, see Asplenium oblongifolium in the October 2015 Tramper, and a description of the life cycle of ferns in Asplenium bulbiferum in the December 2015 Tramper.
Origin of the botanical name
Lastreopsis is derived from‘lastrea’, a fern known to the ancient Greeks, and ‘opsis’ from the Greek word meaning ‘looks like’; ‘hispida’ comes from the Latin word ‘hispidus’ meaning ‘bristly, with stubble’. Lastrea was named af ter Austrian botanist Charles Jean Louis Delastre (1792-1859).
Distribution and habitat
Hairy fern is common on Te Ika a Māui/North Island, in coastal regions on Te Waipounamu/ South Island, on Rakiura/Stewart Island and Rekohu/Chatham Island. It can be found on the forest floor in coastal to lower montane forests and occasionally as an epiphyte perching on the lower trunks of trees and tree-ferns. Hairy fern also grows in Australia; thus it is a New Zealand native species, but it is not endemic to New Zealand.
Pongaweka is a terrestrial fern with creeping rhizomes. The finely divided, brownish-green, egg-shaped fronds are 18 cm-50 cm long x 15 cm- 40 cm wide. Their harsh feel results from the black bristly scales and tiny brown hairs on the veins and midribs. The fronds contain a compound which acts as an insecticide which protects them from damage by insects. The stalks/stipes are 12 cm-50 cm long. The stalks, stems/rachises and rhizomes are covered with long, black, bristle-like scales and tiny glandular hairs. Run your fingers up or down a stalk to feel the rough surface.
When mature, clusters of sporangia make up the round sori on the underside of the fronds, as in the image above. These are in one row either side of the midrib away from segment/pinna margins. At first they are covered by a kidney-shaped covering/indusium which falls off as the spores ripen. The spores are spread by the wind.
We have not found any records of uses of hairy fern. Please tell us if you know of one.
Where to find pongaweka/tuakura?
You can see pongaweka in Wellington’s Burrows Avenue Reserve, Huntleigh Park, Johnston Hill Reserve, Ōtari-Wilton’s Bush, Post Office Bush and two of Wellington Botanic Garden’s bush areas. It also occurs in Hayward Scenic Reserve, East Harbour Regional Park, Akatarawa Forest and the Tararua, Remutaka and Aorangi ranges.