Prickly Sheild fern (Polystichum vestitum)
Species: P. vestitum
Binomial name: Polystichum vestitum
Synonyms: Polypodium vestitum, Aspidium vestitum, Polystichum venustum, Aspidium venustum.
Common name: Prickly Sheild fern, Puniu
Polystichum vestitum is a very cold hardy fern. It has long, dark green fronds which are almost prickly to touch. It will slowly increase in size to form a clump. It is a terrestrial fern with an erect and scaly rhizome, sometimes forming a short trunk and growing up to 700 mm in height. The fronds are 220–600 mm long. There are 3–7 (usually 5) round sori on each pinnule, halfway between the margin and midrib, with a light brown indusium.
The fern is native to the three principal islands of New Zealand and the Chatham Islands, as well as to New Zealand’s subantarctic Snares, Antipodes, Auckland and Campbell Islands, and to Australia’s Macquarie Island. On Macquarie it dominates the fernbrake communities which typically occur on the eastern, leeward side of the island on valley slopes and sheltered valley floors. Although it can form dense stands in which few other plants will grow, more commonly it is found in conjunction with Stilbocarpa polaris, Poa foliosa and Pleurophyllum hookeri. The fern is seriously affected by rabbit grazing.
Photographed at Otari Wilton Bush Reserve, Wellington.
The hardy fern was photographed on Denniston's mountain plateau West Coast, South Island.
The underside of a sterile fern (no sori)
Top surface of sterile frond.
Topside of fertile frond
Underside of fertile frond
Underside with ripe sori