Kingdom: Plantae
Division: Pteridophyta
Class: Pteridopsida
Order: Blechnales
Family: Blechnaceae
Species: Blechnum
Scientific name: Blechnum novae-zelandiae
Common name: Parm-leaf fern, Kio kio, Kiokio Blechnum Capense,
Kiokio (Blechnum novae-zelandiae) it can be found growing abundantly on clay banks along roadsides and rivers. The long cascading fronds (up to 2m long and 50cm wide) are a bright pink colour when new, and turn light green and then darker green as they mature.
Blechnum novae-zelandiae is an endemic fern of New Zealand. It belongs to the family of hard ferns, the second largest of New Zealand’s fern families. Once it was formerly known as Blechnum capense.
It is a common fern found throughout New Zealand. It is frequently seen on roadside banks and in forest gullies as well as in scrub and swamp. It has long cascading fronds (up to 2m long and 50cm wide) are a bright pink colour when new, and turn light green and then darker green as they mature. The new fronds have red tones in the sun. Blechnum novae-zelandiae has fertile and sterile fronds of different form on the same plant. During every growing season, some adult ferns form:
Sterile fronds that lack sporangia
Fertile fronds that bear sporangia
The two types of fronds often differ in appearance, a condition known as frond dimorphism (di= two; morph= form). Frond dimorphism is found in many genera of New Zealand ferns. Those of the fertile fronds are much reduced in width and have a black row of sporangia at each leaflet margin
Blechnum novae-zelandiae on the bank upper Te Henui walkway
When young, many fronds (both sterile and fertile) are rich in unmasked red pigments (anthocyanins). As they mature, green chlorophyll predominates.
The mature fronds have turned green
Sterile and fertile fronds - Leaflets (pinnae) on sterile fronds are 5-10 mm broad while those of the blackish fertile frond is 2-5 mm across. Both the sterile fronds and the fertile fronds are elliptic in shape and seldom exceed 250 cm in length.
The blackish fertile frond.
The upper surface of a fertile frond
The underside of a fertile leaflet
The underside of a fertile leaflet - The leaflet is only wide enough to bear sporangia in one continuous row on each side of the midrib. Prior to spore release, the covering (indusium, attached on the side nearest the frond margin) pulls back from the midrib to expose the sporangia. Large scales are attached to the midrib. 
The underside of a sterile frond
New frond developing
Two new fronds unfurling.
Thanks to Wikipedia for text and information:
