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NZ Plants

Blechnum parrisiae - pukupuku, rasp fern

Hard fern family: Blechnaceae

Blechnum parrisiae is a small fern with a short erect stem bearing similar fertile and sterile fronds that are reddish when young and rough and raspy when mature.
A fern occurring on the Kermadec Islands, the North Island and offshore islands and on the South Island forming extensive colonies in exposed areas.
Formerly known as Doodia australis.

Vegetative characteristics

Fertile frond and sporangia

Plant form: an erect stem bearing stiff, harsh fronds up to 600 mm long

Frond appearances: similar to sterile fronds

Frond stalk, midrib: scales present on frond stalk (stipe) and midrib (rachis)

Sporangium location: on lower frond surface

Frond shape: narrowly elliptic to linear

Sporangium position: leaflet margin

Frond blade: pinnate (divided 1 x into leaflets or pinnae)

Sporangium distribution: in groups (sori)

Frond surface: harsh, fine hairs

Sorus shape: linear, discrete,sometimes running together

Leaflets: oblong shape, tip rounded to pointed; lower ones stalked, the middle and upper attached along their base (adnate)

Sorus covering: linear covering (indusium) opening toward midrib