Questions? AskAuckland

NZ Plants

Blechnum fluviatile - kiwakiwa, creek fern

Hard fern family: Blechnaceae

Blechnum fluviatile has a stout, erect stem with a drooping circle of sterile fronds surrounding a few erect fertile fronds equal to slightly longer in length than the sterile fronds.
Found in damp coastal and lowland forest throughout New Zealand.

Vegetative characteristics

Fertile frond and sporangia

Plant form: arching to horizontal fronds up to 750 mm in length.

Frond appearance: erect, leaflets very narrow and almost parallel to the frond axis (rachis)

Frond stalk, midrib: scales abundant throughout

Sporangium location: on lower frond surface

Frond shape: linear

Sporangium position: leaflet margin

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

Sporangium distribution: in groups (sori)

Frond surface: leathery

Sorus shape: in a continuous line either side of midrib

Leaflets: elliptic-oblong, rounded tip, margin toothed or smooth, attached by stalk or along base of leaflet

Sorus covering: linear covering (indusium) opening toward midrib