Ferns reproduce by means of spores, a dust-like substance produced in capsules called sori on the underside of the fern leaf, or frond.
The silver fern or ponga is a national symbol of New Zealand and is named for the silver/white underside of its fronds
This fern (Cyathea dealbata) – ponga in Maori – is a species of tree fern only found in New Zealand.
UPDATE I have added an extra photo, two days later, showing the mass of spores released from the sori as seen in this main photo.
Thank you for the comments, stars and hearts for the ‘Twist of Lemon’ blip. The lemon was all that remained of a Classic Manhattan dry cocktail.