fearn

Old English fearn is one of the oldest plant words in the language, traceable to Proto-Germanic *farną and possibly to Proto-Indo-European *pornóm, meaning 'feather' or 'wing.' The same root may give us the word 'fir' (as in fir tree). The connection is visual: fern fronds resemble feathers. Sanskrit parṇá (feather, leaf) is a cognate. The word has been in continuous use for well over a thousand years, and the plant it names has been growing for roughly 360 million.

Ferns dominated the earth's forests during the Carboniferous period, 360 to 300 million years ago, when tree ferns grew up to 20 meters tall. The coal deposits that powered the Industrial Revolution are largely compressed fern forests. When you burn coal, you are burning 300-million-year-old ferns. The plants that powered the steam engine were older than the dinosaurs, the flowers, and the continents as we know them — during the Carboniferous, all land was one supercontinent, Pangaea.

Medieval Europeans believed that fern seeds, gathered at midnight on St. John's Eve (June 23), would make the bearer invisible. Shakespeare references this in Henry IV, Part 1: 'We have the receipt of fern-seed, we walk invisible.' The belief rested on a logical error that was also a biological mystery: ferns produce no visible seeds, so their method of reproduction was unknown. The discovery that ferns reproduce through spores — tiny, dust-like particles released from the underside of fronds — was not confirmed until the nineteenth century.

The 'fiddlehead' — the tightly coiled emerging frond of a young fern — is eaten as a seasonal vegetable in New England, eastern Canada, and parts of Japan and Korea. The Māori of New Zealand use the silver fern (Cyathea dealbata) as a national symbol; the frond's spiral shape, called koru, represents new life and growth. The oldest surviving plant group on earth is still being eaten, worn as a symbol, and misunderstood.