40 Fun Facts About Ferns

The silver fern, a tree fern whose fronds are white underneath, is a national symbol of which country?

New Zealand's Māori stories tell of hunters laying the fronds pale side up, so the undersides caught the moonlight and marked the way home.

Old European folklore held that carrying the dust-like 'seed' of a fern gave a person which power?

Invisibility made a kind of sense: nobody could find a fern's seed, so the seed had to be unseen and able to pass that on. Thieves in Shakespeare's Henry IV, Part 1 joke about it.

Ferns reproduce with spores instead of seeds, a habit they share with which other group of plants?

Mosses also spread by spores, but ferns are vascular plants, with internal veins that carry water and let some of them grow as tall as trees.

The resurrection fern, which carpets oak limbs in the American South, is named for surviving what?

Long droughts curl it into a grey-brown husk that has lost up to 97 percent of its water, yet a day or two after rain it is green again.

For more than a thousand years, Asian farmers have floated the tiny fern Azolla on flooded fields of which crop?

Rice gets free fertilizer from Azolla, which shelters bacteria in its leaves that pull nitrogen straight out of the air.

Which ancient tree is nicknamed the maidenhair tree because its leaves resemble a maidenhair fern's?

Ginkgo leaves fan out like the leaflets of a maidenhair fern, but the tree is a seed plant, the last living species of an order 290 million years old.

Which fern, a toxic weed of moors and hillsides, grows on every continent except Antarctica?

Bracken's name probably comes from an old Scandinavian word for fern, and its fronds carry a carcinogen that can pass into the milk of cows that graze on it.

The coiled tip of a young fern frond, a fiddlehead, is also called a crozier after whose hooked staff?

A bishop's crozier curls over at the top just like the frond, while the name fiddlehead comes from the scroll at the end of a violin.

Which British sandwich biscuit is still stamped with a swirling fern pattern from a 19th-century craze?

Custard cream biscuits wear baroque fern fronds whoever bakes them, a design that outlived the fashion for ferns by more than a century.

Wardian cases, glass boxes built to keep ferns alive in smoggy London, later took which crop from China to India?

Tea plants, about 20,000 of them, were smuggled out of Shanghai in the 1840s by Robert Fortune in the cases, which were the forerunners of the terrarium.

Slavic and Baltic legend says a magical fern flower blooms for a single night on the eve of which festival?

Midsummer is the night to hunt for it: the bloom is said to bring riches to its finder, though evil spirits guard it. Real ferns never flower at all.

Tree ferns can stand 20 metres tall, yet their trunks completely lack which tissue found in true trees?

Wood is absent: the trunk is an upright stem strengthened by a thick, interlocking mat of its own tiny roots.

Which plants, gritty with silica and once used to scour cooking pots, are now classified among the ferns?

Horsetails look nothing like ferns, with hollow, jointed stems and no fronds, but genetic studies placed them inside the fern family tree.

A 'fern spike' in the fossil record marks ferns briefly taking over the land after which kind of event?

A mass extinction leaves bare ground that wind-blown fern spores reach first; the best-known spike follows the impact that ended the age of dinosaurs.

A fern spore first grows into a tiny separate plant called a prothallus, which typically has what shape?

A heart just a few millimetres wide is what sprouts from a spore, and it lives on its own before a familiar leafy fern grows out of it.

Why do ferns, unlike seed plants, need a film of water on the ground in order to reproduce?

Their sperm must swim: each one has whip-like tails and crosses a film of rain or dew to reach an egg on the tiny plant that grew from a spore.

The fork fern Tmesipteris oblanceolata was reported in 2024 to have the largest known what of any organism?

Genome size is its record: about 160 billion base pairs of DNA, more than 50 times the human total, packed into a plant under a foot long.

Which houseplant, often sold alongside ferns, is really a flowering plant that produces berries and seeds?

Asparagus fern belongs to the asparagus family and comes from southern Africa: its feathery 'leaves' are really tiny modified stems, and its berries are toxic to pets.

The Chinese brake fern is planted to clean polluted soil because it soaks up huge amounts of which poison?

Arsenic is drawn out of the ground and held inside the plant in huge amounts, which turns a pretty garden fern into a tool for phytoremediation, cleaning soil with living plants.

Vast blooms of the floating fern Azolla may have tipped Earth toward its ice ages after covering which ocean?

The Arctic was then a warm, almost enclosed sea; ferns that died and sank over some 800,000 years are thought to have buried enough carbon to help chill the planet.

The Barnsley fern, a computer-drawn shape modelled on the black spleenwort, is a well-known what in mathematics?

A fractal repeats its own shape at every scale, and this one grows a lifelike frond from just four simple transformations applied over and over.

Which restaurant chain began as one of the first 'fern bars', the plant-filled singles spots of 1970s America?

TGI Fridays opened on Manhattan's Upper East Side, home to many young single adults, and fern bars went on to pair hanging greenery with Tiffany-style lamps.

Fiddleheads sold as a spring vegetable in northeastern North America come from a fern named after which bird?

Ostrich ferns have tall fronds shaped like the bird's plumes, and their fiddleheads are a delicacy that should be cooked, never eaten raw.

The water fern Marsilea looks so unlike a fern that it is easily mistaken for which lucky plant?

Clover it is not, though every leaf has four lobes: one Australian species, nardoo, was ground into flour by the explorers Burke and Wills, whose deaths are blamed partly on preparing it wrongly.

The adder's-tongue fern Ophioglossum reticulatum holds the record among plants for the most what in each cell?

Chromosomes run to many hundreds in each of its cells, against a human's 46, because the plant has copied its whole set several times over.

Staghorn ferns, named for their antler-shaped fronds, naturally grow anchored to what?

Tree trunks hold them high in the forest: shield-shaped fronds clamp to the bark and protect the roots, while the 'antlers' hang free and carry the spores.

The Christmas fern of eastern North America is named for what its fronds do in late December?

Stay green is the whole trick: the plant is an evergreen, so its fronds are often still fresh at Christmas when the woods around them are bare.

Swamp forests of ferns and their giant relatives, buried around 300 million years ago, slowly became what?

Coal is the squeezed remains of those forests, and their era's name says so: Carboniferous means coal-bearing in Latin.

The sensitive fern of North American wetlands is named because its fronds die at the first touch of what?

Frost kills the fronds almost overnight in autumn, while a brush from a hand does nothing, unlike the folding leaves of the mimosa called the sensitive plant.

North America's walking fern 'walks' across damp rocks by doing what with its long, tapering fronds?

Rooting at the tips starts a new plantlet wherever a frond arches over and touches down, so a colony creeps forward one frond-length at a time.

Climbing ferns of the genus Lygodium twine up trees like vines, yet each 'vine' is really a single what?

Leaf is the surprise: each frond keeps unrolling at its tip with no fixed end, and in some species it grows 12 metres long.

The male fern, a common woodland fern of Europe, was long used in medicine to expel which parasites?

Tapeworms were its target so reliably that old writers called the plant worm fern, and its Finnish name still recalls the cure.

Peoples of the Pacific Northwest chewed the sweet rhizome of a fern named after which flavoring?

Licorice fern gets the taste from its creeping rhizome alone, and it is no relation of the plant that flavors the candy.

In the novel Where the Red Fern Grows, the red fern of the title springs up between the graves of what?

Two hunting dogs, the Redbone Coonhounds Old Dan and Little Ann, lie there, and young Billy finds the fern on his last day in the Ozarks in Wilson Rawls's 1961 story.

The town of Pierson, self-styled 'Fern Capital of the World' for its florist greenery, is in which US state?

Florida's Pierson lives largely on fern growing, and its cut fronds are exported worldwide to fill out bouquets and floral arrangements.

Giant salvinia, a floating fern from Brazil that smothers lakes worldwide, is best controlled by which insect?

A weevil from the fern's South American home eats its buds while its larvae chew the roots; a 1980 release in Queensland had cut one lake's infestation to a few patches by mid-1981.

The English word 'fern' shares an ancient root with a Sanskrit word that means what?

Feather is the likely picture behind the name: Old English fearn and German Farn are cousins of the Sanskrit parna, and a fern frond does look like a plume.

The floating fern Azolla is nicknamed for an old belief that its dense mats stop which insects from laying eggs?

Mosquitoes can in fact get through the mat, so the nickname rests on a myth, though the fern does cut the survival of their larvae.

Fern Grotto, a lava-rock cave draped in ferns and known as a romantic wedding spot, is on which Hawaiian island?

Kauai's grotto sits on the Wailua River and is reached by boat; Hurricane Iniki nearly destroyed it in 1992.

Gosari, young fern shoots soaked and then stir-fried, are a typical ingredient of which Korean dish?

Bibimbap gets an earthy chew from gosari, and Korean cooks traditionally soak the shoots in water and ash to draw out their toxins before cooking.