Information on Adder's Tongue

Common Name: Adder's Tongue
Scientific Name: Ophioglossum vulgatum
Irish Name: Lus na teanga
Family Group: Ophioglossaceae
Distribution: View Map (Courtesy of the BSBI)
Flowering Period


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Adder's Tongue is not easily confused with other wild plants on this web site.


This is a very short, perennial plant which is extremely difficult to spot – until you see the first one – after that it's easy!  It only reaches about 10cm high, has one upright, oval, green leaf which partly surrounds an upright spike.  The spores, by which the plant reproduces, are contained in this spike which itself grows taller than the solitary leaf. The photograph is of a young Adder's Tongue, the spike still smaller than the leaf.  It is quite abundant in parts of the Burren and frequently found throughout the country, best looked for from May to July, is a native plant and belongs to the family Ophioglossaceae. 

I first recorded (and photographed) this plant growing in the Raven Nature Reserve, Co Wexford in May, 2008.  Christopher Wilson of the Wexford Naturalists Field Club had kindly told me where I might find it and he was absolutely right.   

If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre

Adder's Tongue
Adder's Tongue

Ophioglossum vulgatum
Buried among grasses, amid
Plantains, which I resemble,
You may find me, if you
Look hard, and are not fooled:

A fern whose frond does not unfold
Like filigree, but like the leaf
Of a flowering plant; armed
With a spike that is snake-like
To those unfamiliar
With the forked tongues of adders.

Notwithstanding, by sympathy I assuage
The serpent's poison, and make a salve
For cows' udders when inflamed,
Unblocking teats, mastitis clogged.

I am indicated, too,
For disorders of the tongue,
As a drink for wounds,
A balm for bruises,
A lotion for the weeping eye.

Follow the serpents to find me;
She who picks me, snakes pursue.

Ophioglossum vulgatum : Giles Watson : 2004*
See: http://delta-intkey.com/britht/www/poems.htm
and follow link to Poems on Flowering Plants