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CHAPTER 4 Pteridophytes and Conifers
Pteridophytes
Pteridophytes consist of a number of not very closely related plants some-
times referred to as ‘fern allies’, comprising clubmosses and horsetails, of the
families Lycopodiaceae and Equisetaceae, respectively; adder’s-tongue and
moonworts, of the unusual fern family Ophioglossaceae; as well as true ferns
of which members of the following families are included here: Osmundaceae,
Adiantaceae, Polypodiaceae, Dennstaedtiaceae, Aspleniaceae, Woodsiaceae,
Dryopteridaceae and Blechnaceae.
LYCOPODIACEAE
Huperzia selago (Linnaeus) Bernhardi ex Schrank & C. Martius
Lycopodium selago Linnaeus
fir clubmoss
northern temperate zone
Huperzia selago and Lycopodium clavatum are the only two of the seven spe-
cies in the family Lycopodiaceae native to the British Isles to have been cred-
ibly distinguished in the folk medicine records. Not only is H. selago the most
widely distributed, but a related Huperzia species long used in Chinese med-
icine has been found to produce a substance, huperzine A, with the power to
block a brain enzyme.Huperzia selago,known in both the Scottish Highlands
and Western Isles as garbhag an t’slèibhe and valued there, as in Scandinavia,
as a powerful emetic, was well known to be dangerous if taken in anything but
a small dose, being said to induce giddiness and convulsions^1 or (as reported
in Skye in 1768) causing a pregnant woman to abort.^2