<jats:p> Lycopodium complanatum L. has yielded a total of eight alkaloids, six of which appear to be new. They are complanatine (L1) (C<jats:sub>18</jats:sub>H<jats:sub>31</jats:sub>ON); alkaloid L2 (C<jats:sub>18</jats:sub>H<jats:sub>29</jats:sub>O<jats:sub>2</jats:sub>N); alkaloid L3 (C<jats:sub>18</jats:sub>H<jats:sub>31</jats:sub>O<jats:sub>2</jats:sub>N); alkaloid L4 (C<jats:sub>16</jats:sub>H<jats:sub>27</jats:sub>N); alkaloid L5 (C<jats:sub>18</jats:sub>H<jats:sub>28</jats:sub>O<jats:sub>2</jats:sub>N<jats:sub>2</jats:sub>); obscurine (L6) (C<jats:sub>18</jats:sub>H<jats:sub>28</jats:sub>ON<jats:sub>2</jats:sub>); the known lycopodine (C<jats:sub>16</jats:sub>H<jats:sub>25</jats:sub>ON); and nicotine. It is pointed out that this is the first recorded occurrence of nicotine in a pteridophyte. The isolation of nicotine from Equisetum arvense L. is also recorded.