Estimating the population size of the endemic lichens Anzia centrifuga (Parmeliaceae) and Ramalina species (Ramalinaceae) on Porto Santo (Madeira archipelago)

1. Sparrius, L.B.
2. Aptroot, A.
3. Sipman, H.J.M.
4. Pérez-Vargas, I.
5. Matos, P.
6. Gerlach, A.
7. Vervoort, M.