Keys to the macrolichens and checklist of the lichens and ...

15b. Cyphellae and pseudocyphellae absent from lower surface, but bald patches may
be present amongst the tomentum.......................................................................... 17
16a. Cyphellae present with distinct raised margins, thallus smelling of fish when wet.
........................................................................................................................... Sticta
16b. Pseudocyphellae present without distinct raised margins, thallus not smelling of
fish when wet ............................................................................... Pseudocyphellaria
17a. Lower surface naked or sparingly tomentose (but tomentose in two extinct
species), apothecia (if present) on lower surface of lobe ends ................. Nephroma
17b. Lower surface tomentose, apothecia (if present) on upper surface of thallus or
lobe ends ................................................................................................................ 18
18a. Lower surface with a ± well-developed coarse network of white or brown veins;
apothecia (if present) on short marginal projections................................... Peltigera
18b. Lower surface without veins, but with bald patches amongst the tomentum;
apothecia (if present) laminal........................................................................ Lobaria
19a. Thallus with spongiostratum (dense sponge-like cushions on lower surface)....... 20
19b. Thallus without spongiostratum............................................................................. 21
20a. Upper surface yellowish, with usnic acid .........................Pannoparmelia angustata
20b. Upper surface grey, without usnic acid............................................................. Anzia
21a. Thallus lobes inflated, hollow in section, lower surface without rhizines............. 22
21b. Thallus lobes solid in section, flat or convex......................................................... 23
22a. Thallus without perforations on the upper surface ................................Hypogymnia
22b. Thallus with perforations on the upper or lower surface ........................ Menegazzia
23a. Lobes with tomentum on lower surface, with or without lower cortex................. 24
23b. Lobes with distinct lower cortex, tomentum absent .............................................. 28
24a. Thallus lobes rounded, with a single urceolate apothecia ± immersed in the centre
of the thallus or if absent lower surface orange and without distinct veins.
........................................................................................................Solorina simensis
24b. Thallus lobes spreading, or if rounded then with distinct raised veins; apothecia if
present on margins of the thallus ........................................................................... 25
25a. Lobes without a lower cortex; rhizines often conspicuous to the margin... Peltigera
25b. Lobes with a distinct lower cortex; rhizines absent from the margin of the lower
surface.................................................................................................................... 26
26a. Cyphellae and pseudocyphellae absent on lower surface............................. Lobaria
26b. Cyphellae or pseudocyphellae present on lower surface ....................................... 27
27a. Cyphellae white, with distinct raised margins present on lower surface.......... Sticta
27b. Pseudocyphellae present as punctiform or effigurate breaks in the lower cortex.
...................................................................................................... Pseudocyphellaria