- Cladonia sylvatica f. alpestris.
- Cladonia squamosa f. subsquamosa.
- Cladonia rangiformis f. foliosa.
- Cladonia cariosa and f. symphicarpa.
- Peltigera canina f. soreumatica.
- Solorina spongiosa.
- Heppia virescens.
- Lecanora crassa.
- Urceolaria scruposa f. argillacea.
- Verrucaria (Thrombium) epigaea.
- Lecidea decipiens.
- Dermatocarpon cinereum.
- Collema granulatum.
- Collema tenax.
- Leptogium byssinum.
It is interesting to note how many of these lichens specialized as to habitat are forms of species that grow in other situations.
b. On siliceous soil. Lichens are not generally denizens of cultivated soil; a few settle on clay or on sandbanks. Cladonia fimbriata and Cl. pyxidata grow frequently in such situations; others more or less confined to sandy or gravelly soil are, in the British Isles:
- Baeomyces roseus.
- Baeomyces rufus.
- Baeomyces placophyllus.
- Endocarpon spp.
- Gongylia viridis.
- Dermatocarpon lachneum
- Dermatocarpon hepaticum.
- Dermatocarpon cinereum.
These very generally grow in extended societies of one species only.
In his enumeration of soil-lichens Arnold[1146] gives 40 species that grow on siliceous soil, as against 57 on calcareous. Many of them occurred on both. Those around Munich on siliceous soil only were:
- Cladonia coccifera.
- Cladonia agariciformis.
- Secoliga (Gyalecta) bryophaga.
- Baeomyces rufus.
- Lecidea gelatinosa.
- Psorotichia lutophila.
Mayfield[1147] in his account of the Boulder Clay lichen flora of Suffolk found only four species that attained to full development on banks and hedgerows. These were: Collema pulposum, Cladonia pyxidata, Cl. furcata var. corymbosa and Peltigera polydactyla.
On bare heaths of gravelly soil in Epping Forest Paulson and Thompson[1148] describe an association of such lichens as: