Chapter V: Physiology (3)

Among “rusty” lichens are the British forms, _Lecanora lacustris_, the thallus of which is normally white, though generally more or less tinged with iron; it inhabits rocks liable to inundation. _L. Dicksonii_ owes its ferruginous colour to the same influences. _Lecidea contigua_ var. _flavicunda_ and _L. confluens_ f. _oxydata_ are rusty conditions of whitish-grey lichens.

Nilson[895] found rusty lichens occurring frequently in the Sarak-Gebirge, more especially on glacier moraines where they were liable, even when uncovered by snow, to be flooded by water from the higher reaches. It is the thallus that is affected by the iron, rarely if ever are apothecia altered in colour.

BACHMANN’S PIGMENT REACTIONS

----------------+---------------+-------------+-------------+----------+
Name of Pigment | Colour | KOH | NH₃ | Ba(OH)₂ |
or Lichen | | | | |
----------------+---------------+-------------+-------------+----------+
Lecidea-green | green | | | |
| | | | |
Aspicilia-green | green | | | |
| | | | |
Bacidia-green | green | | | |
| | | | |
Thalloidima- | green | violet | | |
green | | | | |
| | | | |
Rhizoid-green | bluish-green | olive-green | | |
| | to brown | | |
| | | | |
_Biatora | blue | dissolves | | |
atrofusca_ | | with | | |
| |greenish-blue| | |
| | colour | | |
| | | | |
_Phialopsis | brick-red | | dirty | |
rubra_ | | | purple-red | |
| | | | |
Lecanora-red | purple-red | | deep violet | |
| | | | |
_Sagedia | bluish-red | blue |greenish-blue| blue |
declivum_ | | (green) | then | |
| | | grey-black | |
| | | | |
_Verrucaria | rose-red | dark-green | |dark-green|
Hoffmanni_ f. | | | | |
_purpurascens_ | | | | |
| | | | |
_Bacidia |yellowish-brown| violet | violet | violet |
fuscorubella_ | | | | |
| | | | |
_Sphaeromphale | leather-brown | deep | | |
clopismoides_ | | olive-green | | |
| | | | |
_Segestria | yellow-brown | rose-red | | |
lectissima_— | | | | |
perithecia | | | | |
| | | | |
_Segestria | brown and | | | |
lectissima_— | colourless | | | |
entire tissue | | | | |
| | | | |
_Parmelia | leather-brown | | | |
glomellifera_ | | | | |
| | | | |
Parmelia-brown | yellow to |dirty- to | | |
|blackish-brown |olive-brown | | |
----------------+---------------+-------------+-------------+----------+

----------------+---------------+-------------+-------------------------
Name of Pigment | HNO₃ | H₂SO₄ | Special
or Lichen | | | Reactions
----------------+---------------+-------------+-------------------------
Lecidea-green | copper or | | KOH then HCl: blue
| brick-red | |
| | |
Aspicilia-green | | | HNO₃: brighter green
| | |
Bacidia-green | violet | violet | HCl: violet
| | |
Thalloidima- | indistinctly | | HCl: indistinctly
green | purple-red | | purple-red
| | |
| | |
Rhizoid-green | olive-green | |
| | |
_Biatora | violet, then | dissolves | H₂O insoluble
atrofusca_ | yellow, then | |
| decolourized | |
| | |
_Phialopsis | violet | |
rubra_ | | |
| | |
Lecanora-red | | |
| | |
_Sagedia | | |
declivum_ | | |
| | |
_Verrucaria | | | KOH then HNO₃ then
Hoffmanni_ f. | | | H₂SO₄: violet
_purpurascens_ | | | crystals
| | |
_Bacidia | | |
fuscorubella_ | | |
| | |
_Sphaeromphale | | | KOH, then H₂SO₄,
clopismoides_ | | | then HNO₃: blackish
| | |
_Segestria | bright yellow | | dilute H₂SO₄:
lectissima_— | | | bright yellow
perithecia | | |
| | |
_Segestria | | | Strong H₂SO₄: deep
lectissima_— | | | violet, then grey
entire tissue | | |
| | |
_Parmelia | blue, | | CaCl₂O₂: blue, then
glomellifera_ | then violet, | | grey; finally
| at last grey | | decolourized
| | |
Parmelia-brown | bright | |
| red-brown | |
----------------+---------------+-------------+-------------------------