Baden-Württemberg - Lichens of Wales

hypochlorite produce corrosion and bleaching. It
is self evident that contact with the eyes is
hazardous. If this comes to pass, immediately
rinse the region of the eye with flowing water.
Reagents for the Determination of Lichens
The following reagents are required: 1.
Potassium hydroxide (Abbreviation: K), 2.
Calcium or sodium hypochlorite (C), 3.
Para-Phenylediamine (P), and 4. Iodine solution
(J). The regents keep longer when stored in
brown bottles and in the dark.
Potassium hydroxide: 2-4 g of potassium
hydroxide is dissolved in 20 cc of water. The
solution is infinitely stable. A false judgment of
the yellow reaction is sometimes possible, since
K makes the cortex transparent and the
underlying yellow-green algae layer gives a
misleading ± yellow-greenish coloring (see
remedy below: white filter paper).
Calcium Hypochlorite or Sodium
Hypochlorite Solution: Calcium hypochlorite is
obtained by dissolving chloride of lime
(bleaching powder) in water to saturation. Since
at best the solution is stable for one day and in
addition the precipitating chloride of lime may
cause annoying whitish flecks, it is better to use
sodium hypochlorite solution. They must
however be renewed from time to time, at best
every two months. Equally effective are chlorine
containing household cleansers (e.g. Clorox, also
only of finite stability). Verification of the
strength of the solution is produced by a simple
test with a test lichen (e.g. Hypocenomyce
scalaris). The reaction with C is often very
fleeting, therefore observe immediately!
In the case of the occasionally needed KC
reaction, first potassium hydroxide is used, then
C is brought to the same test site. As a rule, in
this way the C reaction is stronger and more
definite; the KC reaction is not however always
identical to the C reaction. In rare instances a
CK reaction is asked for (first C, then K!).
In the case of the test with KC on yellowish
species proceed in the following manner: lay a
piece of lichen on a slide and drop a little K over
it. After a little time take up the K with white
filter paper. Afterwards put a drop of C on the
paper and observe the color.
Para-Phenylendiamine solution: This reagent
is poisonous and leaves behind flecks on clothing
etc. (see above). Do the reaction with P when it
is stated in the species description. Avoid
however the reaction with P on principle, when it
is not essential for the determination.
The reagent (according to Steiner) is prepared
as follows: 1 g para-Phenylenediamine, 10 g
sodium sulfite and 1ml of a detergent in 100 ml
water. In this form it is stable for more than a
month.
An alternative to the health threatening para-
Phenylenediamine is offered by the Color
Developer 1 of Merck; it was formulated for the
color film developer process. According to the
formula: 10 g sodium sulfite, as (Na2SO3)
completely dissolved in distilled water + 3 g
N 4 ,N 4 -Diethyl-1,4-phenylene-diaminesulfate
(color developer) + 1 ml of a detergent, shake
until completely in solution. The solution is
stable for more than a month. The reactions with
this reagent appear merely somewhat later on and
the color is in the majority of cases pale (orange
instead of red).
Iodine Solution, for the study of the reactions of
the hymenium and of asci best in the form of
Lugol’s Solution (Merck): 0.5 g iodine, 1.5 g
potassium iodide, 100 ml distilled water. A
pretreatment with 10% potassium hydroxide is
advantageous, in making possible reliable
statements in studies of ascus structure. The
abbreviation for this is K/I.
Over sight of the most important lichen substances and their reactions
Explanation: Indicated color reaction only with a sufficient concentration of the lichen substance. Above all
in the case of P the reaction often alternates between yellow-orange and red. In parenthesis: in practice the
reaction (on the lichen) is often unclear or fails to appear, therefore to be carried out on isolated material.
Without indication: reaction the lichen negative, not proven on isolated material.
Reagent K C KC P
α-collatolic acid - - (red) -
Alectorialic acid yellow red red yellow
Alectoronic acid - - (red) -
Angardianic acid - - - -
Aotearon - - - -
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