WHAT IS A LICHEN?

 

     A LICHEN IS AN ORGANISM

     RESULTING FROM A SYMBIOTIC      RELATIONSHIP BETWEEN TWO

     ORGANISMS FROM TWO DIFFERENT

     KINGDOMS

 

     ALGAE - KINGDOM PROTISTA

 

     FUNGI - KINGDOM FUNGI

 

     SYMBIOSIS - “LIVING TOGETHER”

 

          TYPE - MUTUALISM

 

          BOTH ORGANISMS BENEFIT FROM

          THE RELATIONSHIP

 

          HOW?

 

          ALGAE PHOTOSYNTHESIZE TO

          PRODUCE FOOD

 

 

          FUNGAL HYPHAE PROTECT

          ALGAE FROM DRYING OUT

 

ALGAE + FUNGAL HYPHAE = THALLUS

 

THALLUS DOES NOT RESEMBLE EITHER THE ALGAE OR THE FUNGUS

 

THE COMPONENTS CAN BE SEPARATED INTO INDEPENDENT CULTURES BUT CANNOT BE RECOMBINED TO FORM THE ORIGINAL LICHEN

 

LICHENS ARE CLASSIFIED AS CRYPTOGAMS

 

     CRYPTOGAMS = LICHENS, MOSSES

     AND FUNGI

 

LICHENS DON’T HAVE LEAVES

LICHENS CAN SURVIVE IN A DRIED STATE

 

 

 

DIVERSITY IN LICHENS

 

     GENERAL:

 

     1.     RANGE IN SIZE FROM 1 CM TO

          30 CM

 

     2.     ROUND IN OUTLINE

 

     3.     GROWTH FORM

 

          a.     FOLIOSE

 

          b.     FRUITICOSE

 

          c.     CRUSTOSE

 

     4.     COLOR (DETERMINED AFTER THE

          LICHEN IS AIR DRIED AND IN             BRIGHT LIGHT)

 

          a.     MINERAL OR GREENISH GRAY

 

          b.     GREENISH YELLOW

 

          c.     SULPHUR OR LEMON-YELLOW

 

          d.     ORANGE

 

          e.     BROWN

 

          f.     TAN, STRAW, BUFF

 

          g.     SLATE BLUISH OR LEAD

               (GELATINOUS)

 

GROWTH FORMS

 

FOLIOSE

 

     1.     FLATTENED AND PROSTRATE

 

     2.     TOP AND BOTTOM SURFACES

          DIFFERING IN COLOR OR                SURFACE FEATURES

 

     3.     THALLUS EXPANDS OUTWARD

          FROM THE CENTER

 

     4.     CAN BE DIVIDED INTO SIZE                CLASSES BECAUSE THEY HAVE

          A DEFINITE MAXIMUM

 

          a.     SMALL: 1-2 CM

 

          b.     MEDIUM: 3-12 CM

 

          c.     LARGE: 13-30 CM

 

     5.     THALLUS ATTACHED BY                       RHIZINES OVER MOST OR ALL

          OF THE LOWER SURFACE

 

     6.     TIGHTNESS OF ATTACHMENT

          IMPORTANT

 

          a.     APPRESSED OR CLOSELY                       ADNATE - CANNOT BE

               EASILY REMOVED WITHOUT

               SOME DAMAGE

 

         

 

 

          b.     ADNATE, LOOSELY ADNATE,

               LOOSELY ATTACHED - RE-

               MOVED WITH A KNIFE OR BY             HAND

 

     7.     THALLUS DIVIDED INTO

          BRANCHES CALLED LOBES

 

          a.     NARROW:  0.1 - 2 mm WIDE

 

          b.     BROAD:   3 - 20 mm WIDE

 

     8.     THALLUS MARGINS VARIOUS

 

          a.     SMOOTH

 

          b.     INDENTED

 

               -     CRENATE

               -     DENTATE

               -     DISSECTED

               -     CILIATE (0.5 TO 6 mm)

 

 

 

     9.     UPPER SURFACE TEXTURE

          VARIOUS

 

          a.     CONTINUOUS, NO BREAKS

 

          b.     CRACKED

 

          c.     WHITE-SPOTTED OR WITH

               WHITE MARKINGS

 

               -     WHITE PORES ARE

                    PSEUDOCYPHELLAE

 

               -     WHITE HOARY (HAIRY) =

                    PRUINA

 

          d.     TINY WARTY THALLI (.5

               TO 1 mm IN DIAMETER) =

               CEPHALODIA

 

     10.LOWER SURFACE CHARACTERS

 

          a.     COLOR - JET BLACK TO                     BUFF (NOT WHITE)

 

               EDGES MAY BE LIGHTER       

 

          b.     MAY HAVE VEINS

 

          c.     CORTEX MAY BE:

 

               -     LACKING (MEDULLA                          SEEN)

 

               -     COVERED WITH RHIZINES

                    OR TOMENTUM

 

               RHIZINES ARE COMPACTED

               STRANDS OF FUNGAL HYPHAE