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Identification Worksheet

 

Lichen Outline and Vocabulary

Teacher Notes

I. Lichen: a symbiotic partnership of a fungus and an algae.

A. Thallus Anatomy: (Thallus: a leaf that never got off the ground)

1. Upper cortex: fungal protective covering-turns dark when dry to protect against the sun's damaging UV rays and turns transparent when wet to allow the sun's productive light through.

2. Algal Layer: algae makes sugars (ie. food) for the lichen.

3. Medulla: loosely packed fungal hyphae that enclose the algae. Maybe it holds water when wet? Transports the sugars around?

4. Lower cortex: tightly packed fungus that attaches to the surface

B. Thallus Growth Forms (Thalli: the thick body of the lichen)

1. Foliose: leaf-like (Catapyrenum and Peltula)

2. Crustose: flat with no lower cortex (Collema and Psora)

3. Fruticose: shrub-like or hair-like

C. Surface Shapes


1. Wrinkles: puckering of the surface that smooth out when wet.

2. Cephalodia: little black balls on the surface

D. Reproductive Structures: (Only the mycobiont goes through a sexual stage and it is how the lichen are categorized.)


1. Apothecia: cup shaped sometimes goblet shaped surface feature. Often different colored

2. Perithecium: little black bumps that reveal the buried organ.

II. Bryophytes: Mosses and Liverworts are true plants without vascularization.

    1. Liverworts Anatomy
      2.
      1. Capsule: reproductive cup at the top of the seta

      2. Seta: reproductive stalk raises the capsule heaven-ward and wind-ward

      3. Thallus: flat scale-like growth absorbs sunlight and shrinks up when dry to avoid more of that punishing sun.

      4. Rhizoid: root-like holds it down and gets a drink from the dirt

    2. Mosses' Anatomy
      3.

1. Capsule: reproductive cup: If you got it flaunt it?

2. Seta: reproductive stalk

3. Leaf: looks like a leaf

4. Protonema: runners

5. Rhizoid: fine root like soil holding structure

III. Blue-Green Algae (Cyanobacteria: eukaryotic photosynthetic bacteria)


A. Coccoid: small round individuals

B. Trichomes: filamentous chains

C. Heterocysts: enlarged cells that fix nitrogen

 

IV. Green Algae (Phycophyta: eukaryotic protozoans )

A. Coccoid: small round individuals

B. Trichomes: filamentous chains

C: Sexual cells:

1. Oogamy: different sized sex cells

2. Spores: small asexual cells

 (Eukaryotic means that each cell has visible stuff floating around inside it)