"Likable Lichens"


Subject: Lichen Connections

Grade Levels: MS/9/10



Dorothy Smullen

North Plainfield High School

Wilson Avenue

North Plainfield, NJ 07060

School Telephone: (908) 769-6000

Home Telephone: (908) 647-5740


February 20, 2000



A Classroom Teaching Module Developed as a Result of

Participation in the

NJ BISEC Microbiology Summer Residential Institute (MSRI)

For Middle School Science/High School Biology Teachers


Cook College of Rutgers University

New Brunswick, NJ

July 18-23, 1999


1999 MSRI Funding Provided by:

The Foundation for Microbiology

Johnson and Johnson





Title Page Page 1

Table of Contents Page 2

Origin of Project / Unit Idea Page 3

Abstract Page 4

Project Directions / Unit Plan Page 5 to Page 14

Project Description


Grade / Course / Student Population

Interdisciplinary Connections /

Instructional & Assessment


Student Performance Standards

Learning Activities

Materials / Resources / Safety

About the Author

Publicity Information. Page 15 to Page 16

Student Copy of Module

and Answer Sheet Page 1 to Page 7




Upon receiving our notebooks for MSRI 1999 I was very excited to see that we would be going on a woodland walk to collect fungi specimens and lichens (along with mud for a Wingradsky Column-whatever that was?).

I knew we would probably be studying bacteria, mold fungi and possibly protists but this was a chance to explore long-overlooked lichens. Yes, they have a macroscopic thallus, but one needs to use the microscope to view their component parts.

Some species are extremely common but hardly noticed in our surroundings. This was a chance for me to explore their world with applications to all sciences. In addition, wonderful websites about lichens were already copied in our notebooks. Later in the summer, I was going to go to Norway and Maine and get a chance to look at many different species of lichens in the coniferous forest biome.

Lichens and Dorothy's Module......Perfect Together!




Title of Module: Likable Lichens

Project Description: This project was designed to introduce the subject of lichens to students; to give students more of an appreciation of lichens and to have students discover the components of lichens and realize their connections to the environment and microbiology.


Environmental Science - unit on succession;

Biology - unit on Fungi

Grade/Course/ Student Pop.


2-3 periods/ heterogeneous

Interdisciplinary Connections/

Instructional & Assessment



Use of Demonstration/ Hands-on

Discovery/ Cooperative Learning

Assessment: graded answer sheet

and drawing

Student Performance Standards:

NJ Core Curriculum

5.1, 5.2, 5.3, 5.6, 5.7, 5.12

Learning Activities

Motivation and Cultural connections

What are lichens?-use of microscopes

Env. Sci connections -pollution

Lichen Groups - classifying

Materials/ Resources / Safety

Materials: lichen use samples,

microscopes and lenses

single edge razor blades

display specimens

foliose lichens to examine

field guides and articles


Lichen Tidbits



G.B. Map

Dye Bath Directions

Mud column Directions


About the Author: BA and MA from Brooklyn College; Major in Biology; Teaching for 16 years; Subjects taught - Env. Sci., Biology, Life Science, Physical Sci., Earth Sci.

Dorothy Smullen developed this module over several months in 1999 as a participant in the NJ BISEC Microbiology Summer Residential Institute.




A. Project Description:

This project was designed to introduce the subject of lichens to students; to give students more of an appreciation of lichens other than one picture in the textbook; and to have students discover the components of lichens and realize their connections to the environment and microbiology.


B. Background:

Students taking 9th grade Environmental Science have a unit on Succession in which this module could be used. Students taking Biology in 9th or 10th grade or middle school Life Science could include this module in their overview of biodiversity - Kingdom Fungi.

Students will gain an understanding of an organism with interacting components; conduct observations; begin connections to other science units; and observe how cultures and organisms have benefited from lichens.


C. Grade/Course/Student Population

Middle School, 9th or 10th grade. Module was designed for Env. Sci. at 9th grade level - heterogeneous grouping for 2-3 class periods. Module may be adapted to Life Sci. or Biology. Parts of the module can be generated by discussion with the entire class, at the individual level or in small groups.


D. Interdisciplinary Connections/ Instructional & Assessment Methodology

E. Student Performance Standards:

NJ Core Curriculum Content Standards - 5.1, 5.2, 5.3, 5.6, 5.7, 5.12


F. Learning Activities of the Module


Teacher Instructions:




Teacher should assemble some of the items on the chart and creatively display them on the lab desk.. Ask the question "What do all of these items have in common?" Entertain some answers and then hand out the student packet of the module. Discuss the objects using some of the information below:

Purple yarn or fabric: lichens have been used for centuries for purple dye - you might discuss "royal purple" which was also produced by the Medit. snail Murex. Check the teacher resource section for a purple dye preparation activity.

Reindeer toy or picture: a large component of food for reindeer in the tundra biome is actually a lichen called reindeer "moss".

(Chance to bring out the problem of common names.)

Perfume or fragrant soap: some lichens (Evernia) produce a binder compound for perfumes. It is oily with a "mossy" odor.

Litmus: dyes from certain lichens are used as acid/base indicators

Model train or tracks: certain lichens are painted green and used as shrubs or trees in model train layouts.

Piece of Harris Tweed or look-alike: some hand-woven wool fabrics from a Scottish island are dyed with brown lichen dyes.

Antibiotic creams: Usnic acid from certain lichens is used in some hand creams.

Students should fill in their charts and Part I of the answer sheet.






A. Instruct students in use of hand lenses or dissecting scopes as well as the care needed in using a single-edge razor blade. Students should be able to see a white layer under the grayish-green surface, and be able to describe this on their answer sheet.

B. Teacher should familiarize students with parts, handling, use and care of the compound microscope if this is not already known. Instruct students on making a wet-mount. Only a minute amount of the surface of the lichen is needed (like a tiny pinch of "powder"). The mycobiont cells will be like fungal hyphae -long and narrow. The photobiont cells are larger green spheres. (HP) Have students search the slide. They should not draw everything they see. Students should carefully make outline drawings of the two cell types in proportion by size and label each. Drawings could be graded on neatness, full use of page, correct proportion, labelling and cell descriptions. Students may work indivually sharing microscopes or in teams of two for drawing.



Students should read the introduction. Explain that the key below the map in the packet refers to different zones. Then the zones are described as to the abundance or number of species in each. Students may work in teams to fill in the answer sheet matching question. For the three other questions, students must use a reference map of Great Britain. See the resource section for such a map which you may want to post in your classroom.




G. Materials / Resources / Safety:


lichen use samples such as litmus vials, purple cloth

compound microscopes and lenses

single-edge razor blades HANDLE WITH CARE

display specimens and foliose lichens for examination

Great Britain map

field guides and articles on lichens

Resources Included:

Lichen Tidbits



Great Britain Economic Map

Directions for Purple Dye Bath -"Passion for Purple"

"Stuck in the Mud Microbes"






Teacher Resource: REFERENCES


Casselman, K.L., Craft of the Dyer - Dover Publications, NY. 1993

Corbridge, J. & Weber, W., A Rocky Mountain Lichen Primer

University Press of Colorado. 1998.

Dobson, Frank, Lichens: An Illustrated Guide - Richard Pub. Co. LTD.

Great Britain. 1981.

Hale, Mason, How to Know the Lichens - McGraw-Hill. 1979

Kaufman, P., Plants, Their Biology and Importance - Harper and Row, N.Y. 1989

Margulis, L., and Schwartz. Five Kingdoms - Freeman and Co. 1998.

Philips, Roger, Grasses, Ferns, Mosses and Lichens of G. B. - Pan Books. 1980

Reader's Digest, North American Wildlife. Pleasantville, N.Y. 1982.

Sharnoff, S., Lichens - More than Meets the Eye - National Geographic

191:2. Feb. 1997. p.58-71.



(Insert attachment A here)


Teacher Resource



Directions for Purple Dye Bath from Lichens

If you have access to umbilicate lichens (common on rocks in New England states), you might collect a few (no more than 10% of the population and mostly from loose specimens on the ground) and try this dye preparation technique. Crumble the dry specimens and place (1/3 fill) in wide mouth jar with tight fitting lid. Fill jar to 1/4 with non-sudsing household ammonia. Shake the contents to wet pieces. In a few days (2-3) add warm water near to the top - about 3X as much water as ammonia. Seal tightly and place in an obvious location so that you remember to shake it everyday for one to two months. Watch the purple dye color develop over time. The longer you wait, the deeper the color.


Consult craft books for natural dying techniques of wool or silk if you wish to use your dye bath.

Experiment with adding acid to a sample of your dye bath to see what color changes occur.



Goal: To see evidence of different bacteria without use of the microscope

Materials: wetland mud (salt marsh or stream bank)

a one L plastic soda bottle (top cut off)

1 teasp. CaSO

1 teasp. CaCO

1/2 page shredded newspaper

distilled water

Procedure: Remove any rocks and sticks from mud slurry (moisten with distilled water or stream water if necessary).

  1. Add mixed newspaper shreds, CaSO and CaCO to bottom of tube
  2. Cover with a little wet mud and tap down to remove all the air
  3. Continue to add mud til 3/4 of tube is filled
  4. Tap down to remove air
  5. Let material settle
  6. If liquid up to 2 cm is not covering the mud then add some distilled water to bring the liquid to 2 cm above the mud
  7. Place near light source to get side light but not heat
  8. Seal top with plastic wrap and stong rubber band
  9. Do not let column dry out
  10. Develop for a month or more and note colors of colonies


  1. Check column for development and growth of colored colonies
  2. Note time of development
  3. Check diagram for type of bacteria.



References: Eveleigh, D. and Davis, D. Whimsical Wrinkles with

Winogradsky's Wonder. SGM Quarterly. Nov. 1996. 106-7.

Schipper, A. and Schipper, L. Mud Microbiology.

The Science Teacher. 66 #5. May 1999 p. 26-28.


H. About the Author:


Dorothy Smullen has a BA and MA from Brooklyn College with a major in Biology. She has been teaching for 16 years in NJ. Before that she was director of the Reeves-Reed Arboretum in Summit for 5 years.

She received a National Science Foundation Fellowship in 1968 for a summer seminar in Tropical Botany. In 1987 she received the Eximia Award for contributions to amateur mycology from the Northeast Mycological Foray.

Dorothy has been a presenter for the NJ Science Teachers Convention in 1991, 1992 and 1999. In 1992, she attended NJ BISEC Residential Summer Institute (RSI) for Middle School Teachers. She also was accepted to the year long 1993-1994 NJ BISEC Clinical Institute at Morristown Memorial Hospital.

Memberships include the New Jersey Mycological Association (25 years), New Jersey Audubon, Nature Conservancy and the Long Hill First Aid Squad.


Likable Lichens


Part I LICHEN USES -- Observe from Teacher's Demonstration


Use of Lichen

Purple fabric or yarn


Reindeer (toy)


Perfume or soap


Litmus vials (red and blue)


Model train or tracks


Piece of Harris tweed


Antibiotic cream



Listen to your teacher and fill in the above chart. Then answer the questions in part I of the answer page.




Lichens have long been known as pioneer species because of their role in primary succession and soil formation on bare rock. The reason that they can colonize this surface is that each lichen is actually a partnership of two kinds of organisms. Close associations in biology are called symbiotic relationships (symbiosis). If both organisms benefit the arrangement is called mutualism. If one of the organisms is harmed it is called parasitism. Most resources consider a lichen as mutualistic but some consider it to be controlled parasitism.


The lichen is composed of a structure called a thallus which includes:

a fungus: called the mycobiont and an alga: the photobiont - may be a green alga or a blue-green alga now called a cyanobacterium


  1. The photobiont (alga) provides carbohydrates through photosynthesis, proteins and vitamins for itself and the fungus.
  2. The mycobiont (fungus) provides protection, support, water storage and minerals (absorbed from substrate). Water storage can prevent desiccation.

Most bacteria, algae and fungi are considered microbes because their study depends on the use of the microscope. Microbiologists recognize a classification system that divides living things into three domains rather than five kingdoms. (See figure A.) Answer the questions in Part II on your answer sheet.


DISCOVERY TIME: Microscope Activity

Follow instructions from your teacher in using the microscope. You will need the following: Scalpel or single edge razor blade

10x hand lens or dissecting scope

glass slides and cover slips

dropping bottle of 3% KOH

lichen specimen


Step 1. Obtain a dry lichen thallus (foliose type such as Peltigera or Parmelia sp.) from your teacher. Make a diagonal slice through the thallus. Examine the cut surface with a hand lens or a dissecting scope. Describe your observations of the cut surface on the answer sheet in Part II.

Step 2. Gently scrape some material from the gray-green upper surface of the lichen onto a glass slide (tiny bits). Cover with a drop of 3% KOH (This solution is used in mycology studies to restore dried material). Scan the slide for evidence of 2 kinds of cells. Make an outline drawing with pencil of the cell types using the full page. Try to draw keeping the size relationships of the cells constant – maintain proportions. Label each as photobiont and mycobiont. How can you tell? Describe each cell type on the bottom of your drawing page. Hand in this drawing with your answer sheet.



Aside from being pioneer species, lichens are useful indicators of air pollution. They can indicate contamination of the air similar to the "canary in the coal mine". Most lichens will not grow in polluted air.


Examine the map of Great Britain below. (Adapted from Dobson, 1981)

Author did not include this map in her mailing to the NJ BISEC office


Note the key to the different zones and abundance of lichen species.

Zones 0 - 2

lichens absent or only 1-2 species confined to base of trunk

Zones 3 - 4

9-10 species common

Zone 5

13 species common

Zone 6 - 7

14-19 species common

Zone 8

20 species common

Zone 9-10

Zone 9-10

20 species common

25 to 30 species present to abundant


Match the zones to measured quantities of mean SO2 (sulfur dioxide) concentration (mg/m3 ) in winter . Use your answer sheet Part III. Using a reference map of Great Britain, answer the other questions in Part III of your answer sheet.




Lichen thalli are broadly classified by their general appearance into four major groups:

1. Crustose: wrinkled or cracked, thin crusts so closely attached to the substrate that you must take some of the rock or bark in order to collect the lichen.

2. Foliose: having leafy or flat lobes that are less firmly attached to the sustrate than the crustose type.

3. Fruticose: with upright or hanging, stalked, shrubby or hair-like thalli.

4. Squamulose: the thallus is made up of small scales.


Observe some actual specimens of lichens provided by the teacher. Try to identify what major group they belong to.

Lichens are further classified according to their dry color, macroscopic features, habitat, macrochemical tests and fluorescence. Consult How to Know the Lichens by Mason Hale (1979) for identification. Can you find any lichens in your neighborhood?

Look at the diagrams below and answer the questions in Part IV of your answer sheet. (Diagram source: Reader's Digest North American Wildlife 1982)

(see attachment b)

ANSWER SHEET Name ______________________________




Part I

1) Which objects involve the use of lichens as pigments? _________________________


2) Which object relates to lichens as sources of food in the tundra? _________________

Part II



AUTHOR DID NOT INCLUDE GRAPHIC THAT IS TO BE INSERTED HERE______________________________________________________________________


Figure A: Three Domains of Living Organisms proposed by Woese (Kaufman,1989)

1) In what domain would the mycobiont be found? _____________________________

2) In what domain would a green alga be found? _______________________________

3) In what domain would a cyanobacterium be found? ___________________________

Describe the cut surface of the foliose lichen thallus _____________________________



Part III

Can you match the quantities of mean SO2 concentration (ug/m3 ) in winter to the zones of lichen abundancy? Zones are on the map in part III.


ZONES SO2 conc. (mg/m3)

1. zones 0-2 _________ a) greater than 150-170

2.zones 3-4 _________ b) under 30

3. zone 5 _________ c) 65-75

4. zones 6-7 _________ d) 35-45

5. zone 8 _________ e) 50-60

6. zone 9-10 _________ f) 80-140

Look on another map of Great Britain and answer the questions below.

What towns or cities occupy zones 0 to 2? _____________________________________

What might be the cause of air pollution in these cities? ________________________

What kind of economic activity is found in the most unpolluted zone? _____________


Part IV

Look at the drawings in part IV. Read the descriptions given and name the group each lichen represents. (crustose; foliose; fruticose or squamulose)

A. _________________________

B. _________________________

C. _________________________

D. _________________________

E. _________________________