BIOL 3601: PLANT DIVERSITY
DR. JULIE R. ETTERSON
FALL 2013
Lab 4
Diversity in Deciduous Trees
Lab Goals:
To learn how to use a dichotomous key
To identify common native deciduous trees
Today we will continue refine our identification skills exploring deciduous trees using
the key “Minnesota Trees” produced by the U of MN Extension service. You will need
to be able to use this key to identify an unknown species by the end of lab.
You will need to use a hand lens and be very careful about how you answer questions.
Make sure to read all of the characteristics – some traits you will be able to see, some
you won’t. Some traits may look different than described because of the time of year or
the age of the structure or position on the tree (low vs. high in the canopy). You will
also need to use the razor blade to check several traits.
Hopefully, we will use the Key to Deciduous Trees with Leaves (page 25) but may also
need to use the Key to Trees without Leaves (page 75). There is also a Key to
Coniferous Trees (page 8) although we won’t use it today.
Exercise 1. Introduction to the key.
What you need:
1) For each pair of students one copy of: “Minnesota Trees.”
2) A sprig of the tree provided.
Helpful hints about the book:
1) The keys are flagged
2) There is a ruler on the back cover of the book.
3) Illustrations of leaf parts, leaf arrangement, and other leaf attributes is on page
19-20. Branch, twig and bud illustrations start on page 21 and fruit is on page
23.
List of terms
Leaf arrangement: Alternate, opposite, whorled
BIOL 3601: PLANT DIVERSITY
DR. JULIE R. ETTERSON
FALL 2013
Leaf types: Simple, palmately compound, pinnately compound, doubly compound
Leaf Margins: smooth, finely toothed, coarsely tooth, doubly toothed, lobed
Venation: Pinnate, palmate
Sap: Milky, clear
Pith: chambered in longitudinal section; round star-shaped or trangulate (shield
shaped), horseshoe shaped in cross section
Stubby spur shoots:
Odors: When checking for odors, crush a relatively fresh-looking twig or leaf. The smell
should be distinctive – not just a woody smell.
BIOL 3601: PLANT DIVERSITY
DR. JULIE R. ETTERSON
FALL 2013
Leaf Types
Leaf Venation
Leaf Arrangements
Leaf Shapes
Parts of the Twig
BIOL 3601: PLANT DIVERSITY
DR. JULIE R. ETTERSON
FALL 2013
Introductory Species in the Lab
Scientific Name: ________________________________________________________
Common Name:_________________________________________________________
Steps in the Key:
Distinctive features:
BIOL 3601: PLANT DIVERSITY
DR. JULIE R. ETTERSON
FALL 2013
Exercise 2. Identification of deciduous trees (one is an invasive)
We will key 7-8 native deciduous trees at Hartley Nature Center. Trees are marked with
pink flags.
1) Find each species.
2) Use your key to identify it. Ask questions if you need help. Check with the instructor
to make sure you have identified the species correctly.
3) Record the steps in the key you followed.
4) Draw a picture of distinctive features of each species.
Species 1
Scientific Name: ________________________________________________________
Common Name:_________________________________________________________
Steps in the Key:
Distinctive features:
BIOL 3601: PLANT DIVERSITY
DR. JULIE R. ETTERSON
FALL 2013
Species 2
Scientific Name: ________________________________________________________
Common Name:_________________________________________________________
Steps in the Key:
Distinctive features:
Species 3
Scientific Name: ________________________________________________________
Common Name:_________________________________________________________
Steps in the Key:
Distinctive features:
BIOL 3601: PLANT DIVERSITY
DR. JULIE R. ETTERSON
FALL 2013
Species 4
Scientific Name: ________________________________________________________
Common Name:_________________________________________________________
Steps in the Key:
Distinctive features:
Species 5
Scientific Name: ________________________________________________________
Common Name:_________________________________________________________
Steps in the Key:
Distinctive features:
BIOL 3601: PLANT DIVERSITY
DR. JULIE R. ETTERSON
FALL 2013
Species 6
Scientific Name: ________________________________________________________
Common Name:_________________________________________________________
Steps in the Key:
Distinctive features:
Species 7
Scientific Name: ________________________________________________________
Common Name:_________________________________________________________
Steps in the Key:
Distinctive features:
BIOL 3601: PLANT DIVERSITY
DR. JULIE R. ETTERSON
FALL 2013
Species 8
Scientific Name: ________________________________________________________
Common Name:_________________________________________________________
Steps in the Key:
Distinctive features: