tree-logo.gif (7741 bytes) Plant Taxonomy (BIOL308)  -  Stephen G. Saupe, Ph.D.; Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321; ssaupe@csbsju.edu; http://www.employees.csbsju.edu/ssaupe/

Lab 1 - Plant Collecting Techniques

Objectives:  upon completion of today's lab you should be able to:

  1. describe appropriate techniques for collecting and preparing herbarium specimens

  2. compare and contrast specimens preserved by freezing, drying and chemical preservatives

  3. begin your plant collection

  4. identify poison ivy (and jewelweed)

Assignment Due:

Supplemental Readings:

Plants to Know:  We expect to see the following species during lab and these will be "fair game" on the PTK quiz/exam.  It is possible that other species may be included. 

Assignment Due Next Lab:  Turn in your Field Notebook.  This notebook should be a 3-ring binder dedicated to this course with a title page (Plant Taxonomy � Biology 308 Field & Laboratory Notebook, your name, address, phone) and dividers for three sections (Plant Collection; Lab Identifications; Family Quizzes).  In the plant collection section insert, in order:  Plant Collection Information handout, Plant Collection Grading Worksheet, a copy of the Herbarium Label template, a folded packet, and Field Record Forms for a each of the plants (minimum ten) that you�ve collected.  The specimens do not need to be identified.  However, the collection data does need to be complete (except for ID section).

Introduction:
     Preparing plant specimens is an important part of plant taxonomy.  As a consequence, each student will be required to prepare a collection of 20 specimens.  The purpose of today�s lab is to show you techniques used to make a plant collection for you to begin your plant collection.  Details about this assignment are provided in the General Information page for our course and the Plant Collection Information handout.  During lab we will complete the following exercises: 

Exercise 1 � Comparison of Preservation Methods
    In the lab there will be examples of specimens that have been prepared by pressing and drying (herbarium specimens), freezing and liquid preservatives.  Examine the specimens.  What are the advantages and disadvantages of each technique?  Which would be best to document the flora of a particular site?  Which would you use to study chromosomal number?  Which would you use to study DNA?

Exercise 2 � Assembling a Plant Press
    You will be assigned to prepare a collection of 20 herbarium specimens.  To complete this assignment you will need to assemble your plant press.  To do so: 

  1. Obtain a press frame with straps, 15 ventilators (cardboard sheets) and 28 dryers (blotters).

  2. Assemble your press as described, in the following sequence: frame � cardboard � 2 blotters � cardboard � 2 blotters � etc � frame.

  3. Bind the frame together with the strap.  If your frame has guides for the strap it is usually easiest to use only two on one side of the press or none at all.

Exercise 3 � The Vasculum
    After plants are collected in the field, most botanists place them in a plastic garbage bag to transport back to the lab.  A vasculum is a metal container that was once popular for transporting plants.  Examine the vasculum in lab.  In both cases, a damp paper towel or newsprint can be placed in the bottom to provide extra moisture/humidity.  What are the advantages and disadvantages of plastic bags versus the vasculum?

Exercise 4 � Collecting/Pressing Plants
    We will go into the field together to collect a few specimens to press.  Before heading into the field to gather plants, you will need to gather your collecting supplies including field notes, pen, digging tool, plastic bag or vasculum, pruners, GPS unit, clipboard, ruler(s) and other materials.  Once in the field, collect at least three specimens; one grass, one tree/shrub and one forb (non-grass herbaceous plant).  Record your notes.  Be sure to note the size of woody plants and to get the roots of herbaceous plants. Return to the lab and press the specimens that you collected.  I will provide more directions in class.  Prepare a �Field Record� for each specimen that you collect.  These should be placed in your Notebook in order.  Once your plants have been pressed, placed the press in one of our driers (stand it on edge) or feel free to take it home to collect on your own.      

Exercise 5 � Poison Ivy
    One plant that you�ll want to avoid contact is poison ivy.  In the field I will show you how to recognize Toxicodendron radicans (Western poison ivy).  You should be able to describe the habit, leaves and fruits of this plant.  Why does it cause dermatitis in sensitive individuals?  What chemical is responsible for poisoning?  What are some of poison ivy�s relatives?  Note:  there are a few other plants that cause dermatitis (wild parsnip) but they are not particularly common so we will not discuss them further.

Exercise 6 � Packet Preparation
    It is often necessary to make a packet for loose materials that separate from your specimens.  I will show you how to fold a typical packet.  Fold a packet using the paper provided and then punch holes along one side to insert into your Notebook.

Supplies Required

 

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Last updated:  09/29/2008 / � Copyright by SG Saupe