Dichotomous Key Lab Activity
1
2
3
4
5
a. Vascular tissue is present- Veins in leaves and stems……...............Go to #3
b. Vascular tissue is not present ……………….......………………..Go to #2
a. Spongy, tiny leaf like appearance…………….…………Bryophyta (moss)
b. Horn-like structures…….….............………...................Anthocerophyta (hornworts)
c. Deeply grooved lobes…….………...………….….........Hepatophyta (liverworts)
a. Spores under or attached to leaves or stems…..………..Go to #4
b. Flowers or fruit…………….....………………..............Anthophyta (angiosperms)
c. Presence of cones……………………...……………....Go to #5
a.
b.
c.
d.
Grow in club-like clusters……………..…………............Lycophyta (club mosses)
Large fronds…………..………………………………...Pterophyta (ferns)
Stems with no leaves, whisk-like appearance….................Psilophyta (whisk ferns)
Reed-like appearance of leaves and stems.…....................Sphenophyta (horsetails)
a.
b.
c.
d.
Palm-like leaves, cone/s in the center…………….……..........Cycadophyta
White/silver fruit-like cones that emit foul odor…..…...............Female Ginkgophyta
Needle-like leaves and cones………………………..………Coniferophyta
Pollen tubes from one cone to another……………………….Gnetophyta
Dichotomous Key Lab Activity FormHypothesis: My hypothesis is that there will be more plants that are Angiosperms than
bryophytes, pteridophytes, and gymnosperms.
Data:
Location
Plant sample 1
Plant sample 2
Plant sample 3
Plant sample 4
My backyard
My backyard
Physical Description
Green; rough; strawberries & flowers on it
Light green; layered; big sphere in middle
Phylum
Anthophyta
My backyard
My backyard
Anthophyta
Analysis Questions:
1. What characteristics allowed you to identify each of your plant samples?
A characteristic that allowed me to identify my plant samples is the way that their
leaves are shaped.
2. To which division does each of your plant samples belong and why? [Nonvascular
(Bryophytes), Seedless Vascular (Pteridophytes), Nonflowering Plants (Gymnosperms),
or the Flowering Plants (Angiosperms)]?
3. Was your hypothesis correct? Did you have more of one type of plant over another? If
so, why? Conclusion:
4. Why is it important to know the division or phylum of the various plant species growing
in your backyard?
It is important because you want to make sure that none of the plants are poisonous or
can be harmful to you and your family.