TOPICS:  Plant identification, classification, and natural history

LEVEL:  Middle and high school

TIME:  One period

ADVANCE PREPARATION:  Collect twig samples from up to 6 different species of evergreen trees found in either the northeastern or western version of the "Key to Conifer Trees".  Label the twigs with letters on masking tape tabs.  Make a photocopy of the picture page and the student data sheet.  Cut out the pictures of the twig species you collected without their names and paste them on the data sheet master.  Make a copy for each student. DO NOT distribute the student data sheet without the appropriate pictures !

STEP B: Students unfamiliar with dichotomous keys may need help getting started.  You may wish to identify the first species together as an example .

STEP C: Encourage (or assign) students to take the key and their data sheet home with them to help them identify conifer trees they find outdoors.

GOING FURTHER:  You may wish to discuss in class how animals in winter use conifer trees.  Deer, rabbits, hares, and spruce grouse feed on some conifers; chickadees, robins, blackbirds, grouse, deer, and hares sleep in the protection of conifers.

QUESTIONS :

1. A dichotomous key is a tool to identify objects such as species of conifer trees .

2. Conifers have needlelike leaves, and produce their seeds in cones.  Most are evergreen .

3. Pines have needles in clusters whereas other conifers are attached singly to the twig (see couplet 5 in northeastern key or couplet 7 in western key) .

4. The different species of pines can be identified by the number of needles per cluster, their size, and color .

5. Common conifer species will differ with location, but may include hemlock, pines, fir, spruce, tamarack .

6. Answers will vary.  Cedar and yew are common hedges.  Spruce and pine are commonly planted in yards .

7. Scotch pine, white spruce, and balsam fir are commonly used as Christmas trees.  Tamarack is not used because it sheds its needles in the fall.