EXERCISE 101 

 VEGETATIVE STRUCTURE OF THE PINE 



Materials. Branches with leaves and cones ; sections of wood 

 and leaves, either free-hand or microtome cut. 



Directions for work. Determine whether the pine tree is 

 structurally well equipped with the tissues needful to perform 

 its nutritive work in competition with the flowering plants. 

 Proceed as in the study of mosses and ferns. 



Examine standing trees with regard to the extent of root 

 system, the height and strength of stems, and the amount of 

 leaf surface. 



Examine the leaves and stems in more detail, comparing with 

 your descriptions and drawings of leaves and stems of flowering 

 plants and ferns. 



1. Leaves. Note arrangement in clusters and number in each 

 cluster. Note size and shape of leaves. Ascertain the facts 

 regarding epidermis and cuticle, palisade tissue, stomata and 

 internal air passages, and veins. Do the leaves seem suited to a 

 dry climate or a moist one ? Is the cold northern winter a dry 

 or a moist season so far as the leaves are concerned? 



2. Stem. Compare the gross and microscopic structure of the 

 wood with that of dicotyledonous stems (Exercise 7), using 

 your notes and drawings. What are the points of resemblance 

 between gymnosperm and dicotyledonous stems ? What are the 

 points of difference ? 



3. How well equipped does the pine tree appear to be in com- 

 parison with the flowering plants studied earlier in the course ? 



Look up the facts of the actual success of the pines and see 

 whether the facts agree with your conclusion given above. 

 Refer to textbooks, encyclopedias, geographies, etc. Note such 

 facts as the geographic distribution of the pines, the area of 

 the pine forests, the abundance of individuals in the forest, 

 and the size and age of individual trees. 



References 



BERGEN and CALDWELL. Practical Botany, pp. 299-306. 

 BERGEN and CALDWELL. Introduction to Botany, pp. 268-289. 



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