PART l.-PLANTS 



LABORATORY AND FIELD EXERCISES 



PRELIMINARY SURVEY 

 I. Light Relation of Leaves 



An erect stem with opposite leaves (Coleus). 



a. Horizontal view showing stem (nodes and internodes) and leaves. 



b. Make a diagram showing arrangement of leaves as seen from 

 above. How many vertical ranks are there? 



An erect stem with whorled leaves (Galium). Horizontal view as 



in la. 



An erect stem with alternate leaves (Quercus). 



a. Horizontal view as in za. 



b. Diagram as in ib. 



Leaf Rosette (Plantago) as in ib. 



Horizontal stem with alternate leaves (Castanea). Vertical view 



showing carefully how each leaf is connected with the stem. 



Horizontal stem with alternate leaves (Tropaeolum) . Horizontal 



view. Show relation of leaves with stem as in 5. 



Leaf Mosaic (Ampelopsis Veitchii) seen from the direction of the 



midday sun. 



Inverted stems. 



a. Wistaria. Relation of leaves to stem (note the pulvinus). 



b. Salix Babylonica. Relation of leaves to stem. 



H. Form of the Plant as Related to Light 



a. Form of a tree in an open space (Pinus). 



b. Form of same kind of tree growing in a thicket. Note difference 

 in lower branches in a and b and explain. 



An excurrent type of stem (Populus). 

 A deliquescent type of stem (Ulmus). 



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