III. THE DIFFERENT TYPES OF STEMS. 
Tt. pehfechestemms: 
Columnar or cylindrical type. 
I. Simple or branched, 
Sunflower, muilein, Lombardy poplar, royal palm, 
tree ferns, some cedars, arbor vitae. 
2. Advantages of the columnar habit. 
(1) Mere favorable fight relation. 
(2) Maintain same habit when with others as 
when alone. 
(3) Less competition for existence. 
Cone type. 
1. Main axis like a tall shaft. 
2. Branching of two types-— 
(1) False whorls 
Pines. 
Norway spruce. 
Douglas spruce. 
White pine. 
Growth movements ( Elongation of shoot. 
of young stems fe of leaves. 
Rate of growth—year marks. 
(2) Spiral or distributed. 
Hemlock spruce, Larch. 
(3) Advantages of the cone type. 
1. Less injury during high winds. 
2. Admit light to a larger foliage area. 
3. Less danger of injury from weight 
of snow. 
Oval type: 
Examples, oak, chestnut, apple. 
1. Main axis usually disappears. 
2. [Exhibit character of habit best during winter. 
3. Not so well adapted to higher altitudes and latitudes. 
4. Deciduous habit enables them to withstand winds 
better. 
Deliquescent type. 
Example—elin. 
Main axis and branches fork by false dichotomy. 
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