devoid of chlorophyll, also subterranean; and foliage 
leaves, larger and aerial. Flowers not formed. 
3. Mandrake, Solomon’s seal, Trillium, have scale leaves 
on fleshy underground stem; foliage leaves on 
aerial stems, bearing flowers. 
4. Grasses. 
5. Advantages of subterranean habit: 
Cr) * Protection trom, cold: 
(2) Protection from wind. 
(3) Protection from injury by certain animals. 
(4) Local migration: 
(5) Food storage in many forms. 
(6) Propagation. 
Specialized Shoots for Storage of food. 
Bulbs. 
ie Waderorounde 
Pe Net ale 
Examples, Easter lily, Chinese lilies, onion, tulip. 
Corms. 
Examples, Jack-in-the-pulpit (Arisaema) 
Tubers. 
Example, potato (Irish, not sweet). 
“Eyes” are buds on stem from which aerial shoots arise. 
Use—contains food for young sprouts. 
Undifferentiated stems. 
Examples, duckweed, Lemna, Wolffia. - 
IV.—FOLIAGE LEAVES 
Influence of foliage leaves on the form of the stem. 
Exercises great influence on form of stem. 
Without foliage leaves stems of green plants would develop 
different habits. Development would take place in three 
directions under influence of light— 
1. Profuse branching—Asparagus. 
2. Fewer branches and flattened. 
3. Massive trunks with few or no branches. 
Relation of foliage leaves to the stem. 
Phyllotaxy or arrangement of leaves. 
1. Note scars on winter shoots of woody plants. 
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