Page:First course in biology (IA firstcourseinbio00bailrich).pdf/117



Describe the leaves. For what is the plant used?

you know of parallel-veined leaves that have lobed or dentate margins? 60. What becomes of dead leaves? 61. Why is there no grass or other undergrowth under pine and spruce trees? 62. Name several leaves that are useful for decorations. Why are they useful? 63. What trees in your vicinity are most esteemed as shade trees? What is the character of their foliage? 64. Why are the internodes so long in water-sprouts and suckers? 65. How do foliage characters in corn or sorghum differ when the plants are grown in rows or broadcast? Why? 66. Why may removal of half the plants increase the yield of cotton or sugar-*beets or lettuce? 67. How do leaves curl when they wither? Do different leaves behave differently in this respect? 68. What kinds of leaves do you know to be eaten by insects? By cattle? By horses? What kinds are used for human food? 69. How would you describe the shape of leaf of peach? apple? elm? hackberry? maple? sweet-gum? corn? wheat? cotton? hickory? cowpea? strawberry? chrysanthemum? rose? carnation? 70. Are any of the foregoing leaves compound? How do you describe the shape of a compound leaf? 71. How many sizes of leaves do you find on the bush or tree nearest the schoolroom door? 72. How many colors or shades? 73. How many lengths of petioles? 74. Bring in all the shapes of leaves that you can find.