Fruits and Seeds 259 



the apparent number of cotyledons in the embryo, whether there 

 are one or two. Any one who has watched plants beginning to 

 grow in a garden will recall the two cotyledons of the bean, 

 pumpkin, sunflower, and radish, raised above the soil. Seeds, 

 of fruits, of our broad-leafed forest trees — maple, ash, tulip, 

 linden — may be readily secured and germinated, and they too 

 will be seen to be dicots. It will also be recalled that these plants 

 have net-veined leaves. 



The cotyledon of a monocot is usually an absorbing organ that 

 remains below the ground in contact with the endosperm, and in 

 wheat, corn, and other grasses it is the first leaf that appears 

 above the ground — not the cotyledon. In other monocots, like 

 the onion, the cotyledon is leaf-like and rises above ground. 



The two groups differ in their flowers also. In the monocots 

 the number of parts of the calyx and corolla is usually three, and 

 the stamens and divisions of the pistil are three or some multiple 

 of three. In the dicots the parts of the flower are typically in 

 fives or fours, or in a multiple of these. 



Thus the names ''monocot" and "dicot" relate to the form 

 of the embryo ; but the two groups are further distinguished by 

 differences in leaf venation, bundle structure, bundle arrange- 

 ment, and flower plan. 



The gymnosperms and angiosperms. We have previously 

 learned that the conifers bear their seeds on scale leaves arranged 

 in cones (page 232). A study of one of these cones shows that the 

 seeds are formed on the upper surface of the scales and are not 

 inclosed in capsules. When the scales mature and become dry, 

 the cone opens and the seeds fall out. The word " gymnosperm " 

 means "naked seed," and this is the group name for the conifers 

 and all other plants whose seeds are not inclosed in an ovulary. 



The angiosperms are what we usually call the flowering plants, 

 although some of them, like the grasses and many forest trees, 

 produce small, inconspicuous flowers without colored parts. 

 The seeds of an angiosperm, in contrast to those of the gymno- 



