I. The Simple Fruits (page 3)

A fruit, classified as simple, always develops from a single ovary containing one or more carpels and may or may not include additional modified accessory floral structures. Simple fruits are either fleshy or dry. Dry fruits are classified as either dehiscent or indehiscent. Dry dehiscent fruits crack open along two seams and shed their seeds into the environment when the fruit is ripe. We will examine three common kinds of dry fruit.

  B. Simple Dry Dehiscent Fruits

1. The Legume

The legume splits along two lines of dehiscence following maturation and drying. The legume type fruit is derived from a simple ovary (one carpel) with two rows of ovules. This type of fruit structure is characteristic of peas, beans and peanuts. The peanut is one of the few legumes that does not split open when ripe. This is probably because the fruit of the peanut develops in the soil rather than in the air.

2. The Capsule

 

 
 The capsule is another type of dry dehiscent fruit. Unlike the legume, the capsule is composed of more than one carpel. Fruits like the lily split length-wise into sections corresponding to the number of carpels. The Sweet Gum fruit, being a cluster of capsules, releases winged seeds as each ovary cracks open at maturity.

3. The Follicle

 

 
 Columbine and milkweed plants produce fruit that is known as a follicle. Fruit of the Follicle type develop from a single ripened ovary and split once to release their seeds. The split is always lengthwise, along one edge of the carpel. Legumes you remember split along two edges of the carpel. Follicles may occur singly (milkweed) or in clusters (columbine). When the fruit opens it resembles a dry leaf and reminds us that carpels are modified leaves that first produce spores, then gametes and finally seeds.

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