Wild Cucumber

• Wild cucumbers grow on vines that look similar to the cultivated cucumber.Hemera Technologies/Photos.com/Getty Images
  
  The wild cucumber (Echinocystis lobata) grows on vines that look similar to the cultivated cucumber with small, white flowers. They are hollow, inedible, covered with long, sharp spines and filled with hard black seeds. When the fruit ripens and dies, the seeds fall out through openings on the bottom of the fruits. You can find them almost all over the United States in forest habitats around mid- to late summer.
  
  

Durian

• nside the fruit are five segments with custard textured, yellow, orange or pink flesh with a unique flavor.Kevin Forest/Photodisc/Getty Images
  
  The durian is mostly cultivated in Southeast Asia and Malaysia. It is oval shaped and covered in sharp, painful spines and gives off an awfully bad smell. They can measure anywhere from 6 to 12 inches long, 5 to 6 inches wide and weigh up to 18 pounds. Inside the fruit are five segments with custard-textured, yellow, orange or pink flesh. The flavor is one that you must taste for yourself because it is indescribable. But most of the Asian, durian-eating population prize them highly because of their distinct flavor.
  
  

Prickly Pear

• The fruit comes in a variety of colors: white, green, purple, orange or red.Jupiterimages/Photos.com/Getty Images
  
  Prickly pear cacti are found in deserts everywhere. They bloom flowers that give way to fruit during spring and summer. The fruit comes in a variety of colors: white, green, purple, orange or red, depending on the species, and are covered in glochids and sometimes lots of spines. You know that the fruits are ripe when the glochids fall off. Some describe the taste as sweet yet tart and juicy.
  
  

Horned Melon

• Horned melons are mainly grown as an ornamental fruit in Africa, New Zealand and the United States.Stockbyte/Stockbyte/Getty Images
  
  The horned melon, also known as the kiwano, originated in Africa. They are typically orange and covered in thorns. The seeds are inside the fruit, floating in green, bland, jelly-like tissue. The horned melon is mainly grown as an ornamental fruit because it has a long shelf-life but is difficult to eat because of all the large seeds.