Melon classifications are so nebulous," says Laurie Todd, a farmer in Lansing, New York, who grows, by latest count, 19 different kinds of melons. That said, we can identify three basic categories of the fruit.
Most common in the United States is the muskmelon (Cucumis melo, reticulatus group). This type, which is often incorrectly identified as a cantaloupe, is characterized by a raised, netlike rind on the outside. Most muskmelons are orange inside, though some varieties have green flesh. Winter melons (C. melo, inodorus group), such as the honeydew or casaba, were traditionally harvested unripe and stored until Christmastime. They have a hard, smooth rind and delicate, fragrant, and often (as in the case of the honeydew) sticky flesh. The cantaloupe (C. melo, cantalupensis group) is named for Cantalupo, Italy, where supposedly this type of melon was first grown in Europe. Cantaloupes are recognized for their sweet flavor; and included in this category are the ogen, an Israeli hybrid with yellow skin, green stripes, and green flesh; the warty, archaic looking "true", or European, cantaloupe; and the smooth-skinned charentais, a derivative of the warty cantaloupe—and arguably the finest of all melons.
Charentais season in the U.S. begins in June, peaks, as it does in France, in July and August, and typically stretches into October. Expect to pay $1 to $3 apiece for charentais grown in the U.S.; imported French charentais can cost as much as $14 each. For ripeness, look for more of a beige than green color, and check the end opposite the stem for an alluring, musky aroma.