There are 30 species of mint, but the two most commonly available are peppermint (more pungent with bright green leaves, purple stems and peppery flavor) and spearmint (gray-green leaves and milder flavor).
Season: June - August
How to select: Available year round, but summer is height of the season. Look for even-colored leaves.
How to store: Keep stems down in a glass of water with the leaves covered in plastic for a week changing the water every 2 days, or in plastic with a damp paper towel.
Matches well with: carrots, chocolate, duck, eggplant, fruit, goat, ice cream, lamb, lentils, oranges, peas, peppers, pilafs, pork, salsas, tomatoes, vegetables, yogurt
(from Kitchen dictionary)