[Sweet Basil, Genovese Basil, Mediterranean Basil, Ocimum basilicum (Mint family)]
This Basil is universally called for in European and American recipes. Formerly it was very easy to grow in season, but for awhile it often fell victim to fusarium wilt, caused by a soilborne fungus, Fusarium oxysporum f. sp. basilicum. Fusarium resistant varieties have been developed
Sweet Basil has decent keeping properties (almost a week if treated well). It is more aromatic and less sharp than Thai Purple Basil but the two can be used interchangeably in a pinch. I've even used Thai Purple Basil to make Italian Pesto because I can get piles of it cheap at ethnic markets while Italian Basil can cost several dollars an ounce in the supermarkets.
More on Basil.
If the basil you bought If it's a little wilted, it can be refreshed by cutting the stem ends off and immersing the entire bunch completely in cold water for about 1/2 hour. Then dry in your salad spinner and wrap loosely in plastic.
Fusarium infected soil should be sent to a landfill or sterilized by baking in the oven at high heat or by steaming because the fungus can hang on for another 8 to 12 years. Growing from seed was no defense - the fungus was spread by infected seeds, and there is no sure-fire way to certify them fusarium free.