Non-GMO, Heirloom Lettuce Leaf Basil Herb Seed from True Leaf Market. Ocimum basilicum. As basil has many different varieties, Lettuce Leaf Basil is a sweet cultivar that comes from Japan and has a similar to Italian basil. This type of basil develops crimped, 5" bright-green leaves with thicker stems"giving off a sweet scent. Lettuce Leaf Basil has been used as medicinal remedies to help digestion. This herb is popular as a fresh addition to salads and an ideal ingredient in Asian cuisine. With its mild verdant flavor and abundant growth, this type of basil also makes a perfectly crisp lettuce for sandwiches and savory chicken wraps.