Like all lettuces, romaine is extremely low in calories and high in water content (about 95 grams in 1 cup). However, romaine packs a larger amount of vitamins, minerals, fiber, and phytonutrients than other popular types of lettuce. The fiber, vitamin C, and beta-carotene content makes romaine an especially good vegetable for heart health. High amounts of folate and potassium add to the heart benefits. Romaine is also an excellent source of lutein, a yellow-colored phytonutrient found to be important to eye health. Heirloom. Developed at a Clemson University experiment station in 1951, this lettuce earns a spot with gardeners as the classic romaine. Its compact, dark green rosette of tall, upright leaves is slightly curly with white hearts and has a crisp, sweet flavor. Slow to bolt. Grows best in full sun, but will tolerate partial shade and even appreciates it in spring in hot climates. Resistant to mosaic.  Light: Full sun to part shade  Head size: 8 inches (semi-heading)  Matures: 21 days for leaves, 75 for head  Plant spacing: 10 to 18 inches apart  Plant size: 1 foot tall and wide