https://www.umass.edu/agriculture-food-environment/vegetable/fact-sheets/lettuce-endive-escarole
Lettuce, Endive, and Escarole : Vegetable : Center for Agriculture, Food, and the Environment...
There are four general types of lettuce recognized as subspecies. All are extremely sensitive to high temperatures. Lettuce will germinate at soil temperatures...
endive and escarolefor agriculturelettucevegetable