|Hello! I am a fourth grade teacher in San Antonio. My science class is learning about plant reproduction and a question came up that I couldn't answer. The students realize that most fruits and vegetables have seeds which are surrounded by their own protective covering- the fruit. We couldn't figure out where the seed(s) of a head of lettuce would be. We would really appreciate your help.
San Antonio, TX
|Yours is an interesting question and one that many people ponder over. When we plant lettuce seeds, we expect to harvest leaves in a few weeks. Because we prefer to eat young, tender leaves, we generally harvest when the plant is still immature. If lettuce plants are allowed to mature completely they will form a flowering stalk which emerges from the center of the plant. This stalk develops 10-25 individual flowers, and each flower will produce one seed.
When lettuce is grown under cool conditions, such as spring or autumn, it takes a long time for a flower stalk to develop. But lettuce growing in cool spring weather can suddenly 'bolt', or go to seed, when warmer summer weather arrives. Once a lettuce plant has developed a flower stalk the leaves become tough and bitter, as the plant puts all of its energy into producing seed.
Hope this answers your question!