- Any of several edible seaweeds of the genus Ulva.
- Similar seaweed species of other genera:
- Monostroma spp., also known as the slender sea lettuce, a kind of algae.
- Scaevola taccada, also known as the beach cabbage, a terrestrial flowering plant species that is native to coastal regions of the Indo-Pacific.
- Dudleya caespitosa, also known as the sand lettuce, a terrestrial flowering plant species that is endemic to coastal areas of California
seaweed of genus Ulva
slender sea lettuce — see slender sea lettuce
beach cabbage — see beach cabbage
sand lettuce — see sand lettuce