A genus of thin papery bright green seaweeds including the kinds called sea lettuce.

A green sheet-like seaweed commonly called "sea lettuce". Enteromorpha is another green algae that typically grows in long, thin green tubes. Both are found in eutrophic areas.

type genus of the family Ulvaceae; green seaweed having a thallus two cells thick: sea lettuce

Ulva is a privately owned island in the Scottish Inner Hebrides, off the west coast of Mull. Until the mid-nineteenth century its main industry was kelp collection and export. A church on the island designed by Thomas Telford dates from this period.