Main Page | See live article | Alphabetical index A class of green algae, distinguished mainly on the basis of ultrastructural morphology. The sea lettuce, Ulva, belongs here. They are divided into the following groups: Order Ulotrichales (e.g. Ulothrix) Order Ulvales (e.g. Ulva) Order Siphonocladales Order Dasycladales Order Caulerpales This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.