Leaf algae is a collective term for relatively large algaes. Wrack (opposite), knotted wrack and bladder wrack are some other common species. Some green and red algae are also included in this group, such as sea lettuce and Enteromorpha. In Virtuedata, we use the term leaf algae to distinguish it from the other group - filamentous algae. These groups are not systematically uniform - the designation is based on similarities in appearance.
Some seaweed species described in Aquascope:
Bladder wrack
Sugar wrack
Spiral wrack
Toothed wrack