CaseyHoo being the proud owner of that picture.. should know that..
It can root itself to the wood/rock.. almost like a type of moss.. it produces new leaves as it goes.. exotic plant.. but it is good as a collection.. I cannot imagine seeing this plant in IALPC contest winner's tank.. would look like algae from far..
This is a red algae (rhodophyte) of the genus Caloglossa (Family Delesseriaceae). There are a few aquarists in Germany with probably the same odd algae. Such kind of algae also turned up at one of my tanks ca 10 years ago in Berlin. Dr. Maike Lorentz (phycologist, University of Goettingen, Germany) detected it as a Caloglossa, and I've tried to identify it with a book about freshwater red algae, and it seems to be close to Caloglossa beccarii. But there are a few characters that don't fit. Therefore I call my red algae Caloglossa cf. beccarii.
Most caloglossas grow in warm regions of the world at coasts in brackish or seawater, e.g. on mangrove trees. But there are a few freshwater species, too.
Another odd red algae in aquariums is Thorea. But it does not consist of leaflet-like structures but of thick slimy strings.