MULTIPLICITY FROM SIMPLICITY. “Since each of these three multicellular variants can involve diffuse, trichothallic, intercalary, or apical cell divisions, or some combination of all four, a large number of multi-cellular body plan variants can be codified (i.e. 3 cell division planes, 5 meristematic locations, 15 variants de minimis), although the usefulness of doing so is questionable.”
http://aob.oxfordjournals.org/content/85/4/411.full.pdf