While the terminology of the units has still not been fixed, researchers mostly followed the procedures of the Braun-Blanquet approach: studied releves and described floristically delimited units for the thallophyte vegetation using the rank-indicating terminations of the ICPN (-etum, -ion, -alia, -etea).
The extensive number of already described thallophyte syntaxa shows that construction of a meaningful syntaxonomic system for the thallophytic vegetation is feasible (see also WILMANNS, 1998).
In Pringsheim's (1876b) experience, the first neutral generation of thallophytes (i.e., the spore-producing thallus that develops from the fertilized egg) often proceeded directly to spore-production, with greater or lesser suppression of the vegetative parts relative to subsequent neutral generations.
Homologous alternation occurred in most thallophytes and "might be described as a mere differentiation--often a very slight one--of successive gametophytes." In support of his theory, Bower disputed the hitherto generally accepted homology between the zoospores of thallophytes and the spores of archegoniates.
A consideration of the evolutionary and taxonomic significance of some biochemical, micromorphological and physiological characteristics in the Thallophytes