the branch of ecology dealing with the origin, composition, structure, and classification of plant communities.
Origin of phytosociology
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
the branch of ecology that is concerned with the origin, development, etc, of plant communities
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012