Definition of "thallophyte" [thal•lo•phyte]

• Any of a group of plantlike organisms showing no differentiation into stem, root, or leaf, including the algae, fungi, and lichens, formerly regarded as constituting a major division of the plant kingdom. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.