Definition of "rhizoid" [rhi•zoid]

• A slender rootlike filament by which mosses, liverworts, and fern gametophytes attach to the substratum and absorb nourishment. (noun)
• A rootlike extension of the thallus of a fungus. (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.

• ""We were really excited when we saw how similar the ultrastructure of our liverwort rhizoid walls was to images of Prototaxites tubes published in 1976 by Rudy Schmid," Graham said."
• "B, Part of a developed protonema. h, Creeping filament with brown walls from which the filaments of chlorophyll-containing cells (b) arise; k, young moss-plant; w, its first rhizoid.]"
• "-- Types of colonies: a, Filamentous; b, rhizoid; c, conglomerate; d, toruloid.] (C) ~Surface Elevation."