Algae | Bryophytes | Pteridophytes | Gymnosperms | Angiosperms Coleochaete sp. Coleochaete is a soil alga in the order Coleochaetales, subfamily Charophyceae, of the Chlorophyta, or green algae.  This alga produces a small vegetative thallus as the major, haploid part of its life cycle. This thallus produces egg cells toward its periphery. Once the eggs are fertilized, the zygotes are retained in this position on the parent thallus and supplied with nutrients through specialized transfer cells.  Many people think that Coleochaete is an excellent model for the algal ancestor of land plants and may be a modern representative of the algal group that gave rise to the land plants. In this picture you can see the characteristic appearence of Coleochaete, with its pattern of vegetative cells radiating from the center of the thallus. On the periphery are the larger egg cells. Citations Graham, LE. 1993. Origin of land plants. John Wiley & Sons, New York. Arizona State University | Department of Plant Biology