Zygnematophyceae

Zygnematophyceae (or Conjugatophyceae) is a class of green algae in the division Charophyta. It contains the order Zygnematales. The Desmidiales emerged within the Zygnematales. The Zygnematophyceae are the sister clade of the Mesotaenium, together forming the sister clade of the land plants. Sexual reproduction in the Zygnematophyceae takes place through a process called conjugation. Here cells or filaments of opposite gender line up, and tubes form between corresponding cells. The male cells then become amoeboid and crawl across the female, or sometimes both cells crawl into the connecting tube. The cells then meet and fuse to form a zygote, which later undergoes meiosis to produce new cells or filaments. As in plants, only the female passes its chloroplasts on to the offspring.