Teliospore

Teliospore (sometimes called teleutospore) is the thick-walled resting spore of some fungi (rusts and smuts), from which the basidium arises.

These terms apply when two hosts are required by a heteroecious rust fungus to complete its life cycle.

Teliospores are often dark-coloured and thick-walled, especially in species where they overwinter (acting as chlamydospores).

Here the wall is particularly thick at the tip of the terminal cell which extends into a beak in some species.

As the teliospore cells germinate, the nuclei undergo karyogamy and thereafter meiosis, giving rise to a four-celled basidium with haploid basidiospores.