Hormogonium

noun

1. In botany, a special reproductive body in the nostocs, having the form of a chain of roundish cells, from which new cœnobia are formed. Also hormogone, hormogon.
2. A chain of small cells in certain algæ, by which the plant is propagated.
3. A small, motile filament, formed by some cyanobacteria, that detaches and grows by cell division into a new filament