Table 1.

Glossary

Term	Definition
Amplifying division	Further asymmetric division of a meristemoid that creates two daughter cells: an SLGC and a meristemoid or GMC
Guard cells (GCs)	Pair of cells that together delimit the stomatal pore
Guard-mother cell (GMC)	Final stomatal precursor cell; divides symmetrically to form a pair of guard cells (GCs)
Lateral subsidiary cell (LSC)	Modified neighbour cell located laterally adjacent to a guard cell; can be mesogenous or perigenous
Meristemoid	Specialized precursor cell that typically divides asymmetrically
Mesogenous neighbour cell (or subsidiary cell), also termed stomatal-lineage ground cell (SLGC)	Neighbour cell derived from the same lineage as the GCs
Perigenous neighbour cell (or subsidiary cell)	Neighbour cell derived from a different cell lineage from the GCs (e.g. grass LSCs)
Quartet pre-patterning	Protodermal cells in groups of four, roughly arranged in a square or rectangle, resulting from development whereby each cell divides symmetrically across its narrowest width, usually perpendicular to the previous division