Stomatal patterning in monocotyledons: Tradescantia as a model system

Stomatal patterning in monocotyledons is reviewed in two sections. Patterning is distinguished from stomatal development and results from Tradescantia are presented as a model organism for this plant group. The first section provides pertinent background information on theories of stomatal patterning, stomatal differentiation, monocot leaf growth, common stomatal arrangements, variations in patterning resulting from leaf position and environment, and stomatal types. The second section presents a developmental and mechanistic outlook to stomatal patterning based on published studies. A synopsis relates these data to the current patterning theories and a prospectus suggests areas of research likely to be profitable in understanding stomatal patterning in the future.