Table I. Stomatal complex types recognized from mature stomata and used in taxonomy and systematics from Cleal and Shute (2012) and Rudall et al. (2013).

See the Cuticle Database (http://cuticledb.eesi.psu.edu/) and Barclay et al. (2007) for illustrations of mature stomatal types.

Descriptive Mature Stomatal Complex Types	Examples of Extant and Extinct Taxa
Stomata Absent	Liverworts
Anomocytic	Hornworts, mosses, rhyniophytes, lycophytes
Lacking subsidiary cells	Trimerophytes, Psilotaleae, Ophioglossaceae, Polipodieae, progymnosperms, paleozoic pteridosperms, Medullosales, Ginkgoales, Peltaspermales, Cycadales, Cordaitales, Coniferales, Gnetales, Glossopteridales, Caytoniales, angiosperms
Stephanocytic	Marattiales, Corystospermales (incomplete ring)
An encircling ring of subsidiary cells	Ginkgoales, ?Cycadales, ?Cheirolepidaceae, ?Peltaspermales, Glossopteridales, Caytoniales, Medullosales
Paracytic	Equisetales, Corystospermales, Gnetales, Bennettitales, angiosperms, Medullosales
One or more pairs of lateral subsidiary cells orientated parallel with guard cells
Anisocytic	Angiosperms (e.g. Peperoma), Marattiales
Three subsidiary cells surrounding guard cells, one of which is smaller than the other two