A number of classification systems have been used for the Chlorophyta, the most widely used being based on artificial criteria that are not supported by more recent ultrastructural and molecular biological evidence. The most common grouping of the green algae into orders is based largely on organizational level, something which shows only marginal relationship to phylogeny. There have been a lot of publications on the higher-level classification of the green algae in recent years, and there is as yet no general agreement on a system to use. It is beyond the scope of this module to delve deeply into green algal classification, but there are at least some groups of greens that any serious student of botany should be familiar with. The following links provide information on green algal classification, and should be explored further.

	The Chlorophyta from a largely traditional viewpoint. Warning: this site treats the algae as a subkingdom, the Phycobionta. What problems do you see with that approach?
	The ultra-traditional phylogeny according to Prescott (1966) is given as the classification system.
	An introduction to the Green Algae. This is the University of California website material on green algae.