There are two groups of Desmids: the "Placoderm" and the "Saccoderm" Desmids.

Placoderm desmids have cells composed of two halves (semicells), often almost divided from each other by deep median incisions. The cells are symmetrical about 3 planes, and often bear elaborate ornamentation. Genera are Cosmarium, Cosmocladium, Euastrum, Micrasterias, Staurastrum, Staurodesmus, Xanthidium.

Saccoderm desmids are simple shapes, cylindrical or spindle-shaped, rarely with any median constriction. This group forms the family Mesotaeniaceae and includes the genera Cylindrocystis, Mesotaenium, Netrium, Roya, Spirotaenia, Tortitaenia, and, in the suborder Closteriinae, Closterium, Gonatozygon and Penium, and in the suborder Desmidiinae, Actinotaenium.

Cosmarium	Cosmocladium	Euastrum	Micrasterias	Staurastrum	Staurodesmus	Xanthidium
Saccoderm:	Closteriinae		Mesotaeniaceae		Desmidiinae

	STAURASTRUM	Unicellular Desmid: semicells without marginal incisions or spines, but have many small processes and arms tipped with spines (2 or more arms per semicell)
		Staurastrum anatinum
		Staurastrum arctiscon
		Staurastrum armigerum fo. furcigerum
		Staurastrum asperum
		Staurastrum avicula
		Staurastrum bieneanum
		Staurastrum ?cerastes
		Staurastrum chaetoceras
		Staurastrum cingulum
		Staurastrum ?cingulum v. obesum
		Staurastrum ?dilatatum
		Staurastrum ?furcatum
		Staurastrum gracile
		Staurastrum ?hirsutum
		Staurastrum ?hirsutum v. muricatum
		Staurastrum inflexum
		Staurastrum johnsonii
		Staurastum longispinum
		Staurastrum lunatum
		Staurastrum manfeldtii
		Staurastrum ophiura
		Staurastrum planctonicum
		Staurastrum polytrichum
		Staurastrum proboscideum
		Staurastrum pseudopelagicum
		Staurastrum sexangulare
		Staurastrum teliferum

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John Kinross