DESMIDS
Phylum Chlorophyta; sub-phylum Chlorophyceae; Order Zygnematales
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.
Saccoderm: ILLUSTRATIONS:
Saccoderm: Closteriinae
Closteriiniae:Closterium |
unicellular Desmid, varying from crescent shaped to straight: radius of curvature, dimensions and wall ornamentation distinguish species |
Closterium ?abruptum | |
Closterium acerosum | |
Closterium aciculare | |
Closterium angustatum | |
Closterium attenuatum | |
Closterium baillyanum | |
Closterium closterioides | |
Closterium cornu | |
Closterium costatum | |
Closterium dianae | |
Closterium dianae v. minus | |
Closterium dianae v. pseudodianae | |
Closterium directum | |
Closterium ehrenbergii | |
Closterium gracile | |
Closterium gracillimum | |
Closterium idiosporum | |
Closterium incurvum | |
Closterium intermedium | |
Closterium jenneri | |
Closterium juncidum | |
?Closterium juncidum v. elongatum | |
Closterium kutzingii | |
Closterium lebleinii | |
Closterium littorale | |
Closterium lunula | |
Closterium moniliferum | |
Closterium navicula | |
Closterium ? parvulum | |
Closterium praelongum | |
Closterium ralfsii | |
Closterium setaceum | |
Closterium striolatum | |
Closterium venus | |
Closteriiniae: Gonatozygon |
|
Gonatozygon kinahanii | |
Gonatozygon monotaenium | |
Closteriiniae: Penium |
Unicellular Placoderm Desmid: cylindrical with rounded ends, cell wall granular, 1 chloroplast in each semicell (sometimes interrupted in P. margaritaceum). |
Penium exiguum | |
Penium margaritaceum | |
Desmidiinae
(suborder) : Actinotaenium
|
|
Actinotaenium curtum |
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