One hundred and seventy four taxa belonging to 28 genera of desmids have been included in this work. Most of them are new records for Pakistan. Diagnostic characters of the families and the genera have been given. Keys are provided for all the taxes included in this study. Camera lucida drawings and photomicrographs of most of the taxes are given alongwith the diagnoses. The genera along with the number of taxes are Cosmarium (43), Closterium (24), Euastrum (22), Micrasterias (19), Staurastrum (13), Pleurotaenium (9), Xanthidium (7), Arthrodesmus (5), Staurodesmue (4), Desmidium (3), Tetmemorus (2), Cylindrocystis (2), Netrium, (2), Penium (2), Ryalotheca (2), Sphaerozosma (2), Spondylosium (2), Cocardium (1), Docidium (1), Triploceras (1), Spirotaenia (1), Mesotaenium (1), Bambusina (1), Phymatodocis (1), Gonatozygon (1), Streptonema (1), Cosmocladium (1), and Onychonema (1).
In all,400 samples containing desmids were collected from all over the country. The more widely distributed taxes are Desmidium ewartzii collected from 5 localities, Bambusina brebissonii from 4, Tetmemorue brebissonii from 4, Hyalotheca dissiliens from 3, Cosmarium botrytis from 3, Euastrum Oblongum from 3, Penium margariČtaceum from 3, and Netrium digitus from 3. The more common genera are Cosmarium and Closterium.
The nomenclature of all the tare is according to the Rules of International Botanical Nomenclature. Riddles of nomenclature have also been solved whenever found necessary. Some extremely rare desmids have also bean collected and included in this work.
This study is primarily based on field collections. Some taxa, however, had to be cultured in the laboratory to determine the exact identity. These taxa are mostly from basic waters.