Karyological studies of seven populations of Buxus hyrcana Pojark. from different habitats are presented. We found one usual basic CHROMOSOME number in this species x=14. All populations were diploid (2n = 2x = 28). The results of kryotypic analysis made it possible to categorize different populations of a species and make a logical comparison among them.

CHROMOSOME NUMBERS of two native species from Iran were determined. The samples were collected from natural habitats. Astrodaucus orientalis (2n=20) of Apiaceae family and Althaea officinalis (2n=42) of Malvaceae family were investigated in this research. Ideograms were depicted for each species. Althaea officinalis had metacentric CHROMOSOMEs. In Astrodaucus orientalis the karyotype formulas are 8m+ 2sm. These results are the first report for the Iranian flora.

CHROMOSOME NUMBERS were determined for the first time for 2 native species of Iran. The samples were collected from natural habitats.Paronychia kurdica (2n=18) of Caryophyllaceae family and Salsola yazdiana (2n=18) of Chenopodiaceae family were examined in this study. Ideograms were depicted for each species. Both of them had metacentric CHROMOSOMEs.

Mitotic CHROMOSOME NUMBERS of 5 taxa of the genus Persicaria (L.) Mill. is reported for Iran for the first time.Subspecies of P. lapathifolia showed 2n=22 CHROMOSOME number supporting the earlier report while the CHROMOSOME NUMBERS of P. minor and P. mitis are 2n=40. Results are compared with previous records.

This study includes 4 reports of CHROMOSOME counts in Tripleurospermum Sch. Bip. belonging to the tribe Anthemideae of the family Asteraceae from Iran. Confirming the reported base number of x=9 for this genus, the species studied include diploid and tetraploid species. CHROMOSOME counts for three species are reported for the first time from Iran.

CHROMOSOME NUMBERS of three native species of Prosopis are presented. They include first counts from Iran for Prosopis cineraria and Prosopis farcta, both of which show diploidy by 2n= 28, and first record of Prosopis koelziana show diploidy and tetraploidy. CHROMOSOMEs were counted from thirty populations of Prosopis distributed in South Iran.

CHROMOSOME NUMBERS are reported for Ranunculus dolosus (Ranunculaceae), 2n=32 and Silene conoidea (Caryophyllaceae), 2n=24. These species were collected from NW Iran in W Azarbaijan Province. Idiograms were prepared for both species. Symmetrical karyotypes are placed in class 1B in Ranunculus dolosus and class 1A in Silene conoidea. Karyotype formula are 8m+6sm+2st in Ranunculus dolosus and 12m in Silene conoidea.

CHROMOSOME NUMBERS are given for six taxa of Eremopyrum (Ledeb.) Jaub. & Spach (Poaceae) of Iran: E. bonaepartisvar. bonaepartis (Spreng.) Nevski (2n=14 & 28), E. bonaepartis var. sublanuginosum (Drobow) Melderis (2n=28), E. confusum Melderis var. confusum Melderis (2n=28), E. confusum Melderis var. glabrum Melderis (2n=14), E. distans (C. Koch) Nevski (2n=14) and E. orientale (L.) Jaub. & Spach (2n=28). CHROMOSOME NUMBERS of six studied taxa were recorded for the first time from Iran.

CHROMOSOME NUMBERS of 15 species of Plantago L. of Iran were investigated. They include first counts for 2 taxa: P. stocksii Boiss. (2n=10) and P. loejlingii L. (2n=24), as well as 3 new CHROMOSOME NUMBERS for 3 taxa: P. albicans Boiss. (2n=8 & 10), P. coronopus L. subsp. commutata Pilger. (2n=10) and P. coronopus subsp. Coronopus Pilger (2n=20). Diploid CHROMOSOME NUMBERS of the taxa investigated varied between 2n=8 and 2n=24. Our results are compared with previous records.

The present study reports somatic CHROMOSOME NUMBERS of 7 species belong to 6 families from Iran. The CHROMOSOME NUMBERS of Epilobium palustre (2n=36), Geranium pyrenaicum (2n=26), Sium sisarum (2n=20), Veronica beccabunga (2n=18) were reported for the first time for the flora of Iran. Ferula persica (2n=22) and Tragopogon jesdianus (2n=12) are reported for the first time. The report for Bromus scoparius (2n=28) is the second count for the species in Iran. Ideograms are depicted for each species.