Review Article
Ali Abbas Rather, Asma Band
Abstract
Extensive cytological studies had revealed the presence of diploid, tetraploid, hexaploid and octaploid species in the Family Lamiaceae. Chromosome numbers vary from 2n=2x=14 in Salvia nemorosa to 2n=6x=102 in Stachys palustris L. Diversification in the Family may be attributed to the presence of polyploidy and aneuploidy. It is an eurypalynous family with pollen grains usually radially symmetrical, isopolar, prolate-spheroidal to oblate-spheroidal or sub-oblate to sub-prolate. Xenogamy is deeply rooted, and protandry or gynodioecy, especially frequent in this family, maximizes cross-fertilization. Fruits consist of four oneseeded nutlets (mericarps) formed within a persistent calyx, with seeds dehiscing during the warmer months. Individual seeds are characterized by a prominent attachment scar that is known as a mericarp plug