POLLEN DIMORPHISM IN 3 TEUCRIUM SPECIES (LAMIACEAE)

In the Iberian Peninsula and Balearic Islands pollen dimorphism was found in Teucrium fruticans L., T. pseudochamaepitys L., and T. rotundifolium SCHREBER. Generally, this dimorphism shows two sizes of pollen grains, the smaller more or less collapsed. The percentage of pollen viability is calculated. Differences in size between viable and nonviable pollen grains are similar, being about 40% in T. fruticans and T. pseudochamaepitys, and about 26% in T. rotundifolium. With regard to pollen viability, the percentage of male sterility is higher in T. fruticans, in which from male sterile (ms) plants, 100% nonviable pollen was obtained from every flower observed. In T. pseudochamaepitys and T. rotundifolium with rare exceptions, the percentage of nonviable pollen does not seem to be significant.