Disease, pest, and deer resistance, heat and drought tolerance, attractiveness to pollinators, and noninvasiveness, make Abelia the ideal landscape plant. Abelia (Caprifoliaceae, Linnaeoideae) is a young genus, and the literature lacks information about reproduction biology, ploidy levels, inheritance of traits, and exploration of new uses for Abelia. The aim of this dissertation is to fill those gaps in the literature. We evaluated self-incompatibility in a full diallel cross among Abelia and Vesalea. Fluorescence microscopy revealed that pollen tube growth was inhibited in the styles, a characteristic of gametophytic self-incompatibility. Trinuclear pollen was identified in Abelia and Diabelia on germinated pollen stained with 0.25 mg∙L-1 DAPI solution. Ploidy levels and genome sizes ranged between 0.89 to 0.95 pg of DNA and 2n=2x=32 for Abelia, Diabelia, and commercial cultivars, and 1.94 and 1.91 pg of DNA and 2n=2x=36 for Vesalea and Zabelia tyaihyonii, when analyzed by flow cytometry. Stomata length and pollen diameter are not indicators of ploidy levels in Linnaeoideae. Yellow leaf color was fitted to a double recessive epistasis model with yellow dominant over green. We propose YG1 and YG2 for these genes, designated YELLOW GREEN LEAF #1 and YELLOW GREEN LEAF #2. Abelia foliage was evaluated for potential use as cut foliage in floriculture. We observed no differences in fresh weight and leaf chlorophyll content of cut Abelia foliage for 9 of the 11 genotypes tested after 8 weeks post-harvest. To improve germination of immature embryos/ovules of hybrids cultured in vitro, gibberellic acid, cold temperatures and dark/light treatment were evaluated on five-week old cultured embryos. These factors had no effect in the germination of embryos of A. ‘Francis Mason’ x A. chinensis. A cold treatment of 4 °reduced germination of A. ‘Francis Mason’ x A. schumanii embryos in vitro, indicating a strong genotypic effect. This is the first report of a gametophytic self-incompatibility system in Abelia and Vesalea, trinuclear pollen in Abelia and Diabelia, total DNA content in Abelia, Diabelia, Vesalea and Zabelia, ploidy levels of A. macrotera var. engleriana and Z. tyaihyonnii var. mosanensis; and inheritance of yellow leaf color in Abelia.