Embryological features of the two tetraploid species ofDentella-Dentella repens andDentella serpyllifolia are essentially identical. Anther wall development follows the Dicotyledonous type. Secretory tapetum is uniseriate with unir-uckate cells. Female archesporium is single-celled. Embryo sac development follows the Polygonum type. Endosperm is nuclear. Embryogeny conforms to Hyoscyamus variation of Solanad type. Seed coat is formed by the outer epidermis of the integument.