He was active in many branches of botany, including anatomy and the taxonomy of seed-producing plants. Among his achievements in this direction, the most notable is the treatise "" ("On the generation and development of the spermatophyte embryo"), which is remarkable for the first account of any value of the development and structure of pollen, along with the confirmation of Giovanni Battista Amici's 1823 discovery of the pollen-tube, the confirmation of Robert Brown's views as to the structure of the unimpregnated ovule (with the introduction of the term "sac embryonnaire", or embryo sac), showing how nearly Brongniart anticipated Amici's subsequent (1846) discovery of the entrance of the pollen-tube into the micropyle, fertilizing the female cell, which then develops into the embryo.