You can definitely check out the link below. Which is given as it contains in the specific notes for the botany section. you can definitely check out the NCERT textbook as they are the base of the class 11 and 12 Biology And their offer excellent understanding of the topics.The plant Kingdom topic covers the classification of plants into various groups based on the characteristics like reproduction structure evolution, etc. You can check out the given link below for more detailed information the sexual reproduction in flowering plants  topic  focuses on the process of sexual reproduction  OF flowering plant.

pLANT KINGDOM

BOTANY