Recently, tasks asking for floral formulas and diagrams appear more often in olympiads.
Below you will find some notes on flowers:
http://faculty.etsu.edu/liuc/Lecture%2024.%20Flower-contd.pdf
Here you will find digital flower website.
All you need to know about flowers and inflorescences: https://uqu.edu.sa/files2/tiny_mce/plugins/filemanager/files/4290002/Lecture%208.pdf.
