The mod generates flower bushes randomly on grass blocks in the world. When destroyed, it will drop 4 flowers and 1-3 seeds. The seeds can then be planted on a grass block. Its growth has four stages, and light level is a factor of it (16.67% of growing per tick under light level 15 (sunlight), you can change it through the configuration file). The first three levels of growth wont drop anything if destroyed, so be careful around your flowers!
Stages of bush growth (from left to right). The last two shows the final stage of rose bush and dandelion bush respectively.