Shami Patra is also called as "Vanhipatra". Shami is very dear to Lord Ganesh. Shami leaves are offered to Lord Ganesha in the 21 Patra Puja.- with offer mantra Om Ibhavaktraya namaha, Shami Patram Samarpayami So Shami is offered to Lord Ganesh.Shami Tree also represents goddess Durga.
The Shami Tree is worshiped just like Tulsi plant or Bael Tree by Hindus. Its leaves are used in worship as offerings to God Ganesha, Shiva and Hanuman.
The bad effects of Shani God is also kept away by worshiping Shiva and his avatar Hanuman because for Shani God Shiva is his Guru. If Shiva is pleased by the worship of a person, he will not be affected by Shani. Hanuman worship is also fruitful for this purpose because Shani himself had vowed to Hanuman that whoever worships Hanuman that person will not be affected by the bad eyes of Shani. That is why Hanuman worship on Saturdays are so popular. Both of these Gods, Shiva and Hanuman are worshiped by offering "Shami leaves for this purpose.