Prospect Park in Brooklyn and the New York Botanical Garden in the Bronx are the recipients of a gift that Mayor Bloomberg is describing as “an unbelievable commitment to our city’s future.”

The founding trustee of the Leon Levy Foundation, Shelby White, announced that her organization would award a total of $25 million in grants, one of the largest private donations to the city’s parks in history.

Mayor Bloomberg, himself one of the largest philanthropists in the country, praised Ms. White for her commitment to charity at yesterday’s announcement in Brooklyn.

Of the grants, $15 million will go toward building a new Native Plant Garden at the New York Botanical Garden, which will showcase plant species indigenous to America. The other $10 million is slated to help fund the completion of Prospect Park’s Lakeside Center, a 26-acre section that will be modeled on the original design of the park’s architects, Frederick Law Olmsted and Calvert Vaux. Part of the Lakeside Center plan includes demolishing the Wollman Rink and replacing it with a pair of new rinks nearby that will host ice- and roller skaters.

Ms. White said yesterday that she chose to give the money to Prospect Park in part due to her Brooklyn roots. “I grew up a block from the park. It was my backyard,” she said, recounting childhood memories of horseback riding and bird-watching there. Also, with an apology to the anti-tobacco Mr. Bloomberg, she said she had smoked her first cigarette there.

Ms. White’s late husband, Leon Levy, amassed a fortune on Wall Street as an investor. He donated hundreds of millions of dollars to charity before his death in 2003 at age 77. The Leon Levy Foundation was created after his death using the money from his estate.