DOVER, Del. - Polly Hill, a horticulturist who helped develop standards for record-keeping in botanical gardens nationwide, died April 25. She was 100.

Hill, who founded an arboretum on Martha's Vineyard off Massachusetts that bears her name, died of heart failure at her home in Hockessin, according to her son Joseph.

Born Mary Louisa Butcher in Ardmore, Pa., Hill became known internationally for her skill in growing hardy trees and shrubs from seed, something she began in her 50s.

Known since childhood as Polly, she attended the Phoebe Anna Thorne Open-Air School for Girls of Bryn Mawr College and later graduated from Agnes Irwin School and Vassar College, where she majored in music.

She studied botany and horticulture at the University of Delaware and at Longwood Gardens near Wilmington. While studying at Longwood Gardens, she served on a committee that developed standards for record-keeping in botanic gardens throughout the country.

By 1997, when Hill was 90, her garden contained about 1,700 different kinds of woody plants. The property was renamed The Polly Hill Arboretum and established as a nonprofit organization for research and education. *