DIED. LOWELL NESBITT, 59, painter; of natural causes; in New York City. Nesbitt was best known for his huge, popular paintings of flowers, rendered in dramatic close-ups. The artist had planned to leave more than a million dollars to Washington's public Corcoran Gallery, but withdrew the bequest after the museum cancelled a show of photos by his friend Robert Mapplethorpe, including some with homoerotic themes.