Assistant botanist Herbarium Bogoriense, Bogor, 1959-1962. Instructor University Hawaii, Honolulu, 1965-1971. Program manager Biotrop, Bogor, 1972-1974.
Senior scientist Herbarium Borgoriense, Bogor, 1974-1978, head, 1978-1984. Program specialist in ecological science United Nations Educational, Jakarta, Indonesia, since 1984. Member commission on ecology International Union for Conservation Nature and Natural Resources, Glands, Switzerland, since 1979, Plant Conservation Advisory Group, International Union for Conservation of Nature and World Wildlife Fund.
Member editorial board Blumea, 1984.