National Herbarium, established in 1975, is the currently the largest herbarium in Pakistan, located in Islamabad. Dr Ralph Randles Stewart's collection was its initial beginning. At present it has a collection of over 100,000 plants. The plants in the herbarium are divided in to magnoliophytes (dicotyledons and monocotyledons), gymnosperms and pteridophytes (or ferns) and they are placed according to families, genera and species arranged in alphabetical order.