Most of the islands are mountainous, some with active volcanos. The vegetation of the small and narrow islands, with their wet climate, is very luxuriant. It includes rainforests, sago, rice, and the famous spices; including nutmeg, cloves, and mace. Though originally Melanesian, the people of many island clans, especially in the Banda Islands, died in the 17th century. A second group of Malay people arrived in the early 20th century under the Dutch and this has continued in the Indonesian era.