Pandanus nuts are the seeds of karuka which grow in the highlands of New Guinea. They are a staple food in the area, and each fruit can contain over one thousand seeds.
Pandanus nuts are fairly long, thin seeds at a couple of inches long. They have a hard shell which can be cracked open by hand to reveal a crunchy white flesh very similar to coconut meat but a bit more oily. It also tastes very similar to coconut but many varieties are very nutty as well. The flesh is eaten raw or cooked, and it is very nutritious. Although botanically it is the seed of the karuka, it is culinarily considered a nut.
The pandanus nut is probably most famous for its unique harvesting language. The Papuans believe that evil spirits will attack the harvesters of karuka, so they developed a coded language to use when harvesting the fruit. They switch out many common words with either new words or words that otherwise have different meanings, in an effort to prevent the spirits from listening in.