What is Agathis?
Agathis is the name for a genus of giant tropical conifer trees found in rain forests in the tropical far east and the southwest Pacific. The genus is a member of the Araucariaceae, the plant family which includes the monkey-puzzles and Cook-pines as well as the recently discovered Wollemi Pine, a botanical "living fossil" from New South Wales in Australia. The Araucariaceae belongs to a group of plants known as the conifers, which also includes the pine family (pines, spruces, larches, firs, cedars), the podocarp family (podocarps, kahikatea, totara, etc.) and the cypress family (swamp-cypresses, giant sequoias, junipers & cypresses). The timber is immensely useful (see below) and is increasingly used, or so it would seem, for making guitars.
Where does Agathis come from?
Agathis grows in rain forests right across southeast Asia and the western Pacific, from Malaysia in the west through Indonesia, Brunei, the Phillippines, and Papua New Guinea to Australia (Queensland), New Zealand (northern North Island), the Santa Cruz group of the Solomon Islands, Vanuatu, New Caledonia and Fiji in the east. A little map is available below: the shaded areas indicate parts of the world within which stands of the tree may be found, rather than vast forests of the trees. Where most of the wood being used in guitar-making comes from I do not know, but it seems unlikely to be New Zealand