The seven oceans (Saptasamudra) surrounding the seven (Sapta) Islands (Dvipa). The geography as described in the Puranas.
Priyavrata divided the earth into these islands / continents and appointed seven of his ten sons as rulers in the order of their birth. The other three, Kavi, Mahavira, Savana, withdrew to the forest.
Surrounded by the salt water ocean (Lavanasamudra). Ruled by Agnidhra. Named after the rose apple tree, Syzygium cumini. Jambudvipa is the main continent, on it is mount Meru, the Axis Mundi. Agnidhara is the father of King Nabhi.
Surrounded by the sugar cane ocean (Ikshusamudra). Ruled by Idhmajihva. Named after the fig tree, Ficus virens.
Surrounded by the wine/liquor ocean (Surasamudra). Ruled by Yajnabahu. Named after the kapok tree, Bombax ceiba
Surrounded by the Clarified Butter Ocean (Ghritasamudra). Ruled by Hiranyareta. Named after the Kusha Grass, Desmostachya bipinnata.
Surrounded by the yogurt ocean (Dadhisamudra). Ruled by Ghritaprishtha. Named after the heron.
Surrounded by the ocean of milk (Dugdhasamudra). Ruled by Medhatithi. Named after the teak tree, Tectona grandis.
Surrounded by the freshwater ocean (Jalasamudra). Ruled by Vitihotra. Named after the blue lotus, Nelundo nucifera.
See also Vedic Cosmology