In Laos, Cladophora spp. (ໄຄ [kʰáj] "river weed" or more precisely ໄຄຫີນ [kʰáj hǐːn] "rock river weed") are commonly eaten as a delicacy and usually known in English under the name "Mekong weed". The algae grow on underwater rocks and thrive in clear spots of water in the Mekong river basin. They are harvested 1 to 5 months a year and most often eaten in dry sheets (ໄຄແຜ່ນ [kʰáj pʰɛ̄ːn] kaipen -kháy sheets-), much like Japanese nori, though much cruder in their format. Luang Prabang's speciality is dry khai with sesame, while Vang Vieng is famous for its roasted kháy sheets. They can be eaten in strips as an appetizer or with a meal. Luang Prabang kháy sheets are the most readily available form of Mekong weed and are famous throughout the country and in the neighbouring Isaan, though difficult to find beyond Vientiane. Mekong weed can also be eaten raw, in soups, or cooked as in a Lao amok preparation called ຫມົກໄຄ [mók kʰáj].