Dear Little Kreations at Bargara.
According to Wikipedia: Kokedama (苔玉, in English, literally "moss ball") is a ball of soil, covered with moss, on which an ornamental plant grows. The idea has its origins in Japan, where it is a combination of the nearai 根洗い (literally "root wash," but meaning "no pot") bonsai and kusamono planting styles. Today, Kokedama is very popular in Japanese gardens.
The care instructions suggest to water the plants about once a week. They are said to be idea for indoor locations with not too much direct sunlight.
They're absolutely gorgeous and a wonderful way to brighten a room.