Danish grass, Liliaceae, Ophiopogon japonicus. The commercial ground cover plant "Danish grass" of Ophiopogon japonicus belongs to Ophiopogonidae of Liliaceae, mainly including Ophiopogon japonicus, Ophiopogon japonicus and Ophiopogon japonicus, all of which are perennial evergreen or semi-evergreen herbs. At present, Ophiopogon japonicus is widely used in northern China, especially in Beijing and its surrounding areas. In the late 1990s, there was a kind of plant called Danish grass on the market, which was called by merchants as convenient to sell goods. In the early 1980s, the introduction of Danish grass in Liaoning, Hebei, Beijing, Gansu, Shanxi, Shaanxi, Xinjiang and other places achieved initial success.