What is the word on this seal? Whose seal is this?

The seal is Tian Chengxi, born 56 years ago, and his pen name is Bai Yang, a native of Shaanxi. Famous flower painter, graduated from Xi Academy of Fine Arts, director of China Painters Association, president of Chang 'an Oriental Painting and Calligraphy Institute, president of Shaanxi China Traditional Painting and Calligraphy Institute, and a powerful painter of Chang 'an Oriental Painting and Calligraphy Institute. He is good at flower-and-bird painting and line drawing. In the painting, flowers and birds, color and ink blend, and the shades are appropriate, fresh and natural, and both refined and popular. The overall effect is vivid. His works have participated in many exhibitions at home and abroad and have been exhibited in the United States, Japan and Singapore, and have been widely praised by people in the painting and calligraphy circles.