Book excerpt: China has about 2,500 species of mosses and has the richest and the most diverse moss flora in the Northern Temperate zone. This number is about 20% of all the mosses currently recognized in the world. Knowledge of the Chinese moss flora, like that of the vascular plant flora, is of importance to the understanding of the underlying dynamics of past plant migrations, vegetational history, and the significance of the local refugia in Asia. Volume 1 treats the families Sphagnaceae, Andreaceae, Archidiaceae, Ditrichaceae, Bryoxiphiaceae, Seligeraceae, Dicranaceae, and the Leucobryaceae.