"There are about a dozen of these gardens, more or less extensive, according to the business or wealth of the proprietor; but they are generally smaller than the smallest of our London nurseries."
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Source : Robert Fortune (1847). “Three Years' Wanderings in the Northern Provinces of China: Including a Visit to the Tea, Silk, and Cotton Countries; with an Account of the Agriculture and Horticulture of the Chinese, New Plants, Etc”, p.141