The first and, up till now, the only work by which plants from any part of the Celestial Empire could be identified was Bentham's Flora Hongkongensis published in 1861. This Flora dealt only with the small island of Hongkong on the S.E. coast of China and is now moreover out of date and difficult to obtain, so that it has become more and more desirable, with growing interest in the Chinese flora and with the desire among the Chinese themselves for a scientific knowledge of their own country, to publish without delay some sort of preliminary descriptive Flora of a larger area. Such a work will serve as a stimulus to local botanical enterprise and provide a foundation for the collection of materials for a more complete Flora. During our association in the control of the Botanical and Forestry Department at Hongkong we have fully realised this need and have had the matter kept fresh in our minds by constant enquiries for a work of this kind. We have therefore been induced to prepare the keys and other information set forth in the following pages and have deemed it wise to confine ourselves to Kwangtung and Hongkong and to cast the work on a simple scale which would not take too long to carry out nor be too bulky for convenient use.
We desire to record our thanks to Sir Henry Blake, Governor of Hongkong (1897–1903) and to subsequent Governors who have sanctioned successive measures for the increase of efficiency of the botanical service of the colony and for the exploration of neighbouring portions of the coast, hitherto botanically unknown, to Dr. C.G. Matthew, R.N., and to the late Mrs. Gibbs for their help with the detailed exploration of the Colony and to the Chinese botanical collectors and herbarium assistants for their labours for us in the field and office. Lastly we wish to express our appreciation of the courtesy of the Director of the Royal Botanic Gardens, Kew, in allowing the use of the Kew herbarium and library during the final stages of the work.