Plantae Henryanae. SeamusO'Brien, in China Mother of Gardens, in the Twenty‐First Century, Volume 8 (part 2): 43–619. Published in 2025 by China Forestry Publishing House. ISBN 978–7–5219‐3119‐8

There can be no doubt of the importance of the Irish medico, botanist, dendrologist and forester Augustine Henry (1857–1930) in the exploration of China's flora. Employed from 1881–1900 in the service of the Chinese Imperial Maritime Customs Service, he was posted to several different parts of China, notably Yichang in Hubei (1882–1889), Hainan (1889), Taiwan (1892–1895), Mengzi, Yunnan (1896–1898) and Simao, Yunnan 1898–1900, as well as shorter periods in Shanghai. One of his duties at Yichang was to impose customs duties on materia medica being transported down the Yangtze: these included quantities of medicinal plants, known only by their indigenous names. Keen to know more, in March 1885 he wrote to Joseph Hooker at Kew, offering to collect specimens in exchange for determinations. This was too good an offer to pass up, and Hooker wrote back advising Henry to collect in multiples of ten vouchers for each collection number. The result was extraordinary: 15,862 collection numbers, or 158,620 specimens, representing 5,364 taxa. Any field collector will recognise the immense amount of work this entailed, though Henry was assisted in both collection and management of the specimens by Chinese assistants. Sadly, they are seldom named, but an important member of the team in his second stint in Yunnan was 'Old Ho.' It is the result of this labour that is catalogued in Plantae Henryanae, itself an amazing achievement by Seamus O'Brien, who started working on it in 1999 (pers. comm.), an expression of a life-long interest in Ireland's premier botanist. A previous publication by him is In the Footsteps of Augustine Henry and his Chinese plant collectors (Garden Art Press, 2011). As Curator of the National Botanic Gardens, Kilmacurragh, in County Wicklow, O'Brien also has an active interest in cultivating Chinese plants, and this is a strong feature of the present work. After an introductory essay, the bulk of Plantae Henryanae is a catalogue listing (alphabetically by genus) all the plants known (from a literature review) to have been collected by Henry in China, using current POWO nomenclature. Names used in Henry's day are provided as synonyms, and literature citations of specimens/collections are given. Collections made under Henry numbers are listed by province, location and collection number. This is followed (or not, in the case of more obscure taxa) by an informative discursive paragraph (or several for important species, e.g. Camellia sinensis, found as a wild plant by Ho; Davidia involucrata; Eucommia ulmoides, Henry's collections of which founded both a new genus and family; and the hugely popular garden plant Lilium henryi. The famous hoax specimens, prepared by a collector, e.g. of a Viburnum inflorescence inserted into an Aesculus shoot, which became Actinotinus sinensis Oliv., are covered in the entry for Aesculus chinensis var. wilsonii). These very well-researched paragraphs give notes on the species' medical or cultural use and often its performance in cultivation, frequently (and not inappropriately) with a heavy bias towards its presence in Irish gardens. There are also regular references to the Glasnevin Central China Expeditions in 2002 and 2004, led by the author in Henry's footsteps, which resulted in much new material reaching Irish horticulture. Few plants are illustrated here; the limited number of images show mostly Henry, contemporary botanists and successor collectors. The greatest omission in Plantae Henryanae is that no timeline or itineraries for Henry's activities and collecting are provided, and there is no cross-reference from a list of numbers to the plants, which is such a useful feature in Plantae Wilsonianae. Information about the timeline can be gleaned from In the Footsteps of Augustine Henry, and that richly illustrated work could well be regarded as a companion volume to Plantae Henryanae. There is a smattering of mostly insignificant typos throughout, and frequent variation in letter spacing in plant names caused, it seems, by inappropriate line justification, which is a little irritating. Plantae Henryanae joins the earlier great catalogues of Chinese collections by Western botanists Plantae Delavayanae (Franchet & Delavay, 1899–1900) and Plantae Wilsonianae (ed. C.S. Sargent, 1913–17) as a very long overdue record of work of the greatest of them all. It needs to be in every botanical or horticultural library, institutional or private, and to be consulted regularly by anyone working on Chinese plants. It will find a welcome and very active berth in my own collection. Seamus O'Brien is to be heartily congratulated on this true magnum opus, reaffirming Augustine Henry's presence in the botanical pantheon. Obtaining a copy is, however, not so easy as usual. The volume is available from the publisher, China Forestry Publishing House, but perhaps only through book distributors. Other volumes of the China, Mother of Gardens, in the Twenty-First Century series have been made available on Amazon, and it is to be hoped that this one will soon follow suit. The volume also includes Part 1, a monograph of Davidia involucrata in Chinese by Fu Chengxin and Li Wenhao, and a brief Chinese introduction to Plantae Henryanae by Ye Wen.