Here was a man of exploit and industry. There was not one continent he did not explore, to bring home seeds, dried specimens and living plants to Kew. He went with Ross to the Antarctic, to the farthermost south, crossing the 78th parallel and battling with icebergs in the world's stormiest ocean; he climbed in the Himalaya to a height of 19,300 feet while the Matterhorn was yet unscaled; he brought home the Sikkim rhododendrons to dazzle the eyes of all who beheld them, opening the book of gardens at a new page.
He it was who helped Charles Darwin, encouraging him to put his ideas down on paper – ideas which shook the world. He kept Darwin's theory of evolution secret for fifteen years until the Origin of Species was published. He himself was the acknowledged authority on ‘that almost keystone of the laws of creation’, the geographical distribution of plants.
Thus wrote Mea Allan in her book The Hookers of Kew, introducing Sir Joseph Dalton Hooker (1817–1911). The son of Sir William Jackson Hooker (the first Director of the Royal Botanic Gardens, Kew), Joseph succeeded his father as the second Director in 1865, having served under him as Assistant Director from 1855. Joseph, in turn, was succeeded by his son-in-law, Sir William Thiselton-Dyer. Together, these three represent a dynasty that held the reins of power at Kew from 1841 to 1905. One of their successors, Sir George Taylor (Director of Kew, 1956–1971), stated that ‘At Kew their [the Hookers'] names are revered beyond all others and their influence will always pervade the Gardens and is an inspiration to all associated with Kew’ (quoted in Allan, 1967). Much has been written about Joseph Hooker, and the reader interested in fuller details than those provided here is referred to other sources including Allan's classic book and the excellent website (http://www.jdhooker.org.uk/) run by J. Endersby.
In December 2011 the centenary of the death of Joseph Hooker will be marked by a meeting, organised by the Linnean Society, Kew, the Kew Guild and the University of Sussex, and a special exhibition about his life and work, both at Kew. Indicative of the continuing interest in Hooker's work, the meeting at Kew was fully booked several weeks before the event. One of the most influential botanists and scientists of the 19th Century, in addition to being Director of Kew from 1865 to 1885, he was President of the Royal Society from 1873 to 1878. He had a long association with the Linnean Society, being elected a Fellow in 1844 and receiving the Linnean Medal in 1888 (on the first occasion that this was presented) and the Darwin-Wallace Medal of the Society in 1908 (on the first occasion that it was presented; one of the other recipients being none other than Alfred Russel Wallace, after whom the medal was co-named).
In his Hooker lecture presented at the Linnean Society in 2008, Professor Sam Berry (a Past President of the Linnean Society) recalled the strong link between Darwin and Hooker and their shared interest in islands:
Following Hooker's return from the voyage around the Antarctic, he was retained on half-pay to write an Antarctic flora. Meanwhile, Darwin (having failed to get Henslow to work on the plant material that he had brought back from the Beagle) wrote to William Hooker in 1843 to seek help. Thus Darwin made contact with [Joseph] Hooker. Their correspondence shows that by January 1844 Darwin was discussing his ideas on the “way by which species become exquisitely adapted to various ends” with island populations playing a significant role in development of the theory. (Paraphrased from the summary of the lecture on the Linnean Society webpages: http://linnean.org/; see also Berry, 2009a, b)
Hooker became a close friend and confidant of Darwin; he read Darwin's unpublished manuscript on species as early as 1844, but did not reveal its contents until the meeting in 1858 at which the papers by Darwin and Wallace were read (Gardiner, 2002; Fay, Christenhusz & Chase, 2010). A detailed account of that meeting was provided by Moody (1971). Darwin and Hooker exchanged many letters from the 1840s to the 1880s (see the Darwin Correspondence Project: http://www.darwinproject.ac.uk/), and, in addition to islands (e.g. Carlquist, 2009; Porter, Murrell & Parker, 2009; Simbaña & Tye, 2009), they shared many botanical interests including carnivorous plants (e.g. Chase et al., 2009) and orchids (e.g. Micheneau et al., 2009). Other notable scientific friends and colleagues were Charles Lyell, Thomas Huxley and George Bentham. Bentham and Hooker had an active and highly productive collaboration, including their three-volume Genera Plantarum (Bentham & Hooker, 1862–1883), leading to the eponymous and widely used Bentham & Hooker system of plant classification. This was, for example, the basis for the arrangement of the Order Beds at Kew until they were recently reorganised to follow the Angiosperm Phylogeny Group classification (APG III, 2009).
Hooker, like his father before him, was a prolific author. In addition to numerous books, he also published a large number of scientific papers, including many published in the journals of the Linnean Society. In addition to floristic studies concerning Africa, Asia and islands in the southern oceans, these covered taxa in a wide range of angiosperm families (e.g. Ancistrocladaceae, Apocynaceae, Balanophoraceae, Balsaminaceae, Clusiaceae, Fagaceae, Moraceae, Myrtaceae, Nepenthaceae and Rhamnaceae), gymnosperms and even algae. A search for ‘Hook.f.’ (the standard form of his name for use with taxa he described) in the International Plant Names Index (http://www.ipni.org) reveals that he was also amazingly prolific in his descriptions of new taxa: 12 722 names in families from Acanthaceae to Zygophyllaceae are found in the resulting list! Maybe one of his most famous new taxa is the gymnosperm Welwitschia mirabilis; both the genus and the species bear his name as author. The highly detailed paper including 14 plates, illustrating the habit, morphology and anatomy of this extraordinary plant, is a classic (Hooker, 1862); Plate 1 is reproduced here. In a piece on Hooker in The Linnean (Anon, 1997), it is reported that:
Hooker later regarded his description of W. mirabilis as a triumph in comparative anatomy – Asa Gray called it “the most wonderful discovery (in a botanical point of view) of the century”.
Publications in recent issues of the Botanical Journal of the Linnean Society contain many references to the publications of Hooker. These include articles relating to the angiosperm families Apiaceae (Degtjareva et al., 2009), Bromeliaceae (De Faria, Wendt & Brown, 2010), Combretaceae (Maurin et al., 2010), Commelinaceae (Cabezas et al., 2009), Fabaceae (Cusma-Velari & Feoli-Chiapella, 2009; Lackey, 2009), Gunneraceae (González & Bello, 2009), Hydrangeaceae (Liu & Zhu, 2011), Lamiaceae (Bramley, 2009; Wang & Hong, 2011), Liliaceae (Wang et al., 2009), Linaceae (Simbaña & Tye, 2009; McDill & Simpson, 2011), Melastomataceae (Reginato, Michelangeli & Goldenberg, 2010), Nepenthaceae (Chase et al., 2009), Orchidaceae (Micheneau et al., 2009; Pupulin, 2010; Adams, 2011), Poaceae (Sun et al., 2010), Ranunculaceae (Ehrendorfer et al., 2009), Rosaceae (Chin et al., 2010) and Sarraceniaceae (Chase et al., 2009), gymnosperms (Gnetales; Rydin, Khodabandeh & Endress, 2010) and bryophytes (Wilbraham, 2010). The number and wide taxonomic coverage of these articles clearly demonstrate the ongoing significance of his scientific legacy.
Joseph Dalton Hooker was indeed a great Linnean.