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Hooker, Joseph Dalton

Hooker, Joseph Dalton

(b. Halesworth, England, 30 June 1817; d. Sunningdale, England, 10 December 1911)

botany.

Hooker was the second child of the botanist Sir William Jackson Hooker and Maria Sarah Turner. Glasgow High School provided him with a traditional Scottish liberal education which was broadened by his own leisure-time interest in botany and entomology. He studied medicine at Glasgow University, receiving an M.D. in 1839. His father’s influence was predominant in his life; to him he owed his physical stamina, his capacity for sustained hard work, his artistic ability, and the opportunity to fulfill his youthful ambitions of becoming a great botanist and traveler.

Hooker ultimately achieved great professional eminence and many academic honors were bestowed on him. Elected a fellow of the Royal Society in 1847, he served as president of the society from 1873 to 1878 and made notable improvements in its organization and financial resources. During celebrations in 1907 to mark the bicentenary of Linnaeus’ birth, the Swedish Academy of Sciences awarded him the single, specially struck Linnean Medal as “the most illustrious living exponent of botanical science.” He was created C.B. in 1869 and Knight Commander of the Order of the Star of India in 1877.

Hooker was blessed with two happy marriages. In 1851 he married Frances Harriet Henslow, the eldest daughter of the Reverend John Stevens Henslow. There were six surviving children on her death in 1874. In 1876 he married Hyacinth, the only daughter of the Reverend William Samuel Symonds, and the widow of Sir William Jardine. He had two children by this second marriage.

Hooker’s descriptions of three new Indian mosses, his first contributions to scientific literature, were published in his father’s periodical, Icones plantarum, in 1837. His father’s position and influence obtained for him the post of assistant surgeon and naturalist on H.M.S. Erebus, which, with H.M.S. Terror, had among its exploratory goals a determination of the position of the south magnetic pole. Under the command of Captain James Clark Ross the expedition left England in September 1839 and did not return until September 1843. The voyage encompassed the exploration of the Great Ice Barrier and of several oceanic islands, including the Falklands, Tasmania, and New Zealand.

Much of the botanical material collected on the Erebus voyage came from territory never before explored, and doubtless fostered in Hooker an enduring interest in taxonomy and plant geography. The results of his botanical investigations, carefully and judiciously compiled, were eventually published in Flora Antarctica (1844–1847), Flora Novae-Zelandiae (1853–1855) and Flora Tasmaniae (1855–1860). Known collectively under the title The Botany of the Antarctic Voyage of H. M. Discovery Ships ’Erebus’ and ‘Terror’ this great work in six quarto volumes established Hooker as a leading world botanist. Thoroughness and accuracy characterize his full Latin descriptions and detailed taxonomic notes in English. The excellent accompanying lithographs, by W. H. Fitch, were based on Hooker’s field sketches and specimens. The work appeared at a critical period in biology, and the introductory essays to the Flora Novae-Zelandiae and Flora Tasmaniae, published in 1853 and 1860 respectively, are valuable indexes of the uncertainty in scientific thought at the time of the publication of Darwin’s Origin of Species (1859). Hooker’s attention was especially drawn to the taxonomic resemblances between the floras of South America, the subantarctic islands, New Zealand, and Australia. He sought to explain these similarities largely by a land bridge theory—postulating a lost circumpolar continent—and rejected Darwin’s alternative hypothesis of the transport of seeds by ocean currents, winds, and birds.

In the autumn of 1843 Hooker settled with his parents at Kew, where he had access to his father’s extensive herbarium and library for working out the botanical results of his Antarctic voyage. In 1845 he gave a series of botanical lectures at Edinburgh University, presumably to advance his candidature for the professorship of botany pending the death of Robert Graham, who was seriously ill. Unsuccessful in his application for the post, he accepted in February 1846 an appointment as a paleobotanist with the Geological Survey—he had earlier manifested an interest in paleobotany when he published a paper on certain Tasmanian fossil woods. His first official assignment was to prepare a catalogue of British fossil plants for an arrangement of specimens in the Geological Survey museum. He wrote many papers on fossil botany until his appointment as assistant director at the Royal Botanic Gardens, Kew, in 1855, after which the subject ceased to occupy his attention.

In 1854 Hooker wrote to Darwin:

From my earliest childhood I nourished and cherished the desire to make a creditable journey in a new country, and write such a respectable account of its natural features as should give me a niche amongst the scientific explorers of the globe I inhabit, and hand my name down as a useful contributor of original matter.1

This ambition had been realized when Hooker embarked for India in November 1847. With a Treasury grant and a commission in the Royal Navy, he spent three years in northeast India, mainly in the Himalayan state of Sikkim and in eastern Nepal, engaged in botanical exploration and topographical surveying. For most of his stay in India he traveled alone, but in October 1849 he was joined by Dr. Archibald Campbell, the superintendent of Darjeeling and political agent to Sikkim. Both were arrested and imprisoned for several weeks by the Sikkim authorities.

Hooker was practically the first explorer of the eastern Himalaya since Turner’s embassy to Tibet in 1789. Not only did he add much to the existing knowledge of the Indian flora but he also made detailed meteorological and geological observations, while his accurate survey work on the complex mountain terrain formed the basis of a map published by the India Trigonometrical Survey. Horticulturalists will always associate Hooker’s name with the genus Rhododendron because he introduced a number of new species into cultivation in England. While Hooker was still in India, his father supervised the publication in 1849 of the first part of his son’s Rhododendrons of Sikkim-Himalaya, embellished with superb color lithographs by Fitch, prepared from Hooker’s sketches and dried specimens.

In 1850 he traveled in the Khasi Mountains of Assam with Thomas Thomson, a friend from his school days, with whom he collaborated on the onevolume Flora Indica (1855); Hooker’s introductory essay to this book, containing an admirable account of the history of botany in India and the geographical distribution of the flora, was to form the basis of his masterly “Sketch of the Flora of British India” in the Imperial Gazetteer of India (1907). Assisted by other botanists, Hooker produced the Flora of British India (1872–1897) in seven volumes to replace the Flora Indica. This still remains a classic account in English of families, genera, and species of all Indian seedbearing plants. It has served as a foundation for a number of regional Indian floras, but although it is inevitably in need of present-day revision, no up-to-date flora of the Indian subcontinent has yet replaced it. On the completion of this great undertaking Hooker, who had been made a knight commander of the Order of the Star of India in 1877, was made a grand commander of the order.

Hooker later wrote volumes IV and V (1898–1900) of A Handbook to the Flora of Ceylon, which had been left unfinished in 1896 on the death of its author, H. Trimen. During his researches on the Indian flora, Hooker became aware of the need for a taxonomic revision of the genus Impatiens. His last years were occupied with an intensive investigation of this genus, of which he described more than 300 species as being new.

There remains one book associated with Hooker’s work in India which has an appeal for the nonbotanist, namely his Himalayan Journals (1854). It is a record of adventure and scientific observation, lucidly and modestly related, entirely deserving its place as a minor classic of nineteenth-century travel literature. It was dedicated to Charles Darwin.

Hooker met Darwin briefly for the first time in 1839 and within a few years they had become close friends. On 11 January 1844 Darwin confided to Hooker the direction of his thinking: “At last gleams of light have come, and I am almost convinced that species are not (it is like confessing a murder) immutable:—I think I have found (here’s presumption!) the simple way by which species become exquisitely accepted to various ends.”2 For many years Hooker was kept informed of Darwin’s gradual progression from tentative hypothesis to confident belief. In a letter to W. H. Harvey, written about 1860, Hooker wrote, “I was aware of Darwin’s views fourteen years before I adopted them and I have done so solely and entirely from an independent study of the plants themselves.”3 Hooker gradually came to accept the theory of evolution on the basis of his own taxonomic work and researches on the geographical distribution of plants.

Until his introductory essay (1860) for the Flora Tasmaniae, however, there is in Hooker’s published works no clear confirmation of Darwin’s influence. In the introductory essay (1853) to the flora Novae-Zelandiae Hooker tentatively advocated the permanency of species as an essential requirement for practical taxonomy. The introduction to the Flora Indica (1855) shows Hooker as still recognizing species as “being definite creations” but as “created with a certain degree of variability.”4 A review by Hooker in Hooker’s Kew Journal of Botany (1856) of Alphonse de Candolle’s Géographie botanique raisonnée (1855) revealed an ambivalence in his position. He asserted here that there was no proof for Candolle’s belief “that the majority of species were created such as they now exist”; and he agreed that the “theory of transmutation [of species] accounts better for the aggregation of Species, Genera and Natural Orders in geographical areas, and for their limitation.” But doubt still persisted, for he continued: “...unfortunately transmutation brings us no nearer the origin of species, except the doctrine of progressive development be also allowed and, as we can show, the study of plants affords much positive evidence against progressive development, and none in favour of it.”5 In 1858 Hooker and the geologist Lyell were instrumental in persuading both Darwin and Alfred Russel Wallace to agree to a joint presentation of their papers on evolutionary theory to the Linnean Society of London.

Soon after the publication of the Origin of Species in 1859 Hooker became a decided advocate of Darwinism, but he reached this position only after his own careful and prolonged assessment of all available scientific evidence. In his introductory essay (1860) to the Flora Tasmaniae he cautiously accepts the theory of evolution and natural selection. His characteristic consideration and questioning of all aspects of a problem once prompted Darwin to refer to him as “you terrible worrier of poor theorists.”6

Hooker’s eventual adherence to Darwinism came partly through the persuasions of his own phytogeographical evidence. He was one of the first botanists to offer the mutability and derivative origins of species as an explanation for the geographical distribution of plants. He was especially attracted by the similarities in the floras of widely separated regions. At first he accepted the geological theories of Lyell and Edward Forbes to explain resemblances in the flora of different Antarctic islands. Much later, however, in a lecture in 1866 to the British Association, On Insular Floras, he conceded that Darwin’s alternative proposition of transoceanic migration offered a rational explanation; the present-day theories of continental drift were not then known. In his classic monograph, Outlines of the Distribution of Arctic Plants (1862), he sought to show that the vegetation of Scandinavia had migrated through Asia and America. His paper to the British Association at York in 1881 summarized his final conclusions on the geographical distribution of plants.

Hooker was appointed assistant director at the Royal Botanic Gardens in 1855, and succeeded his father as director in 1865. During his term of office Sir William Hooker had transformed the moribund gardens, formerly the private property of the British monarch. The grounds were relandscaped, new glasshouses (including the great palm house) were erected, an herbarium and library were formed, and museums of economic botany established. Hooker continued his father’s program of improving the gardens: some additional avenues and walks were introduced, the rock garden was created in 1882, more glasshouses were added, and improvements were made in the water supply. The arboretum was enlarged, an improvement which included the planting of the pinetum in 1871–1872. In 1882 the Marianne North Gallery was opened for the permanent display of the botanical paintings of that indefatigable artist and traveler.

Under Hooker. Kew became an international center for botanical research. The Jodrell Laboratory, a private benefaction of his friend T. J. Phillips Jodrell, was originally built in Kew Gardens as a center for the investigation of the structure and physiology of plants. Since its foundation in 1876 many distinguished botanists have worked there. When Sir William Hooker died in 1865, he left at the Royal Botanic Gardens the nucleus of an official herbarium and library with a wish that his own vast personal collections should be added. These were purchased in 1867 and many important herbaria were added during Joseph Hooker’s directorship: R. Wight’s Indian plants, the mycological herbarium of the Reverend M. J. Berkeley, the mosses of W. P. Schimper, and the lichens of the Reverend W. A. Leighton. An extension to the Kew herbarium soon became necessary and the first wing was added to the building in 1877.

The links which Sir Joseph Banks had established between Kew and the British Empire were strengthened by both Sir William and Sir Joseph Hooker. of particular help to the developing colonies were the consignments of economically useful plants first propagated at Kew. Rubber seedlings, which had originally been smuggled out of Brazil, were sent in 1876 from Kew to Ceylon where they were to become the foundation of the rubber industry of that island and later of the Malay Peninsula. The cultivation of ipecac in India was established in 1866–1867 from Kew material, and Liberian coffee plants and the West African oil palm were distributed to many plantations abroad. Hooker also added to the series of published Kew colonial floras initiated by his father.

It could be argued that Hooker’s greatest service to mankind was his administration of Kew Gardens from 1865 until his retirement in 1885. The Royal Botanic Gardens are very much the creation of the two Hookers, whose energy, foresight, and organizational ability laid such firm and enduring foundations.

Joseph Hooker and the botanist George Bentham, a permanent visitor in the Kew herbarium, recognized the need for a new plant classification to replace the outdated ones of Endlicher and Meissner. Both men were well qualified to undertake such a formidable task. Their collaboration began in 1857 but unfortunately Hooker’s official duties prevented him from contributing more than a third of the final work. The meticulous descriptions of the families and genera of seed-bearing plants, with full synonymy and geographical distribution, were based largely upon direct observation of the rich resources of Kew and its herbarium. The Bentham-Hooker classification, although not a phylogenetic system, is a natural one following, with modifications, the sequence of families proposed by Augustin-Pyramus de Candolle in 1819. The threevolume Genera plantarum (1862–1883) still remains a standard work and its Latin diagnoses are models of accuracy, clarity, and completeness.

The Genera plantarum was one of the many works abstracted by the Index Kewensis (1892 to date), an indispensable index of validly published names of flowering plants. This index owed its inception to a suggestion from Darwin for a complete list of scientific plant names, and Darwin generously helped with the cost of production of the original volumes. Work started on it in 1882 under the supervision of Joseph Hooker, for whom it was claimed that he read all the proofs containing some 380,000 specific names.

In 1870 appeared Hooker’s Student’s Flora of the British Isles, which aimed at presenting fuller information on vascular plants than that provided by existing manuals. Further editions appeared in 1878 and 1884. Hooker edited the fifth through the eighth editions (1887–1908) of G. Bentham’s Handbook of the British Flora. He also edited two well-known botanical periodicals: Botanical Magazine from 1865 to 1904, writing many of the plant descriptions himself; and Hooker’s Icones plantarum, founded by his father in 1836. For the latter periodical he edited volumes 11 to 19 (1867–1890), which were illustrated with many of his own line drawings.

His exacting duties as director at Kew Gardens did not prevent Hooker from participating in further botanical excursions abroad. In the autumn of 1860 he and Daniel Hanbury spent about two months in Palestine and Syria, where Hooker examined the history, position, and age of the famous cedar grove on Mount Lebanon. He regarded the three species of cedar found in the Himalaya, Syria, and Africa as geographical forms of one species. He contributed an account of the botany of Syria and Palestine to volume II of W. Smith’s Dictionary of the Bible (1863).

From April to June 1871 Hooker, in the company of John Ball and George Maw, explored Morocco. The subsequent account of their journey was written mainly by Ball, but Hooker contributed the first two chapters and three valuable appendices in which he compared the flora of the Canaries and Morocco. An important discovery of the expedition was that the Arctic-Alpine flora did not reach the Atlas Mountains.

In 1871 Hooker joined his friend Asa Gray in western North America in what was to be his last major botanical expedition. Both botanists were interested in the floristic similarities of the eastern United States and eastern continental Asia and Japan. Hooker was of the opinion that the Miocene flora in western North America had been eliminated by glaciation, but that such flora had managed to survive on the eastern side of the continent and in eastern Asia.

Hooker proved himself to be highly competent in a number of botanical disciplines, but he distinguished himself most notably in taxonomy and plant geography, areas which also provided him with the evidence that made him an evolutionist. In pure morphology he will be remembered for his classic papers on Balanophoreae (1856), Nepenthes (1859), and Welwitschia (1863). His reasoning was instinctively inductive; he was always reluctant to commit himself to any generalization before he had examined all the available facts and tested them against his exceptionally wide experience and knowledge.

NOTES

1. F. Darwin, More Letters of Charles Darwin, I (1903), 70.

2. F. Darwin, Life and Letters of Charles Darwin, II (1887), 23.

3. L. Huxley, Life and Letters of Sir Joseph Dalton Hooker, I (1918), 520.

4. J. Hooker, Introduction to Flora Indica (1855), 20.

5. J. Hooker, “Géographie botanique raisonnee... par M. Alph. de Candolle; a Review,” in Hooker’s Kew Journal of Botany, 8 (1856), 252.

6. F. Darwin, More Letters of Charles Darwin, I (1903), 105.

BIBLIOGRAPHY

I. Original Works. Hooker’s writings include The Botany of the Antarctic Voyage of H. M. Discovery Ships ‘Erebus’ and ‘Terror’ in the years 1839–1843 Under the Command of Captain Sir James Clark Ross: pt. 1, Flora Antarctica, 2 vols. (London, 1844–1847); pt. 2, Flora Novae-Zelandiae, 2 vols. (London, 1853–1855); pt. 3, Flora Tasmaniae, 2 vols. (London, 1855–1860); Rhododendrons of the Sikkim-Himalaya (London, 1849–1851); Himalayan Journals (London, 1854); Flora Indica (London, 1855), written with T. Thomson; Illustrations of Himalayan Plants (London, 1855); “Géographie botanique raisonnee... par M. Alph. de Candolle; a Review,” in Hooker’s Kew Journal of Botany, 8 (1856), 54–64, 82–88, 112–121, 151–157, 181–191, 214–219, 248–256; Genera plantarum, 3 vols. (London, 1862–1883), written with G. Bentham; Handbook of the New Zealand Flora (London, 1864–1867); Student’s Flora of the British Islands (London, 1870); Flora of British India, 7 vols. (London, 1872–1897); and “Sketch of the Flora of British India,” in Imperial Gazetteer of India, 3rd ed., I (1907), 157–212.

II. Secondary Literature. See L. Huxley, Life and Letters of Sir Joseph Hooker, 2 vols. (London, 1918); W. B. Turrill, Joseph Dalton Hooker (London, 1964); and Mea Allan, The Hookers of Kew, 1785–1911 (London, 1967).

R. Desmond

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Hooker, Sir Joseph Dalton

Hooker, Sir Joseph Dalton (1817–1911) A British botanist, who graduated in medicine at the University of Glasgow in 1839 and was then appointed assistant surgeon on board the Erebus, as a member of the Antarctic expedition led by Sir James Ross. On his return, in 1843, he published Flora Antarctica (1844–7), Flora Novae Zelandiae (1853–5), and Flora Tasmanica (1855–60). He explored the northern frontiers of India (1847–51), and published the Flora of British India (1855–97). The large number of rhododendrons he brought from India became popular ornamentals, transforming many British gardens. He prepared the fifth and sixth editions of Bentham's Handbook of the British Flora, which then became known to generations of students as ‘Bentham and Hooker’. He was appointed assistant director of the Royal Botanic Gardens at Kew in 1855 and succeeded his father as director in 1865.

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Hooker, Joseph Dalton

Hooker, Joseph Dalton

British Botanist 1817-1911

Joseph Dalton Hooker was one of the leading British botanists of the late nineteenth century. He was born in Halesworth, Sussex, and was the son of another great British botanist, Sir William Jackson Hooker (1785-1865). Hooker graduated with a degree in medicine from Glasgow University, where his father was a professor of botany. His father eventually held the position of Director of Kew Gardens in London and, through his leadership, made it one of the finest botanical gardens in the world, with an extensive collection of plants from the British colonies. In 1855 Joseph Hooker became assistant director of Kew Garden and became director when his father died in 1865.

Hooker is best known for his work in taxonomy, the science of classification, and plant geography, the science of plant distribution. These primary interests were shaped by his participation in a famous four-year scientific expedition under the command of Captain James Clark Ross that sought to determine the position of the south magnetic pole. Hooker was aboard the H.M.S. Erebus, one of the two expeditionary ships that left England in 1839. Although he was appointed the ship's assistant surgeon, Hooker made extensive collections of botanical material from geographic regions not previously explored, including the Great Ice Barrier and several oceanic islands such as Tasmania, the Falklands, and New Zealand. Hooker was struck by the similarity of the floras of these regions. He explained these similarities by adopting a land-bridge theory, one that postulated the existence of a lost circumpolar continent. It was on the basis of these observations that Hooker began to adopt an evolutionary explanation for the similarities. His work was summarized in a collection known as The Botany of the Antarctic Voyage of H.M. Discovery Ships Erebus and Terror. The publication of its six quarto volumes between 1853 and 1855 established Hooker as one of the great botanists of the nineteenth century.

Hooker continued to travel and explore through much of his life, and in the process compiled many floras. He also collected many plant specimens, which he introduced to England. He is especially well known for his stunning, previously unknown species of Rhododendron that he discovered in the Sikkim region of the Himalayas. Many of these are still grown in Kew Gardens. He also made notable contributions in pure morphology, including classic studies on the unusual plant Welwitschia (1863).

Hooker is also known for his close friendship with the most famous naturalist of his day, Charles Darwin (1809-1882). In fact, Darwin trusted Hooker enough to confide his radical new theory of descent with modification by means of natural selection (later called evolution by means of natural selection) in 1844, some fifteen years before Darwin wrote On the Origin of Species (1859). Although Hooker knew of this theory well in advance of its publication, he was not convinced of its importance until his own observations of the distribution of plants were completed. Darwin and Hooker remained close friends until Darwin's death. Hooker led a long and productive life and was knighted in 1877. He died in Sunningdale, England, in 1911.

see also Biogeography; Botanical Gardens and Arboreta; Curator of a Botanical Garden; Darwin, Charles; Taxonomist; Taxonomy.

Vassiliki Betty Smocovitis

Bibliography

Allen, M. The Hookers of Kew, 1785-1911. London: Michael Joseph, 1967.

Desmond, R. "Joseph Hooker." In Dictionary of Scientific Biography, Vol. 6. New York: Scribner's Sons, 1970.

Huxley, Leonard. Life and Letters of Sir Joseph Dalton Hooker. London: John Murray, 1918.

Turrill, William Bertram. Joseph Dalton Hooker. London: Thomas Nelson and Sons Ltd., 1964.

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Hooker, Sir Joseph Dalton

Hooker, Sir Joseph Dalton (1817–1911) A British botanist, who in 1865 succeeded his father, Sir William Jackson Hooker, as director of the Royal Botanic Gardens, at Kew, London. He was a friend and champion of Charles Darwin, who relied greatly on Hooker's botanical knowledge in his books on evolution.

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