Banksia Sessilis - Discovery and Naming

Discovery and Naming

Specimens of B. sessilis were first collected by Scottish surgeon Archibald Menzies during the visit of the Vancouver Expedition to King George Sound in September and October 1791. No firm location or collection date can be ascribed to Menzies' specimens, as their labels simply read "New Holland, King Georges Sound, Mr. Arch. Menzies", and Menzies' journal indicates that he collected over a wide area, visiting a different location every day from 29 September to 8 October. In addition to B. sessilis, Menzies collected plant material of B. pellaeifolia, and seeds of at least four more Banksia species. This was therefore an important early collection for the genus, only seven species of which had previously been collected.

Menzies' seed specimens were sent to England from Sydney in 1793, but his plant material remained with him for the duration of the voyage, during which some material was lost. On his return to England in 1795, the surviving specimens were deposited into the herbarium of Sir Joseph Banks, where they lay undescribed for many years.

The next collection was made in December 1801, when King George Sound was visited by HMS Investigator under the command of Matthew Flinders. On board were botanist Robert Brown, botanical artist Ferdinand Bauer, and gardener Peter Good. All three men gathered material for Brown's specimen collection, including specimens of B. sessilis, although neither Brown's nor Good's diary can be used to assign a precise location or date for their discovery of the species. Good also made a separate seed collection, which included B. sessilis, and the species was drawn by Bauer. Like nearly all of his field drawings of Proteaceae, Bauer's original field sketch of B. sessilis was destroyed in a Hofburg fire in 1945. A painting based on the drawing survives, however, at the Natural History Museum in London.

On returning to England in 1805, Brown began preparing an account of his Australian plant specimens. In September 1808, with Brown's account still far from finished, Swedish botanist Jonas Dryander asked him to prepare a separate paper on the Proteaceae, so that he could use the genera erected by Brown in a new edition of Hortus Kewensis. Brown immediately began a study of the Proteaceae, and in January 1809 he read to the Linnean Society of London a monograph on the family entitled On the Proteaceae of Jussieu. Among the eighteen new genera presented was one that Brown named Josephia in honour of Banks.

Brown's paper was approved for printing in May 1809, but did not appear in print until March the following year. In the meantime, Joseph Knight published On the cultivation of the plants belonging to the natural order of Proteeae, which appeared to draw heavily on Brown's unpublished material, without permission, and in most cases without attribution. It contained the first publication of Brown's Josephia, for which two species were listed. The first, Josephia sessilis, was based on one of Menzies' specimens: "This species, discovered by Mr. A. Menzies on the West coast of New Holland, is not unlike some varieties of Ilex Aquifolium, and now in his Majesty's collection at Kew." The etymology of the specific epithet was not explicitly stated, but it is universally accepted that it comes from the Latin sessilis (sessile, stalkless), in reference to the sessile leaves of this species. Blame for the alleged plagiarism largely fell on Richard Salisbury, who had been present at Brown's readings and is thought to have provided much of the material for Knight's book. Salisbury was ostracized by the botanical community, which undertook to ignore his work as much as possible. By the time Brown's monograph appeared in print, Brown had exchanged the generic name Josephia for Dryandra, giving the name Dryandra floribunda to Knight's Josephia sessilis. As there were then no firm rules pertaining to priority of publication, Brown's name was accepted, and remained the current name for over a century.

Another significant early collection was the apparent discovery of the species at the Swan River in 1827. In that year, the colonial botanist of New South Wales Charles Fraser visited the area as part of an exploring expedition under James Stirling. Among the plants that Fraser found growing on the south side of the river entrance was "a beautiful species of Dryandra", which was probably this species.

Over the course of the 19th century, the principle of priority in naming gradually came to be accepted by botanists, as did the need for a mechanism by which names in current usage could be conserved against archaic or obscure prior names. By the 1920s, Dryandra R.Br. was effectively conserved against Josephia Knight, although a mechanism for formal conservation was not put in place until 1933. Brown's specific name, however, was not conserved, and Karel Domin overturned Dryandra floribunda R.Br. by transferring Knight's name into Dryandra as Dryandra sessilis (Knight) Domin in 1924. This name was current until 2007, when all Dryandra species were transferred into Banksia by Austin Mast and Kevin Thiele. The full citation for the current name is thus Banksia sessilis (Knight) A.R.Mast & K.R.Thiele.