In preparing the paper, Brown had complete access to the herbarium of his patron, Sir Joseph Banks, which included the specimens he had collected during Flinders' voyage, and which contained the most extensive collection of Proteaceae in the world. He was also given access to James Edward Smith's Linnean collection; the herbarium of Aylmer Bourke Lambert; the living collections of George Hibbert; the herbarium of William Aiton, which contained the collections of Francis Masson; and the collections of William Roxburgh. In addition he was accorded a brief examination of the specimens collected by Jacques Labillardière on the west coast of Australia, where Brown had not collected.
Brown's paper was read to the Linnean Society of London in four parts, on 17 January, 7 February, 21 February and 7 March 1809. The Council of the Society approved it for publication on 2 May, but it did not appear in print until 8 March 1810. It was published as a separate offprint under the title On the natural order of plants called Proteaceae, and also appeared in Volume 10 Part 1 of Transactions of the Linnean Society of London, under the title On the Proteaceae of Jussieu. It was illustrated by two Ferdinand Bauer plates, depicting Knightia excelsa and Dryandra formosa (now Banksia formosa).
The paper begins with a digression, presenting Brown's observations on undeveloped Asclepiadaceae flowers as evidence of the importance of studying developing flowers as well as mature ones. It then discusses the biogeography of Proteaceae, noting the southern hemisphere (that is, Gondwanan) distribution of the family, and that "[t]he most numerous genera are also the most widely diffused." Brown then discusses the morphology of the family, including a discussion of pollen shape; according to David Mabberley this represents "the first major study of the subject, palynology".
The systematics section follows, and is most important for the large number of new taxa published therein. 404 species in 38 genera are listed. 18 of the genera are new, and nearly all of these are still upheld. The arrangement of these genera largely follows that introduced by Richard Salisbury in his 1806 The Paradisus Londonensis, although Brown asserts that he arrived at his arrangement independently. Brown does introduce one important concept, however: his division of the Proteaceae into two subfamilies based on characteristics of the fruit is still considered the fundamental division in the family.
Overall, the paper was very well received; according to Mabberley, "[t]he paper was masterful and commanded respect for Brown as a brilliant botanist."
Salisbury was accused of plagiarism and ostracised from botanical circles. Contemporary notes and letter indicate widespread condemnation of Salisbury's actions. For example, Samuel Goodenough wrote "How shocked was I to see Salisbury's surreptitious anticipation of Brown's paper on new Holland plants, under the name and disguise of Mr. Hibbert's gardener! Oh it is too bad!"; and James Edward Smith wrote that he had a copy of Knight's paper "but shall not keep it — I mean hereafter not to notice it or any other of the author's productions." Brown himself wrote of Salisbury "I scarcely know what to think of him except that he stands between a rogue and a fool."
With the passage of time, some dissenting views have emerged. In 1870, Charles Babbington wrote that "Knight's Proteaceae is very curious if the best part of its was really carried away from a Linnean meeting and appropriated by Salisbury to tease R. Brown"; and other authors have since denied Salisbury's involvment. In 1985 David Mabberley offered the following in Salisbury's defence: "If Salisbury was guilty, why did he do it? ... [N]o doubt Salisbury felt that Brown was encroaching on his territory, for he had been writing on, and studying, Proteaceae for some time, and here was the Librarian of Smith's Linnean Society dashing off a paper to get his names into Hortus kewensis, criticizing Salisbury and abandoning some of his names on the way. It seems not inconceivable, therefore, that Salisbury... would have made amendments to Knight's final manuscript in the light of Brown's remarks... and hurried it through the press to defeat the machinations of his enemy."