BOTANY r~ ~^HE botany of Hertfordshire has been thoroughly investigated with the exception of a few groups of cryptogamic plants, our knowledge of the lichens and of some of the microscopic fungi being the least extensive. Two floras of the county have been published. The first, the Flora Hertfordiensis of Webb and Coleman, which appeared in 1849, with supplements in 1851 and 1859, is noteworthy as being the first flora in which a county was divided into districts based upon the natural divisions of river-basins, a method now almost universally adopted. It originated in a list of local plants drawn up by the Rev. W. H. Coleman when residing at Hertford in 1838, and most of the records are his, the Rev. R. H. Webb, rector of Essendon, being responsible for the arrangement and production of the work. On the death of Mr. Webb in 1879, the botanical correspondence, manuscripts, and herbaria of Webb and Cole- man, and Mr. Webb's botanical library, were presented by Mrs. Webb to the Hertfordshire Natural History Society. In 1874 Alfred Reginald Pryor commenced the preparation of a new flora of Hertfordshire, working assiduously at it in the field and in the study until his death in 1881, except when interrupted, as he frequently was, by illness. He bequeathed to the Hertfordshire Natural History Society his botanical library, manuscripts, and the sum of 100. The result was that the society undertook the publication of Mr. Pryor's unfinished flora, securing the services of Mr. B. Daydon Jackson, botani- cal secretary of the Linnean Society, as editor. This work 1 forms the basis of the present article. The classification and nomenclature, which are in accordance with Nyman's Conspectus Florae Europeeee (187885), have here been altered in order to conform as far as possible with Hooker's Student's Flora of the British Islands (3rd ed. 1884). This has proved to be a tedious operation, for Mr. Pryor worked with Babington's Manual, and with Nyman's Conspectus as the successive parts of that work appeared, and his views on nomenclature differed as widely as possible from those of Sir Joseph Hooker. The forms which he considered to be distinct species are here as a rule treated as such, but in the flowering plants Hooker's names are in all cases adopted, Pryor's, when better known or more generally used, being added within brackets. 1 A Flora of Hertfordshire, by the late Alfred Reginald Pryor, edited for the Hertfordshire Natural History Society by Benjamin Daydon Jackson, with an Introduction on the Geology, Climate, Botanical History, etc., of the County, by John Hopkinson and the Editor, pp. Iviii. 588 (London and Hertford, 1887). 43