The Historical Flora of Middlesex gives an account of the phanogams and vascular cryptogams found since 1548 in the vice-county of Middlesex, with additional chapters on the Characeae and the Bryophyta. Middlesex includes the cities of London and Westminster and may appear at first sight to be the least interesting of all the English vice-counties – small in size, restricted in soils and habitat types, and so completely urbanised so as to leave scant space for natural or semi-natural vegetation. This notion is, however, refuted by the fact that upwards of 1,100 species are known to have occurred in the area; well over 200 more than the total species recorded by Trimen and Dyer in their Flora of Middlesex published in 1869. There is little doubt that the high level of human activity in Middlesex has provided new artificial habitats for many plants, thus gravel pits, chalk pits, rubbish tips, railway banks, motorway banks, canals and walls all have important roles in producing a great diversity in the plant populations. Pollution also plays a part. Though detrimental to many species, it has been shown that sulphur-contaminated soils and waters enriched with nitrates are beneficial to a few taxa.
The data presented in The Historical Flora of Middlesex are the result of over forty years of close association with the plants of Middlesex and of much literary research. Together they have enabled the author to present a unique and personal view of the changing panorama of Middlesex botany.
The set includes the original Historical Flora of Middlesex, published in 1975, and the Flora of Middlesex, a supplement to the first volume.