Clapham, A.R., Tutin, T.G. & Warburg, E.F., 1962
Flora of the British Isles
With over 1,000 thin pages of small type, "CTW" was, for thirty years, the standard flora for the higher plant botanist in Britain.
The keys work well and the descriptions are sufficently detailed to enable confident identification.
The species entries are a mine of information, giving flowering (and often fruiting) period (noticeably inaccurate in these days of climate change), chromosome counts (showing, for example, that Lady's Smock - Cardamine pratensis - is actually a neglected complex of microspecies), pollenators (several Helleborines - Epipactis - are wasp-pollenated) status, no of vice counties, distribution in Britain and abroad.
||Cambridge University Press (CUP)
||All native species and hybrids known at the time, plus a good selection of the commoner aliens and garden escapes.
||A few line drawings in the text.
||In the Hand (also useful to examine with x8 or x10 hand lens).
||Clapham, A.R., Tutin, T.G. & Warburg, E.F. (Roles, S.J. del), 1957
|the shortened, more portable, "Excursion Flora"
||Clapham, A.R., Tutin, T.G. & Warburg, E.F., 1968