The sampling of weed vegetation and other assemblages of open habitats

In the days before political correctness was an issue, the editors of a renowned book on weeds made the memorable observation that, as a class, weeds had ‘much in common with criminals’: that is, when not engaged in nefarious activities, they were often admirable. Certainly, that book (Salisbury 1964), then and still the most accessible account of these plants, did much to inform and engage, and it grouped weeds into broad ecological categories according to habitat – cornfield and arable weeds, grassland weeds, weeds of sandy soils, of chalk, of roadsides and wastes, and of gardens. This was scarcely a classification, of course, but it was a considerable advance on Tansley (1939) which, like its predecessor (Tansley 1911), made only fleeting references to weed vegetation of any kind, and then usually within the context of successions to other plant communities. In fact, Salisbury himself (1964) was building on previous work, like the survey of Buckman (1856), who described arable weeds of different soil types, and the studies of Brenchley (1911, 1912, 1913), who made more comprehensive field lists in various localities, noting the geology, soils and crops with which the plants were associated.