Career
His most famous publication was the seminal Elm, published in 1983, in which he sank many elms formerly treated as species as mere varieties or subspecies of Ulmus minor, notably the English Elm U. procera, which he renamed U. minor various vulgaris. Although a professional botanist, Richens also had a personal interest in machine translation, carrying out important early work on the subject in collaboration with Margaret Masterman and Michael Halliday, and later at the Cambridge Language Research Unit. Richens" approach has been much criticized since his death, and some of his taxonomy challenged or discarded.
Doctor Max Coleman of the Royal Botanic Garden, Edinburgh writes, however (2009): "The advent of deoxyribonucleic acid fingerprinting has shed considerable light on the question.
A number of studies have now shown that the distinctive forms that Melville elevated to species and Richens lumped together as field elm are single clones, all genetically identical, that have been propagated by vegetative means such as cuttings or root suckers. This means that enigmatic British elms such as Plot Elm and English Elm have turned out to be single clones of field elm.
Although Richens did not have the evidence to prove it, he got the story right by recognising a series of clones and grouping them together as a variable species.".
