Richard Hook Richens
Richard Hook Richens (1919–1984) was a Director of the Commonwealth Bureau of Plant Breeding and Genetics (part of the Commonwealth Agricultural Bureaux) at Cambridge University, and became best known for his studies of elm (Ulmus). 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 var. vulgaris. Richens' all-England collection of specimen elm leaves, along with comparative samples from the Continent, assembled at the Cambridge Department of Applied Biology, is now held at the Cambridge University Herbarium in the Sainsbury Laboratory.
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.
Impact of DNA fingerprinting
Richens' approach has been much criticized since his death, and some of his taxonomy challenged or discarded. Dr Max Coleman of the Royal Botanic Garden, Edinburgh writes, however (2009): "The advent of DNA 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." 
- (1946). The New Genetics of the Soviet Union. (co-author with P. S. Hudson).
- (1955). Studies on Ulmus 1. The range of variation of East Anglian elms. Watsonia 3: 138–153.
- (1956). Elms. New Biology 20: 7–29.
- (1958). Studies on Ulmus II. The village elms of southern Cambridgeshire. Forestry 31: 132–146.
- (1959). Studies on Ulmus III. The village elms of Hertfordshire. Forestry 32: 138–154.
- (1960). Cambridgeshire elms. Nature in Cambridgeshire 3: 18–22.
- (1961)a. Studies on Ulmus IV. The village elms of Huntingdonshire and a new method for exploring taxonomic discontinuity. Forestry 34: 47–64.
- (1961)b. Studies on Ulmus V. The village elms of Bedfordshire. Forestry 34: 185–206.
- (1965). Studies on Ulmus VI. Fenland elms. Forestry 38: 225–235.
- (1967). Studies on Ulmus VII. Essex elms. Forestry 40: 185–206.
- (1968). The correct designation of the European Field Elm. Feddes Repertorium Speciorum Novarum Regni Vegetabilis 79: 1–2.
- (1976). Variation, cytogenics and breeding of the European Field Elms. Annales Forestales Analiza Sumartsvo (Zagreb) 7: 107–141.
- (1977). New designations in Ulmus minor Mill. Taxon 26: 583–584.
- (1978). Multivariate analysis of the elms of northern France and England: pooled analysis of the elm populations of northern France and England. Silvae Genetica 27: 85–95. (co-author Jeffers, J.N.R.).
- (1980). On fine distinctions in Ulmus L. Taxon 29: 305–312.
- (1981). Elms (Genus Ulmus). In: Hora, B. (ed.) The Oxford Encyclopaedia of Trees of the World. Oxford: OUP, 150–152.
- (1983). Elm. Cambridge University Press. ISBN 0521249163
- (1984). Ulmus × hollandica Miller var. insularum Richens var. nov. Watsonia 15: 105–108.
- (1985). The elms of Wales. Forestry 58: 9–25.
- Richens, R. H., Elm (Cambridge 1983), Preface p.xi
- Sparck-Jones, "R.H. Richens" in Hutchins (ed.) Early Years in Machine Translation: Memoirs and biographies of pioneers, John Benjamins, 2000, p.263
- Max Coleman, ed.: Wych Elm (Royal Botanic Garden Edinburgh publication, 2009; ISBN 978-1-906129-21-7); p. 22
- IPNI. Richens.
- Armstrong, J. V. & Sell, P. D. (1996). A revision of the British elms (Ulmus L., Ulmaceae): the historical background. Bot. J. Linn. Soc. 120: 39–50.
- Richens, R.H. General program for mechanical translation between any two languages via an algebraic interlingua [Abstract]. In: Report on research: Cambridge Language Research Unit. Mechanical Translation 3 (2), November 1956; p. 37.
- Richens, R.H. Preprogramming for mechanical translation. Mechanical Translation 3 (1), July 1956; pp. 20–25