There is still apparently some confusion concerning the most appropriate scientific name for pecan: Carya illinoensis, or C. illinoinensis. As one who has been involved in the debate, I would like to offer clarification. Most horticulturists use the spelling illinoensis. In fact, that spelling is specified in the ASHS Publications Manual (1991). This is consistent with the recommendation of the Crop Advisory Committee for Pecans and Hickories [Grauke, 1985, HortScience 20(4):629-630.]. At the time that recommendation was made, a proposal to conserve the name of pecan as Carya illinoensis (Wangenheim) K. Koch was submitted to the Standing Committee for Stabilization of Nomenclature, for consideration at the meeting at the XIVth International Botanical Congress in Berlin, July 1987 (Grauke et al., 1987, Taxon 35:174-177). We were confident that the proposal would be accepted, given the long history of that name's usage and the fact that previous Botanical Congresses, although lacking a mechanism for authoritative implementation, had decided in favor of C. illinoensis (Schubert, 1969, Regime Veg. 60:110). Unfortunately, the proposal was rejected (Nicolson, 1988, Taxon 37:440). As a result, the appropriate scientific name of pecan is Carya illinoinensis (Wangenh.)K. Koch. The decision of the Nomenclature Committee was communicated to scientists involved with the study of pecan at the National Pecan Research-Extension Meeting, New Orleans, Jan. 1988, and was reflected in the minutes of the meeting.
Several colleagues have requested documentation of the decision and have provided that information to editors of ASHS. I would not have submitted the proposal for consideration by the Nomenclature Committee had I been unwilling to abide by their decision. I have therefore adopted use of the approved name. I recommend that the editorial policy of ASHS be revised, recognizing Carya illinoinensis (Wangenh.) K. Koch as the approved scientific name of pecan. (Please also note that the approved abbreviation of Koch's name is "K. Koch" in the Draft Index of Author Abbreviations compiled at the The Herbarium, Royal Botanical Gardens, Kew, 1980, rather than "C. Koch" as listed in the ASHS Publications Manual.)
L. J. Grauke, U.S. Dept. of Agriculture Pecan Breeding & Genetics Somerville, TX
Note: The name recommended for pecan by the American Society for Horticultural Science (600 Cameron Street, Alexandria VA 22314-2562) was changed in the ASHS Publications Style Manual, 1997, published by ASHS Press. See page 60 of that manual:
"The following scientific names are preferred by ASHS to those from other sources: Carya illinoinensis (Wangenh.) C. Koch……………………pecan".