The nutty world of hazel names – a critical taxonomic checklist of the genus Corylus (Betulaceae)

Abstract

Hazelnuts (Corylus L.) are the source of one of the globally most important nut crops. Despite their economic and cultural importance, taxonomic knowledge is poor, even the number of species is equivocal. Weak morphological differentiation, the inconsistent taxonomic treatment of horticultural selections and cultivars, and uncritical regional treatments generated a multitude of names. The situation is further complicated by an ancient history of use (at least 10 400 years), trade (at least 4000 years) and domestication (at least 2000 years). Here, we present an annotated checklist of the taxa in the genus Corylus based on an extensive literature review, electronic database research, and visits to some European herbaria. Full citations are given for all names, typifications are provided for the majority of them. Cultivars are listed if described under the rules of the ICN. We designate lectotypes and neotypes for 28 names, and discuss the identity of enigmatic C. maxima Mill., a taxon not known from the wild.

Resolving the Speciation Patterns and Evolutionary History of the Intercontinental Disjunct Genus Corylus (Betulaceae) Using Genome-Wide SNPs

“…Here, several scenarios for the treatments of ambiguous species were described. (1) Despite of an accepted name in The Plant List, C. colchica has few records ( Bobrov, 1936 ; Govaerts and Frodin, 1998 ) and remains a bit of uncertainty ( Holstein et al, 2018 ). Therefore, this alleged species is not considered to be included in our samples.…”

Nutrient Composition of Different Hazelnut Cultivars Grown in Germany

“…Since there is no concluding evidence which would favor the separation as an individual species and because of reported hybridization between both taxa, we do not discriminate between both species here. For a recent critical evaluation on Corylus taxonomy, we refer to Holstein et al [10]. For synonymous names of cultivars, the reader is referred to Mehlenbacher [11], NCGR-Corvallis Corylus catalogue [12], and information provided by the Food and Agriculture Organization of the United Nations (FAO) [13].…”

978. Corylus Chinensis

“…Farges in 1904. Another of Hickel's specimens collected earlier in 1910 bears the name Corylus papyrifera (Hickel, 1910), which was most probably a working name (Holstein et al ., 2018).…”