Corylus avellana, in The Plant List, 2013

Holstein, Norbert, Tamer, Sarah el & Weigend, Maximilian, 2018, The nutty world of hazel names - a critical taxonomic checklist of the genus Corylus (Betulaceae), European Journal of Taxonomy 409, pp. 1-45 : 5-16

2a. Corylus avellana L. var. avellana

C. avellana var. sylvestris Ehrh., Hannoverisches Magazin 18: 234 ( Ehrhart 1780) nom. nud.

C. avellana var. grandis Aiton, Hortus Kewensis 3: 363 ( Aiton 1789). – C. grandis (Aiton) Nois., Manuel Complet du Jardinier, Maraicher, Pépiniériste, Botaniste, Fleuriste et Paysagiste 2: 464 ( Noisette 1825) (recombination, Art. 41.4, McNeill et al. 2012). – C. avellana var. cylindricochlamys Spach, Annales des Sciences naturelles, seconde série – Botanique 16: 106 ( Spach 1841) nom. illegit. superfl. – Original citation: only a reference to “ Corylus sativa fructu rotundo maximo ” ( Bauhin 1623: 418), which does not contain figures. – Type: not localized (no original specimen found in BM or K). – Note: Bauhin only cited “ Avellana urbana rotunda circa Lugdunum, Ges.hor. ” being an abbreviation for “ Gesnerus in libro de hortis Germaniae and Avellana major Lugdunensis, Cam. ” ( Cordus 1561: 249 r; Camerarius the Younger 1588: 24). Both citations lack figures, but describe a large and round fruited hazel from the area of Savoy, France and Lausanne, Switzerland (Gesner in Cordus 1561: 249 r). Aiton published the name grandis for the “cob nut”, apparently a popular group of cultivars with large round nuts back then and still widely cultivated, for example, in southern Italy and northern Spain. The form is morphologically close to the extant cultivar C. avellana ‘Barcelona’. Loudon (1838: 2018) even synonymized C. avellana var. grandis under his C. avellana var. barcelonensis , creating a superfluous name. Thus, C. avellana var. grandis would be the botanical name for the cultivated forms of Corylus with a large, round nut. They appear to have been in cultivation in Italy, France and Spain since ancient times and likely represent large-fruited selections of the wild C. avellana . All names cited under C. avellana var. cylindricochlamys Spach ultimately refer to Bauhin’s Corylus sativa fructu rotundo maximo ( Bauhin 1623), later published as C. avellana var. grandis Aiton. Therefore , Spach’s name is a homotypic synonym.

C. avellana var. sylvestris Aiton, Hortus Kewensis 3: 363 ( Aiton 1789) nom. inval. – C. sylvestris (Aiton) Salisb. , Prodromus Stirpium in Horto ad Chapel Allerton Vigentium: 392 ( Salisbury 1796) nom. inval. – Note: the citation of the name C. avellana var. sylvestris includes the type of C. avellana , and also Salisbury cites C. avellana .

C. avellana var. striata Willd. , Species Plantarum ed. 4 4 (1): 470 ( Willdenow 1805). – C. avellana var. striata Risso, Histoire Naturelle des Principales Productions de l’Europe Méridionale et particulièrement de Celles des Environs de Nice et des Alpes Maritimes 2: 332 ( Risso 1826) nom. illegit. (later homonym; Art. 53.4, McNeill et al. 2012). – Type: not localized. – Note: Risso most likely used Willdenow’s name without citing him.

C. avellana var. ovata Willd. , Species Plantarum ed. 4 4 (1): 470 ( Willdenow 1805). – C. avellana var. ovata Risso, Histoire Naturelle des Principales Productions de l’Europe Méridionale et particulièrement de Celles des Environs de Nice et des Alpes Maritimes 2: 331 ( Risso 1826) nom. illegit. (later homonym). – C. ovata Lam. ex Steud., Nomenclator Botanicus ed. 2 1: 424 ( Steudel 1840) nom. inval. pro syn. – Type: iconotype, Lamarck (1796 –1797: pl. 780n). – Note: Steudel’s name is often cited as Lam. ex Steud., but the author of the name is Willdenow. Willdenow described this variety based on a drawing in Lamarck’s Illustration des genres, which is more commonly cited as Tableau encyclopédique et méthodique ( Stafleu & Cowan 1976 –1988). Steudel most likely misinterpreted Willdenow’s reference to Lamarck’s figure and attributed the name to Lamarck. As Steudel cited the name in synonymy, it is invalid anyway.

C. avellana var. maxima Audib., Catalogue des Arbres, Arbrisseaux, Arbustes , et Plantes: 15 ( Audibert 1817). – Type: not localized (cult.). – Note: the term “ maxima ” is misapplied many times. In his C. maxima Mill., Miller (1768) explicitly refers to a Corylus with oblong fruits, whereas the fruits of C. avellana var. maxima Audib. are large and rounded, matching the morphology of C. avellana var. grandis . However, both names share long bracts that surpass the fruit, resulting in a similar external appearance.

C. avellana var. racemosa Risso, Histoire Naturelle des Principales Productions de l’Europe Méridionale et particulièrement de Celles des Environs de Nice et des Alpes Maritimes 2: 331 ( Risso 1826). – Type: not localized.

C. avellana var. crispa Loudon, Encyclopedia of Plants: 792 ( Loudon 1829). – Type: not localized. – Note: Loudon mentions C. avellana var. crispa briefly in the list ( Loudon 1829) explaining that it is frizzled (most likely the bracts) in contrast to the other hazels. The diagnosis is short, not an automatic translation of the epithet and distinguishing, and therefore meeting the diagnostic criterion as set in Art. 38.2 ( McNeill et al. 2012). There is a contemporary description without a Latin name by Lindley (1829, pl. 70), mentioning that this cultivar originated in a garden at Hoveton, near Norwich ( England). Loudon, however, cited Lindley only in his Arboretum et Fruticetum Britannicum ( Loudon 1838: 2018). The fruit is characterized by an elliptical nut enclosed in a flaring, laciniate involucre about twice its length ( Loudon 1838, fig. 1943).

C. avellana var. ardua Poit. & Turpin, Traité des Arbres Fruitiers 6: 46 ( Poiteau & Turpin 1835). – Type: not localized (from wild collection from Normandy, France). – Note: Poiteau & Turpin (1835) described this taxon, but they were not clear about its rank. Although the name in the title points to the rank of a species, being in the same style as it is done for C. avellana , they wrote in the first sentence that this is supposed to be a variety. We hence follow this designation. In a later publication ( Poiteau 1846: 214), they added the information that this taxon was first cultivated by Hericard Ferrand in rue Sainte-Catherine, Paris, in 1812.

C. avellana var. microphylla Lej., Compendium Florae Belgicae 3: 256 ( Lejeune & Courtois 1836). – Original citation: “in Ardenna.” – Type: [ Belgium, Région wallonne, Liège] À Monganbroux [Mangombroux, today a quarter in Verviers], 1832, A.L.S. Lejeune s.n. (lecto-, designated here: BR!).

C. avellana var. barcelonensis Loudon, Arboretum et Fruticetum Britannicum 3: 2018 ( Loudon 1838) nom. illegit. superfl. (superfluous as Loudon cited C. avellana var. grandis Aiton ).

C. avellana var. lambertii Loudon, Arboretum et Fruticetum Britannicum 3: 2018 ( Loudon 1838). – Type: not localized. – Note: this name is used for a cultivated variety from Loddiges garden catalogue ( Loddiges 1836). However, in contrast to the Lambert’s nut in the sense of C. maxima (where the name may be derived from Lombardy), this name for a cultivar is supposedly derived from a plant breeder named Lambert, most likely for what is today widely called “Kentish Cob” ( Bunyard 1920). It has an oblong nut with a rather rounded apex and the involucre barely exceeding the nut in length.

C. avellana var. pumila Loudon, Arboretum et Fruticetum Britannicum 3: 2017 ( Loudon 1838). – C. pumila Lodd., Catalogue of Plants ed. 16: [page unknown] ( Loddiges 1836) nom. nud. – Type: not localized.

C. avellana var. glandulosa Godet, Mémoires de la Société des sciences naturelles de Neuchâtel 2: 15 [“ Dicotyledones ”], 3 [“ Additions et corrections en 1838 ”] ( Godet 1839). – C. glandulosa (Godet) Shuttleworth ex Godet, Flore du Jura: 639 ( Godet 1853). – Original citation: “Au dessus de Nods et de Lignières, au pied de Chasseral.” – Type: Switzerland, in dumetis ad pedem M. Chasseral prope Lignières, et versus Nods, et in vall. Lignières frequens, 5 Jul. 1835, R.J. Shuttleworth s.n. (lecto-, designated here: NEU! [acc. no. 204561]). – Original material: Switzerland, in dumetis ad pedem M. Chasseral versus nods et in Vall. Lignières ubique, 6 Jul. 1835, R.J. Shuttleworth s.n. (BM!). – Note: initially, Godet’s name lacks a description that he adds in “ Additions et corrections en 1838 ” lateron (submitted on 31 Dec. 1838), so only then the publication can be regarded as valid. The name C. glandulosa also appears on a specimen collected by E. Perrier in P (P06810712) and is referred to be by Ehrhart, however, the present authors are unaware of any Ehrhart publication of this name.

C. arborea hort. ex Steud., Nomenclator Botanicus ed. 2 1: 424 ( Steudel 1840) nom. inval. pro syn.

C. avellana var. brachychlamys Spach, Annales des Sciences naturelles, seconde série – Botanique 16: 106 ( Spach 1841) nom. illegit. superfl. – Note: Spach cited C. avellana var. ovata Willd. and a “ Corylus avellana var. sylvestris ”, which is most likely the name of Aiton, therefore this name is superfluous.

C. avellana var. macrochlamys Spach, Annales des Sciences naturelles, seconde série – Botanique 16: 106 ( Spach 1841) nom. illegit. superfl. – Note: Spach cited C. avellana var. glomerata hort. (Kew), which was published by Aiton, but also C. avellana var. maxima Audib. , which is regarded as synonymous to C. avellana var. grandis .

C. avellana var. schizochlamys Spach, Annales des Sciences naturelles, seconde série – Botanique 16: 106 ( Spach 1841). – Original citation: “Commune dans les bois aux environs de Paris.” – Type: not localized. – Note: based on the name chosen, Spach referred to the very common form of C. avellana with deeply dissected involucre.

C. avellana var. sphaerocarpa Rchb., Icones Florae Germanicae et Helveticae 12: 5, pl. DXXXVIII: 1302 ( Reichenbach 1850). – Type: not localized (the iconotype would be in loc. cit.). – Note: Reichenbach mentioned that this variety was intermediate between C. avellana s.str. and “ C. grandis ” ( C. avellana var. grandis Aiton ).

C. spicata G.Kirchn., Arboretum Muscaviense : 673 ( Petzold & Kirchner 1864). – Type: not localized (cult. in the State nursery near Sanssouci, Potsdam, Germany).

C. avellana var. latifolia hort. ex A.DC., Prodromus Systematis Naturalis Regni Vegetabilis 16 (2): 131 ( Candolle 1864). – C. filicifolia hort. ex A.DC., Prodromus Systematis Naturalis Regni Vegetabilis 16 (2): 131 ( Candolle 1864) nom. inval. pro syn. – Type: not localized. – Note: De Candolle mentioned a large-leaved variety latifolia that has been in gardens as “ latifolia ” and “ filicifolia ”.

C. hispanica K.Koch, Die Deutschen Obstgehölze : 607 ( Koch 1867). – Type: not localized (from cultivation). – Note: Koch discussed the early hazel names and mentioned that the taxon behind his C. hispanica was already mentioned by Gesner ( Cordus 1561: 249 r). It is therefore evident that this is yet another name for what had already been described as C. avellana var. grandis Aiton.

C. avellana var. mediopurpurea Späth, Baumschule. Haupt-Preis-Verzeichniss, 1883 57: 2 ( Späth 1883). – Type: not localized. – Note: the present authors did not have the protologue at hand for verification of the validity. Späth (1885) described the cultivar as having a red marking in the leaf center.

C. avellana var. gloiotricha Beck, Fl. Nieder-Oesterreich 1: 267 ( Beck von Mannagetta 1890). – Original citation: “In Voralpen.” – Type: not localized.

C. avellana var. glaucescens Borbás, C. Baenitz Herbarium Europaeum no. 8333 (1895–1896) nom. nud. in sched. – Associate material: Hungaria centr., Budae-Pestini, in declivibus nemoris Zugliget, Aug. 1895, V. de Borbás s.n. (M!, P06809854!, P06809903!, P06810667!, P06810668!, WU!). – Note: to the present authors’ knowledge, this is an unpublished name for a hazel with a glaucous lower leaf lamina.

C. avellana var. zimmermannii Hahne, Mitteilungen der Deutschen dendrologischen Gesellschaft 12: 127 (Beissner 1903). – Original citation: “Zu Ende September 1903 machte mich Herr Lehrer E. Zimmermann in Schwelm [Northrhine-Westphalia, Germany; …] eine alte Hecke im Süden der Stadt, zu führen.” – Type: not localized (if in BONN, then destroyed). – Note: this is a formal description for a mutation in which the leaf bases are connected to form a cone. Hahne lived in Bonn-Poppelsdorf, so there may have been a specimen at BONN, but the herbarium was largely destroyed in 1944 and there is no extant material. Also, the author’s intention to graft the mutation for further study was apparently not followed. Krüssmann (1960: 351) lists this name as a cultivar, but mixing up the birth place and year of E. Zimmermann with the original collection data in his reference. As an aberrant individual, it does not deserve taxonomic recognition.

C. avellana f. peltata Buser, Société pour l’Étude de la flore franco-helvétique no. 1544 (Buser 1904) in sched. – Type: Switzerland, Geneva, haies à Lancy, 30 Sep. 1903, R. Buser s.n. (syn-: P05591949!, P06809904!, P06810696!). – Note: the name was also published in the Bulletin of the Société pour l’Étude de la flore franco-helvétique, which is a short list in the Bulletin de l’Herbier Boissier ( Camus et al. 1905: 974, 976).

C. avellana f. grandifolia Zapał., Conspectus Florae Galiciae Criticus 2: 10 ( Zapałowicz 1908). – Original citation: “Ojców (Rehman).” – Type: not localized (likely in KRAM, cf. Stafleu & Cowan 1976 –1988).

C. avellana var. acuminata Henriksson, Botaniska Notiser 1915 (5): 247 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Gunnarsnäs ad Östevatten, J. Henriksson s.n. (holo-: not localized).

C. avellana var. acutiuscula Henriksson, Botaniska Notiser 1915 (5): 244 ( Henriksson 1915). – Type: Sweden, in Helsingia, paroecia Segerstad ad Elftorp, C. Strandberg s.n. (holo-: not localized).

C. avellana var. amblyocarpa Henriksson, Botaniska Notiser 1915 (5): 244 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Holm ad Hålsungebyn, P.J. Örtengren s.n. (syn-: not localized); Sweden, Dalia, paroecia Gunnarsväs ad Mörtviken, J. Henriksson s.n. (syn-: not localized).

C. avellana var. apiculata Henriksson, Botaniska Notiser 1915 (5): 241 ( Henriksson 1915). – Type: Sweden, Helsingia, paroecia Segerstad ad Elftorp, C. Strandberg s.n. (syn-: not localized); Sweden, Dalia, paroecia Holm ad Hålsungebyn, P.J. Örtengren s.n. (syn-: not localized).

C. avellana var. arcuata Henriksson, Botaniska Notiser 1915 (5): 239 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Gunnarsväs ad Hällan, Backerud et Östevatten, J. Henriksson s.n. (syn-: not localized); Sweden, Dalia, paroecia Holm ad Hålsungebyn, P.J. Örtengren s.n. (syn-: not localized).

C. avellana var. cervispina Henriksson, Botaniska Notiser 1915 (5): 244 ( Henriksson 1915). – Type: Sweden, in Oelandia, paroecia Bröttorp et Hålsungebyn, P.J. Örtengren s.n. (holo-: not localized).

C. avellana var. compressa Henriksson, Botaniska Notiser 1915 (5): 241 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Gunnarsnäs, ad Mörtviken, J. Henriksson s.n. (syn-: not localized); Sweden, Dalia, paroecia Ertemark ad Bengtsfors, J. Henriksson s.n. (syn-: not localized).

C. avellana var. cryptomeria Henriksson, Botaniska Notiser 1915 (5): 241 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Holm ad Bröttorp, P.J. Örtengren s.n. (syn-: not localized); Sweden, Dalia, paroecia Ertemark ad Bengtsfors, 1 Aug. 1914, J. Henriksson s.n. (syn-: not localized; isosyn-: LD1780253); Sweden, Dalia, paroecia Gunnarsnäs ad Hjulsängen et Östevatten, paroecia Ör ad Långeerud, J. Henriksson s.n. (syn-: not localized).

C. avellana var. distans Henriksson, Botaniska Notiser 1915 (5): 239 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Gunnarsnäs ad Backerud, 160 m a.s.l., 16 Sep. 1915, J. Henriksson s.n. (syn-: not localized; isosyn-: LD1798219); Sweden, in Oelandia, paroecia Vickleby ad Vicklevy, J. Ekström s.n. (syn-: not localized).

C. avellana var. ellipsoidea Henriksson, Botaniska Notiser 1915 (5): 246 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Ertemark ad Bengtsfors, J. Henriksson s.n. (syn-: not localized); Sweden, Dalia, paroecia Ertemark ad Huvudgingen, 1 Aug. 1914, J. Henriksson s.n. (syn-: not localized; isosyn-: LD1793482).

C. avellana var. elongata Henriksson, Botaniska Notiser 1915 (5): 246 ( Henriksson 1915). – Type: Sweden, in Smolandia, paroecia Femsjö ad Olastorp, H. Persson s.n. (syn-: not localized); Sweden, Dalia, paroecia Holm ad Bröttorp, P.J. Örtengren s.n. (syn-: not localized).

C. avellana var. fusiformis Henriksson, Botaniska Notiser 1915 (5): 246 ( Henriksson 1915). – Type: Sweden, in Oelandia, paroecia Vickleby ad Vickleby, J. Ekström s.n. (syn-: not localized); Sweden, Dalia, paroecia Holm ad Bröttorp, P.J. Örtengren s.n. (syn-: not localized); Sweden, Dalia, paroecia Gunnarsnäs ad Hjulsängen, J. Henriksson s.n. (syn-: not localized).

C. avellana var. gibbosa Henriksson, Botaniska Notiser 1915 (5): 245 ( Henriksson 1915). – Type: Sweden, in Smolandia, paroecia Femsjö ad Olastorp, H. Persson s.n. (syn-: not localized); Sweden, Dalia, paroecia Holm ad Hålsungebyn, P.J. Örtengren s.n. syn-: not localized); Sweden, Dalia, paroecia Ärtemark ad Bengtsfors et Huvudgingen, 1 Aug. 1914, J. Henriksson s.n. (syn-: not localized; isosyn-: LD1793418).

C. avellana var. glabrata Henriksson, Botaniska Notiser 1915 (5): 246 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Holm ad Hålsungebyn, P.J. Örtengren s.n. (holo-: not localized).

C. avellana var. integra Henriksson, Botaniska Notiser 1915 (5): 241 ( Henriksson 1915). – Type: Sweden, in Smolandia, paroecia Femsjö ad Olastorp, H. Persson s.n. (syn-: not localized); Sweden, Oelandia, paroecia Vickleby as Vickleby, J. Ekström s.n. (syn-: not localized).

C. avellana var. involucrata Henriksson, Botaniska Notiser 1915 (5): 245 ( Henriksson 1915). – Type: Sweden, in Oelandia, paroecia Böda ad Böda, O. Carlsson s.n. (syn-: not localized); Sweden, Dalia, paroecia Holm ad Hålsungebyn, P.J. Örtengren s.n. (syn-: not localized).

C. avellana var. lacerata Henriksson, Botaniska Notiser 1915 (5): 244 ( Henriksson 1915). – Type: Sweden, in Smolandia, paroecia Femsjö ad Olstorp, H. Persson s.n. (syn-: not localized); Sweden, Bahusia ad Rödbo prope oppidum Kungelv, K. Gustafson s.n. (syn-: not localized); Sweden, Dalia, paroecia Holm ad Bröttorp, P.J. Örtengren s.n. (syn-: not localized); Sweden, Dalia, paroecia Gunnarsnäs, ad Stakelund, J. Henriksson s.n. (syn-: not localized).

C. avellana var. lata Henriksson, Botaniska Notiser 1915 (5): 240 ( Henriksson 1915). – Type: Sweden, in Gotlandia, paroecia Hejde, S.J. Stengård s.n. (syn-: not localized); Sweden, Helsingia, paroecia Segerstad ad Elftorp, C. Strandberg s.n. (syn-: Not localized); Sweden, Dalia, paroecia Gunnarsnäs as Östevatten, J. Henriksson s.n. (syn-: not localized).

C. avellana var. limbata Henriksson, Botaniska Notiser 1915 (5): 240 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Gunnarsnäs, ad Mörtviken, 120 m a.s.l., 14 Sep. 1915, J. Henriksson s.n. (syn-: not localized; isosyn-: BR!, LD1797982, PH 00006756!); Sweden, Dalia, paroecia Gunnarsnäs ad Backerud, Hjulsängen, Östevatten, J. Henriksson s.n. (syn-: not localized); Sweden, in Oelandia, par Vickleby as Vickleby, J. Ekström s.n. (syn-: not localized); Sweden, Bahusia, paroecia Ryr ad Heljebol, J. Henriksson s.n. (syn-: not localized); Sweden, Dalia, paroecia Ertemark ad Bengtsfors, J. Henriksson s.n. (syn-: not localized).

C. avellana var. menthoides Henriksson, Botaniska Notiser 1915 (5): 241 ( Henriksson 1915). – Type: Sweden, in Oelandia, paroecia Böda ad Böda, O. Carlsson s.n. (holo-: not localized).

C. avellana var. oblonga G.Andersson, Botaniska Notiser 1915 (5): 245 ( Henriksson 1915). – Type: Sweden, in Dalia, paroecia gunnarsnäs ad Östevatten et Hjulsängen, paroecia Ertemark ad Bengtsfors, J. Henriksson s.n. (syn-: not localized); Sweden, Smolandia, paroecia Femsjö ad Olastorp, H. Persson s.n. (syn-: not localized).

C. avellana var. obovata Henriksson, Botaniska Notiser 1915 (5): 245 ( Henriksson 1915). – Type: Sweden, in Bahusia ad Rödbo prope Kungelv, K. Gustafson s.n. (syn-: not localized).

C. avellana var. pectinata Henriksson, Botaniska Notiser 1915 (5): 246 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Gunnarsnäs, ad Östevatten, J. Henriksson s.n. (holo-: not localized).

C. avellana var. sulcata Henriksson, Botaniska Notiser 1915 (5): 241 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Gunnarsnäs ad Östevatten, J. Henriksson s.n. (holo-: not localized).

C. avellana var. teretiuscula Henriksson, Botaniska Notiser 1915 (5): 239 ( Henriksson 1915). – Type: Sweden, in Smolandia, paroecia Femsjö ad Olastorp, H. Persson s.n. (syn-: not localized); ibid., Oelandia, paroecia Vickleby ad Vickleby, J. Ekström s.n. (syn-: Not localized).

C. avellana var. truncata Henriksson, Botaniska Notiser 1915 (5): 247 ( Henriksson 1915). – Type: Sweden, in Smolandia, paroecia Femsjö ad Olastorp, H. Persson s.n. (syn-: not localized); Sweden, Dalia, paroecia holm ad Bröttorp, P.J. Örtengren s.n. (syn-: not localized).

C. avellana var. turgida Henriksson, Botaniska Notiser 1915 (5): 240 ( Henriksson 1915). – Type: Sweden, in Gotlandia, paroecia Hejde, S.J. Stengård s.n. (syn-: not localized); Sweden, Bahusia paroecia Ryr ad Heljebol, J. Henriksson s.n. (syn-: not localized); Sweden, Dalia, paroecia Gunnarsnäs, ad Östevatten, J. Henriksson s.n. (syn-: not localized).

C. avellana var. velutina Henriksson, Botaniska Notiser 1915 (5): 240 ( Henriksson 1915). – Type: Sweden, Dalia, paroecia Holm ad Hålsungebyn, P.J. Örtengren s.n. (syn-: not localized); Sweden, paroecia Gunnarsnäs ad Östevatten, J. Henriksson s.n. (syn-: not localized [not LD1798302]).

C. avellana var. bulbosa Henriksson, Botaniska Notiser 1918 (6): 299 ( Henriksson 1918). – Type: Denmark, Naerum railway station, E. Petersen s.n. (holo-: not localized).

C. avellana var. cuneata Henriksson, Botaniska Notiser 1918 (6): 299 ( Henriksson 1918). – Type: Denmark, Naerum railway station, E. Petersen s.n. (holo-: not localized).

C. avellana var. cupulifera Henriksson, Botaniska Notiser 1918 (6): 299 ( Henriksson 1918). – Type: Denmark, Naerum railway station, E. Petersen s.n. (holo-: not localized).

C. avellana var. orbicularia Henriksson, Botaniska Notiser 1918 (6): 299 ( Henriksson 1918). – Type: Norway, southern Bergenhus amt, Störd [Stord], T. Bredal s.n. (holo-: not localized).

C. avellana var. praefracta Henriksson, Botaniska Notiser 1918 (6): 297 ( Henriksson 1918). – Type: Sweden, Dalia, paroecia Gunnarsnäs in silva Hällan ad Mörtviken, J. Henriksson s.n. (holo-: not localized).

C. avellana var. annulata Henriksson, Botaniska Notiser 1923 (3): 283 ( Henriksson 1923). – Type: Sweden, Dalia, paroecia Gunnarsnäs ad Östevatten, P.J. Örtengren s.n. (syn-: not localized); Sweden, Dalia, paroecia Gunnarsnäs ad Östevatten, J. Henriksson s.n. (syn-: not localized).

C. avellana var. attenuata Henriksson, Botaniska Notiser 1923 (3): 280 ( Henriksson 1923). – Type: Sweden, Dalia, paroecia Gunnarsnäs, ad Mörtviken, J. Henriksson s.n. (syn-: not localized); Sweden, Bahusia, paroecia Tanum ad Rörvik haud procul a Grebbestad, V. Andersson s.n. (syn-: not localized).

C. avellana var. coelata Henriksson, Botaniska Notiser 1923 (3): 280 ( Henriksson 1923). – Type: Sweden, Dalia, paroecia Holm ad Bröttorp, P.J. Örtengren s.n. (syn-: not localized); Sweden, Dalia, paroecia Gunnarsnäs ad sanatorium Kroppefjäll, J. Henriksson s.n. (syn-: not localized); Sweden, Ostrogothia, paroecia Landeryd ad Uvberget, P.H. Johansson s.n. (syn-: not localized).

C. avellana var. complanata Henriksson, Botaniska Notiser 1923 (3): 281 ( Henriksson 1923). – Type: Sweden, in Blekingia haud procul a Ronneby, E. Essén s.n. (syn-: not localized); Sweden, Dalia, paroecia Gunnarsnäs ad Östevatten, P.J. Örtengren s.n. (syn-: not localized); Sweden, Vestrogothia, paroecia Häggesled as Stinggården, G. Brandström s.n. (syn-: not localized); Sweden, Vestrogothia, paroecia Tun ad Gammaltorp, G. Brandström s.n. (syn-: not localized).

C. avellana var. extensa Henriksson, Botaniska Notiser 1923 (3): 281 ( Henriksson 1923). – Type: Sweden, Dalia, paroecia Holm ad Bröttorp et Hålsungebyn, P.J. Örtengren s.n. (syn-: not localized); Sweden, Dalia, Gunnarsnäs ad Mörtviken et Östevatten, J. Henriksson s.n. (syn-: not localized); Sweden, Uplandia, Gustavsberg ad Farsta, P.H. Johansson s.n. (syn-: not localized); Sweden, Vestrogothia, paroecia Tun ad Gammaltorp, G. Brandström s.n. (syn-: not localized).

C. avellana var. glandulosa Henriksson, Botaniska Notiser 1923 (3): 281 ( Henriksson 1923) nom. illegit. (later homonym). – Type: Sweden, in Blekingia prope Ronneby, E. Essén s.n. (syn-: not localized); Sweden, Dalia, paroecia Gunnarsnäs ad Mörtviken, J. Henriksson s.n. (syn-: not localized).

C. avellana var. ovalis Henriksson, Botaniska Notiser 1923 (3): 283 ( Henriksson 1923). – Type: Sweden, in Blekingia, Bustorp ad Ronnyby, E. Essén s.n. (syn-: not localized); Sweden, Dalia, paroecia Gunnarsnäs ad Östevatten, J. Henriksson s.n. (syn-: not localized); Sweden, Ostrogothia, paroecia Landeryd ad Uvberget, P.H. Johansson s.n. (syn-: not localized).

C. avellana var. subtecta Henriksson, Botaniska Notiser 1923 (3): 283 ( Henriksson 1923). – Type: Sweden, Dalia, paroecia Gunnarsnäs ad Östevatten, J. Henriksson s.n. (holo-: not localized).

C. avellana var. contracta Henriksson, Botaniska Notiser 1927 (2): 157 ( Henriksson 1927). – Type: Sweden, in Blekingia ad Persborg prope Ronneby, E. Essén s.n. (syn-: not localized); Sweden, Dalia, paroecia Gunnarsnäs ad sanatorium Kroppefjäll, J. Henriksson s.n. (syn-: not localized); Sweden, Sudermannia, paroecia Husby Rekarne ad Hedskolan, G. Pettersson s.n. (syn-: not localized).

C. avellana var. nitens Henriksson, Botaniska Notiser 1927 (2): 157 ( Henriksson 1927). – Type: Sweden, paroecia Gunnarsnäs ad sanatorium Kroppefjäll, J. Henriksson s.n. (holo-: not localized).

C. avellana var. prominens Henriksson, Botaniska Notiser 1927 (2): 156 ( Henriksson 1927). – Type: Sweden, in Bahusia, paroecia Tanum ad Vik prope Grebbestad, V. Andersson s.n. (syn-: not localized); Sweden, paroecia Gunnarsnäs ad sanatorium Kroppefjäll, J. Henriksson s.n. (syn-: not localized).

C. avellana var. retusa Henriksson, Botaniska Notiser 1927 (2): 157 ( Henriksson 1927). – Type: Sweden, Dalia, paroecia Gunnarsnäs ad sanatorium Kroppefjäll, J. Henriksson s.n. (holo-: not localized).

C. avellana var. secalina Henriksson, Botaniska Notiser 1927 (2): 156 ( Henriksson 1927). – Type: Sweden, Dalia, paroecia Laxarby ad Gårdsjö, N.I. Svensson s.n. (holo-: not localized).

C. avellana var. stylifera Henriksson, Botaniska Notiser 1927 (2): 159 ( Henriksson 1927). – Type: Sweden, in Vermelandia, paroecia Sillerud ad vicum Sillerud, H. Danielsson s.n. (holo-: not localized).

C. memorabilis Sennen, Plantes d’Espagne 1928 , no. 7082 (1928–1929) in sched. – Type: Spain [Catalonia], Barcelone, Massif de Tibidabo, e loco, 28 May 1928, Frère Sennen s.n. (syn-: not localized; isosyn-: BM!, PH 00006758, P06811312!); ibid., Barranco du Rabassalet, 28 May 1928, Frère Sennen s.n. in Exsicc. Ch. Duffour no. 6745 (syn-: not localized; isosyn-: BM!, P06809387!, P06809876!, P06809877!, P06809878!, P06809879!); ibid., 14 Aug. 1928 or 1929, Frère Sennen s.n. in Plantes d’Espagne no. 7082 (syn-: not localized; isosyn-: BM!, PH 00006758, P06811312!). – Note: the description is effectively published on printed labels accompanying the type specimens (Art. 30.7, McNeill et al. 2012). The name C. memorabilis appeared on labels before [Frère Sennen in Plantes d’Espagne no. 4805 (BM!, L!, L!) and Frère Sennen s.n. (BM!)], but was lacking a description. The sterile collections from 28 May 1928 were also distributed by the Société française in 1932 (Exsicc. Ch. Duffour) and are also type material.

C. avellana var. acuta Henriksson, Botaniska Notiser 1930 (2): 149 ( Henriksson 1930). – Type: Sweden, in Gotlandia, paroecia Lokrum ad Haltarve, G. Nilsson s.n. (holo-: not localized).

C. avellana var. glandifera Henriksson, Botaniska Notiser 1930 (2): 149 ( Henriksson 1930). – Type: Sweden, in Gotlandia, paroecia Lokrum ad Haltarve, G. Nilsson s.n. (holo-: Not localized).

C. avellana var. mucronata Henriksson, Botaniska Notiser 1930 (2): 149 ( Henriksson 1930). – Type: Sweden, Vestrogothia, paroecia Järpås ad Simmenebol, E. Brandström s.n. (holo-: not localized).

C. avellana var. pilosa Henriksson, Botaniska Notiser 1930 (2): 149 ( Henriksson 1930). – Type: Sweden, Vestrogothia, paroecia Järpås ad Simmenebol, E. Brandström s.n. (holo-: not localized).

C. avellana var. taeniensis Henriksson, Botaniska Notiser 1930 (2): 149 ( Henriksson 1930). – Type: Sweden, Vestrogothia, paroecia Järpås ad Simmenebol, E. Brandström s.n. (holo-: not localized).

C. avellana var. velutina f. monstrosa Henriksson, Botaniska Notiser 1930 (2): 150 ( Henriksson 1930). – Type: Sweden, Vestrogothia, paroecia Järpås ad Simmenebol, E. Brandström s.n. (holo-: not localized).

C. avellana var. brevilaciniata Henriksson, Botaniska Notiser 1931 (2): 213 ( Henriksson 1931). – Type: Sweden, in Hallandia, paroecia Knäred ad Ekernahult, E. Bengtsson s.n. (holo-: not localized).

C. avellana var. coniformis Henriksson, Botaniska Notiser 1931 (2): 213 ( Henriksson 1931). – Type: Sweden, Dalia, paroecia Gunnarsnäs ad Lottsbyn, M. Magnusson s.n. (holo-: not localized).

C. avellana var. divergens Henriksson, Botaniska Notiser 1931 (2): 213 ( Henriksson 1931). – Type: Sweden, Dalia, paroecia Gunnarsnäs ad Lottsbyn, M. Magnusson s.n. (holo-: not localized).

C. avellana var. gracilescens Henriksson, Botaniska Notiser 1931 (2): 214 ( Henriksson 1931). – Type: Sweden, Dalia, paroecia Gunnarsnäs ad Lottsbyn, M. Magnusson s.n. (holo-: not localized).

C. avellana var. indivisa Henriksson, Botaniska Notiser 1931 (2): 214 ( Henriksson 1931). – Type: Sweden, in Bahusia, paroecia Brastad ad Rixö, V. Nilsson s.n. (holo-: not localized).

C. avellana var. lenticularis Henriksson, Botaniska Notiser 1931 (2): 214 ( Henriksson 1931). – Type: Sweden, in Bahusia, paroecia Sanne ad Prästbol, A. Johansson s.n. (holo-: not localized).

C. avellana var. porrecta Henriksson, Botaniska Notiser 1931 (2): 214 ( Henriksson 1931). – Type: Sweden, in Bahusia, paroecia Brastad ad Rixö, V. Nilsson s.n. (holo-: not localized).

C. avellana var. pyramidata Henriksson, Botaniska Notiser 1931 (2): 214 ( Henriksson 1931). – Type: Sweden, in Bahusia, paroecia Brastad ad Rixö, V. Nilsson s.n. (holo-: not localized).

C. avellana var. simlicinerva Henriksson, Botaniska Notiser 1931 (2): 216 ( Henriksson 1931). – Type: Sweden, in Bahusia, paroecia Brastad ad Rixö, V. Nilsson s.n. (holo-: not localized).

C. avellana var. tiliifolia Murr, Veröffentlichungen des Tiroler Landesmuseums Ferdinandeum 11: 40 ( Murr 1931). – Original citation: “Silz-Mötz, am Höttinger Bild.” – Type: not localized.

C. mirabilis Sennen ex Bobrov, Sovietskaia Botanica 1936 (1): 28 ( Bobrov 1936b) nom. inval. pro syn. – Note: the present authors did not see any specimen with this label, but it may be the name was effectively and validly published on printed exsiccata labels just like C. memorabilis .

C. avellana f. monstrosa H.Lindb. , Plantae Finlandiae Exsiccatae no. 1123 ( Lindberg 1944) nom. illegit. superfl. (later homonym) in sched., non Henriksson (1930). – Type: Finland, Usimaa/ Nyland, paroecia Karis, Hållsnäs, 25 Aug. 1920, H. Lindberg s.n. (syn-: K!, WU!). – Note: this is a mutation with branched male catkins. The description is effectively published on printed labels accompanying the type specimens (Art. 30.7, McNeill et al. 2012), but illegitimate as it is a later homonym.

C. avellana f. peltata De Langhe , Bulletin de la Société Royale de Botanique de Belgique 106: 70 ( Langhe 1973) nom. illegit. (later homonym), non Buser (1904). – Type: Belgium, district Mosan, 1961, J.-E. De Langhe 544/1961 (holo-: Herbarium De Langhe).

C. avellana f. microphylla Gajić & Korac, Glasnik Prirodnaučkog Museja u Beogradu. Serija B Biološke nauke. Belgrade [Bulletin du Museum d’Histoire Naturelle Belgrade. Serie B. Sciences Biologiques. Belgrade] 33: 60 ( Gajić & Korać 1979) nom. illegit. (later homonym, Art. 53.4, McNeill et al. 2012), non C. avellana var. microphylla Lej. ( Lejeune & Courtois 1836) . – Type: Serbia / Kosovo, m. Ošljak, 1450 m a.s.l., 10 Jul. 1977, M. Gajić and M. Korać s.n. (holo-: not localized).

C. hispanica Mill. ex D.Rivera, Obón, S.Ríos, Selma, F.Méndez, Verde & F.Cano, Las Variedades Tradicionales de Frutales de la Cuenca del Río Segura. Catálogo Etnobotánico (1): Frutos Secos, Oleaginosos, Frutales de Hueso, Almendros y Frutales de Pepita: 37 ( Rivera Núñez et al. 1997) nom. illegit. superfl. (later homonym), non K.Koch ( Koch 1867). – Type: Spain, in Castillae Veterae, prope coenobio Sancta Clarae, in ditione Medina de Pomar (Burgos), 5 Aug. 1996, D. Rivera and C. Obón 47689 (holo-: MUB; iso-: MUB). – Note: Rivera Núñez et al. (1997) describe this long cultivated form as a new species, synonymizing several valid names below the species rank. Corylus avellana var. grandis Aiton. is however, already elevated to species rank by Noisette (1825), making this the oldest name for the taxon at species rank, if recognized. Futhermore, there is already a C. hispanica K.Koch , who described the same morphology. In all, C. hispanica Mill. ex D.Rivera, Obón, S.Ríos, Selma, F.Méndez, Verde & F.Cano is a later homonym.

C. avellana var. macrotruncus Zernov , Определитель сосудистых растений севера Российского ПричерноморьЯ: 94 ( Zernov 2002). – Type: Russia, Krasnodar, Novorossijsk, pylae Topolnaja-2, in valle rivuli, 18 Aug. 1999, A.S. Zernov 557 (holo-: MW; iso-: MOSP). – Note: this was described as a tree, but synonymized under C. avellana in The Plant List (2013) .

C. domestica Kosenko & Opalko , ІнтродукціЯ рослин на початку ХХІ століттЯ: ДосЯгненнЯ і перспективи (До 120-річчЯЗ днЯ народженнЯ академіка М.І.Вавилова):Матеріали Міжнародної наукової конференції (2–4 жовтнЯ 2007 р.): 70–74 ( Kosenko & Opalko 2007) nom. nud. – Note: Kosenko & Opalko (2007) published this name to accommodate the cultivated hazelnut, here considered as of hybrid origin from C. avellana , C. maxima , and C. avellana var. pontica . The protologue, however, lacks a type and a formal diagnosis (I. Kosenko, pers. com.), and has been used in a few Ukrainian publications mainly on hazel cultivation since then. However, the name refers to the same entity as C. hispanica and C. grandis , and the latter name would have priority. However, as a putative cultigen, the taxon should probably be better named following the code for cultivated plants (ICNCP, Brickell et al. 2009).

C. avellana var. alternata Henriksson nom. nud. in sched. – Associate material: Sweden, Dalia, paroecia Gunnarsnäs ad Mörtvkien, 100 m a.s.l., 30 Aug. 1926, J. Henriksson s.n. (LD1780125).

C. avellana f. coronata nom. nud. in sched. – Associate material: Sweden, Vestrogothia, paroecia Toarp, Skinnarhult, 14 Sep. 1921, O. Olson s.n. (LD1793794).

C. avellana f. sublobulata J.Erikson nom. nud. in sched. – Associate material: Sweden, Blekinge, Rödeby, 5 Sep. 1914, J. Erikson s.n. (LD1064362).

2aa. Corylus avellana ‘ Atlas ’

C. algeriensis Oct.Thomas, Guide Pratique de l’Amateur de Fruits : 36, 213 ( Thomas 1876). – Original citation: “D’Angleterre.” – Type: not localized. – Note: this is a Latin name given for an English cultivar called ‘Atlas’. The diagnosis is highly rudimentary, referring only to the clustered fruits.

2ab. Corylus avellana ‘ Aurea ’

C. avellana var. aurea G.Kirchn., Arboretum Muscaviense : 670 ( Petzold & Kirchner 1864). – C. avellana f. aurea (G.Kirchn.) Dippel, Handbuch der Laubholzkunde 2: 128 ( Dippel 1891) [“1892”]. – Type: not localized. – Note: Petzold was in contact to Schlechtendal in HAL ( Stafleu & Cowan 1976 – 1988), possibly original material is found there. This is a yellow-leaved garden cultivar, best called C. avellana ‘Aurea’.

2ac. Corylus avellana ‘ Contorta ’

C. avellana var. contorta Bean, The Garden 54: 349 ( Bean 1898). – C. avellana f. contorta (Bean) Rehder , Bibliography of Cultivated Trees and Shrubs Hardy in the Cooler Temperate Regions of the Northern Hemisphere: 111 ( Rehder 1949). – Type: not localized. – Note: this is a still popular garden variety with cork-screw shaped branches that was originally discovered near Gloucester, England around the year 1850.

2ad. Corylus avellana ‘ Cosford ’

C. avellana var. tenuis Loudon, Arboretum et Fruticetum Britannicum 3: 2018, fig. 1943 ( Loudon 1838). – Type: iconotype (lecto-, designated here: Lindley 1829: pl. 55). – Note: Corylus avellana var. tenuis was created as a scientific name for the cultivar ‘Cosford’ ( Lindley 1829). We argue that the cultivar name should be used for what is clearly the result of a horticultural selection process.

2ae. Corylus avellana ‘ Fuscorubra ’

C. avellana f. fuscorubra Dippel, Handbuch der Laubholzkunde 2: 128 ( Dippel 1891) [“1892”]. – Type: iconotype, Goeschke (1887: tab. 4). – Note: Dippel cites a German description of this cultivar ‘Rotblättrige Waldnuss’ by Goeschke (1887: 46), who found it in the arboretum of Reinhardt Behnsch in Dürrgoy (Tarnogaj) near Breslau (Wrocław, Poland). This is a red-leaved cultivar whose leaf coloration fades soon, and which has an involucre shorter than half of the nut.

2af. Corylus avellana ‘ Impériale de Trébizonde ’

C. macrocarpa Oct.Thomas, Guide Pratique de l’Amateur de Fruits : 36, 213 ( Thomas 1876). – Type: not localized. – Note: Corylus macrocarpa is a Latin name given for a cultivar called ‘Impériale de Trébizonde’. The name has been published in garden catalogs before, but the present authors are unaware of an accompanying description. The cultivar is still widely grown and offered for sale.

2ag. Corylus avellana ‘ Pendula ’

C. avellana var. pendula Nestel , Nestel’s Rosengarten 2: 17 ( Nestel 1869). – C. avellana f. pendula (Nestel) Dippel, Handbuch der Laubholzkunde 2: 128 ( Dippel 1891) [“1892”]. – Original citation: “wurde vor einer Reihe von Herrn Niessing in einem Walde seiner Heimat entdeckt, und später als diese merkwürdige, natürliche Spielart für ihn als Gärtner erhöhtes Interesse erhielt, durch Uebertragung von Pfropfreisen und durch Ableger festgehalten.” – Type: not localized. – Note: Corylus avellana var. pendula is a formal taxonomical name for a cultivar with over-hanging branches, best treated as C. avellana ‘Pendula’. This garden variety was brought into cultivation by Niessing ( Nestel 1869) and presented for the first time at the World Exhibition in Paris in 1867 ( Goeschke 1887: 49).

2ah. Corylus avellana ‘ Urticifolia ’

C. avellana [unranked] urticifolia Nois., Manuel Complet du Jardinier, Maraicher, Pépiniériste, Botaniste, Fleuriste et Paysagiste 2: 464 ( Noisette 1825) [“urticaefolia”]. – C. urticifolia hort. ex Loudon, Arboretum et Fruticetum Britannicum 3: 2017 ( Loudon 1838) nom. inval. pro syn. – C. avellana var. urticifolia (Nois.) A.DC., Prodromus Systematis Naturalis Regni Vegetabilis 16(2): 131 ( Candolle 1864). – C. urticifolia (Nois.) Dippel, Handbuch der Laubholzkunde 2: 128 ( Dippel 1891) [“1892”]. – Original citation: “Nous l’avons vu chez M. le comte Montmorenci à Montgeron [ France]”. – Type: not localized. – Note: none of the later users of the epithet “ urticifolia ” refer to Noisette, who called it “espèce” and “variété” with the name “ C. urticaefolia ” (thus unranked). However, this leaf shape mutation apparently occurs spontaneously in the wild ( Franz 1992). Mehlenbacher & Smith (1995) found the trait to be encoded by a recessive gene. It is thus likely that there are multiple origins of cultivars with the variety name ‘Urticifolia’ (and C. avellana var. heterophylla Loudon , C. laciniata hort. ex Burchardt , and C. avellana var. quercifolia Booth et al. ex G.Kirchn. ). Nevertheless, they all refer to a horticultural variety with the same mutation (therefore Art. 41.4 applies, McNeill et al. 2012), which is to be treated as C. avellana ‘Urticifolia’ as the earliest available name (Art. 29.1, Brickell et al. 2009).

C. avellana var. heterophylla Loudon, Arboretum et Fruticetum Britannicum 3: 2017 ( Loudon 1838). – C. heterophylla Lodd., Catalogue of Plants ed. 16: [page unknown] ( Loddiges 1836) nom. nud. – C. avellana f. heterophylla (Loudon) Rehder , Bibliography of Cultivated Trees and Shrubs Hardy in the Cooler Temperate Regions of the Northern Hemisphere: 110 ( Rehder 1949). – Type: not localized. – Note: the epithet heterophylla is problematic in Corylus . At the rank of a variety (and forma), it was formally used for a garden cultivar ( C. avellana ‘Urticifolia’), whereas in the rank of a species, it was only used as a mere name without description for that cultivar (nom. nud.). However, there is a species, C. heterophylla Fisch. ex. Trautv., from East Asia that must not be confused with with ornamental plant with narrow, deeply incised and double-serrate leaves. As neither Trautvetter nor Fischer referred to a cultivar, but a Siberian wild species, their name is not to be treated as a new combination (Art. 41.4, McNeill et al. 2012). The oldest epithet for the deeply incised doubleserrate C. avellana is urticifolia , C. avellana [unranked] urticifolia Nois. ( Noisette 1825) , hence this cultivar should be called C. avellana ‘Urticifolia’.

C. laciniata hort. ex Burchardt, Verhandlungen des Vereins zu Beförderung des Gartenbaues in den Königlich Preussischen Staaten 15: 84 ( Burchardt 1841). – C. avellana f. laciniata (Burchardt) Döll, Rheinische Flora : 273 ( Döll 1843). – C. avellana var. laciniata (Burchardt) G.Kirchn., Arboretum Muscaviense : 670 ( Petzold & Kirchner 1864). – Original citation: “Ich habe meinen Stamm von den Herren Gebrüdern Baumann, die ihn von einem ihrer Reisenden aus dem südlichen Frankreich als Betula laciniata ohne Angabe des Orts erhalten hatten.” – Type: most likely destroyed. – Note: there is a report that a nut collection (‘Nusskabinet’) existed, but it was most likely destroyed ( Anonymous 1854) by Burchardt’s elder son ( Müller 1861). Therefore, upon publication, there was original material, but was subsequently lost. The name laciniata is a garden name that was taken up several times independently (see C. avellana f. laciniata and C. avellana var. laciniata ). The oldest publication is by Theodor Heinrich Otto Burchardt (13 Dec. 1771 – 6 Feb. 1853, cf. Müller 1861), justice councellor (‘Justizrat’) from Landsberg a. d. Warthe (now Gorzów Wielkopolski, Poland), who described it as a new species. He mentioned that he had the stock from the Pépinières Baumann from Bollwiller (Alsace, France), a then famous seed seller, who had received the material from Southern France under the name Betula laciniata . Burchardt mentioned that the plant is also to be found in the catalog of the Frères Audibert ( Audibert 1831 –1832), where it is listed without a description. The name, however, had already been used in seed catalogs before ( Dailledouze & Dailledouze 1828).Although neither Döll nor Kirchner explicitly referred to Burchardt, they referred to the same mutation, and their names are thus to be treated as new combinations (Art. 41.4, McNeill et al. 2012).

C. serenyiana Pluskal, Oesterreichisches Botanisches Wochenblatt 2: 394 ( Pluskal 1852). – C. avellana var. serenyiana (Pluskal) Pluskal, Verhandlungen des Zoologisch-Botanischen Vereins in Wien 3 (2): 22 ( Pluskal 1853). – Original citation: “an dem Ufer eines Baches bei Lomnitz [Lomnice u Tišnova, Czech Republic]”. – Type: not localized. – Note: Pluskal mentioned that his plan to describe his name was highly disputed since it closely corresponded to C. avellana var. laciniata , but he insisted on describing it as a new species as he found it in the wild and reported it as new to Moravia.

C. avellana var. quercifolia Booth et al. ex G.Kirchn., Arboretum Muscaviense : 670 ( Petzold & Kirchner 1864). – C. quercifolia hort. ex A.DC., Prodromus Systematis Naturalis Regni Vegetabilis 16 (2): 131 ( Candolle 1864) nom. inval. pro syn. – Note: Rehder (1949) listed this garden variety as a synonym to his C. avellana f. heterophylla .

C. avellana var. incisa André , L’art des jardins: 574 ( André 1879). – Type: not localized.

C. avellana var. pinnatifida Plan. nom. nud. in sched. –Associate material: Sweden, Östergötland, Regna, s. coll., s.n. (L1559661!) [N.J. Andersson ex S, pers. com.]; Sweden, Östergötland, Regna, [misit Jul. 1867], s. coll, s.n. (K!, MANCH!) [F. Ahlberg, pers. com.]; Sweden, prope Regna Ostergothia, 12 Jul. 1867, E. Rathsman s.n. (BM! K!, K!, K!, LD1790934, MANCH!, OHN135122); Sweden, OG, Regna, 1 Jun. 1865, E. Rathsman s.n. (BM!, LD1798977); Sweden, Ostergothia, Regna, Aug. 1873, A. Magnusson s.n. (P06809852!). – Note: this name is found on Swedish specimens of C. avellana ‘Urticifolia’. The name is apparently by J.E. Planander, but the present authors are not aware of a valid publication.

2ai. Corylus avellana ‘ Variegata ’

C. avellana var. variegata A.DC., Prodromus Systematis Naturalis Regni Vegetabilis 16 (2): 131 ( Candolle 1864). – C. avellana f. variegata (A.DC.) Dippel, Handbuch der Laubholzkunde 2: 128 ( Dippel 1891) [“1892”]. – Type: not localized. – Note: Candolle summarized with this name C. avellana cultivars with white, yellow or red-variegated leaves.

2b. Corylus avellana var. pontica (K.Koch) H.J.P.Winkl.

Das Pflanzenreich IV 61 (Heft 19): 47 ( Winkler 1904). – C. pontica K.Koch , Linnaea 22: 329 ( Koch 1849). – Original citation: “Auf der Nordseite des pontischen Gebirges auf Augitporphyr bis 2500’ Höhe.” – Type: not localized. – Note: Corylus avellana var. pontica is recognized by Flora of the USSR ( Bobrov 1936a) and World Checklist and Bibliography of Fagales ( Govaerts & Frodin 1998) . It apparently differs from C. avellana var. avellana by double-serrate bracts that surpass the nut and are apically prominently veined. This morphology is also widely found elsewhere and particularly common in cultivars. Therefore Kosenko (2002) hypothesized that the domesticated hazel might be a hybrid involving or directly selected from C. avellana var. pontica . The eastern origin of hazel cultivation seems to find support in the ancient Roman name“ nux pontica ”, supposedly first introduced from Pontus (Pliny the Elder 77–79). Koch neither mentions the Romans, nor any cultivars. Koch mentions that the nuts resemble those of C. colurna and refers to a wild collection. However, given that hazels freely intercross within the subsections ( Erdoğan 1999; Erdoğan & Mehlenbacher 2000) and that hazels have been bred for centuries, the persistence of a “pure” genotype “ var. pontica ” in the wild (if it ever existed) is more than doubtful.

C. pontica var. glandulifera K.Koch , Linnaea 22: 330 ( Koch 1849). – C. colurna var. glandulifera (K.Koch) A.DC., Prodromus Systematis Naturalis Regni Vegetabilis 16 (2): 132 ( Candolle 1864). – Original citation: no collections cited. – Type: not localized.

C. imeretica Kem. -Nath., Trudy Tbilisskogo Botaniceskogo Instituta 1: 111 ( Kemularia-Nathadze 1933). – Type: Georgia, prov. Kutais, distr. Schorapani, fauces fl. Kvirila, prope urb. Tschiathura ad rupes calcareas, 26. Jul. 1930, L.M. Kemularia-Nathadze s.n. (syn-: LE [photo at E, K], TBI1024989!); Georgia, prov. Kutais, distr. Letschchum, fauc. fl. Rioni, prope pag. Atscharis-chidi ad rupes calcareas, 29 Jul. 1929, L.M. Kemularia-Nathadze s.n. (syn-: not localized). – Note: Corylus imeretica was synonymized under C. avellana var. pontica by Rehder (1949).