1. Corylus americana Walter

Flora Caroliniana: 236 (Walter 1788). – Type: USA, Georgia, Taccoa, Herbersham Co., 1200 ft., 17–20 Aug. 1895, J.K. Small s.n. (neo-, designated by Ward (2007: 1099) and here corrected: A00247927!; isoneo-: NY01185413!). – Note: Walter’s Herbarium was in the hands of John Fraser’s family and later sold to BM (Stafleu & Cowan 1976 –1988), but apparently lost. Ward therefore designated the neotype at the Gray Herbarium (GH), but the specimen is actually part of the collection of Arnold Arboretum (A). As both collections are housed in the same building, we correct Ward’s minor mistake. There is no type locality mentioned in the protologue. The name is recognized as a species in the Flora of North America (Furlow 1997) and World Checklist and Bibliography of Fagales (Govaerts & Frodin 1998) .

C. humilis Willd., Enumeratio Plantarum Horti Regii Berolinensis: 983 (Willdenow 1809). – C. nana Bosc, Encyclopédie Méthodique, Agriculture 7: 597 (Tessier et al. 1821) nom. nud. (though it would also be illegitimate due to C. nana Tourrette & Rozier). – C. pumila Spach, Annales des Sciences naturelles, seconde série – Botanique 16: 104 (Spach 1841) nom. nud. – C. americana [unranked] humilis (Willd.) Dippel, Handbuch der Laubholzkunde 2: 132 (Dippel 1891) [“1892”]. – C. americana f. humilis (Willd.) Schelle, Handbuch der Laubholzbenennung: 50 (Beissner et al. 1903). – Type: USA, “Noveboraco” (New York), s. coll. in Herb. C.L. von Willdenow s.n. (lecto-, designated here: B-W 17705!). – Note: Willdenow cited a description by Wangenheim (1787: 88), in which Wangenheim mentioned that the American Hazel was growing rather smallish (8 to 10 feet). Initially, Willdenow (1805: 471) provided the phrase name Corylus americana humilis, but without recognizing it as a distinct taxon. In 1809, Willdenow recognized it as a separate species, C. humilis, which he considered as close to C. americana, but with leaves like those of C. avellana . Corylus pumila mentioned by Spach (1841) is supposed to be based on Willdenow. However, to our knowledge there is no Willdenow name “ Corylus pumila ”. Possibly, Spach’s epithet was supposed to be a nom. nov. Another name was published by Bosc in the agricultural vol. 7 of Lamarck’s Encyclopédie Méthodique (Tessier et al. 1821). There, Bosc mentioned a C. nana from Eastern North America, supposedly based on Willdenow. More likely, the name was confused, because Willdenow called his dwarf hazel C. humilis, besides that “ C. nana ” had been published before for a low-growing C. colurna (La Tourrette & Rozier 1787) . The lectotype is taken from Willdenow’s own collection. Additional original material might exist in Wangenheim’s collection, which was at least partly handed over to Schreber (Zuccarini 1833), and might be housed in M.

C. americana var. missouriensis A.DC., Prodromus Systematis Naturalis Regni Vegetabilis 16 (2): 132 (Candolle 1864). – C. americana f. missouriensis (A.DC.) Fernald, Rhodora 34: 96 (Fernald 1932). – Type: USA, Missouri, Saint-Louis, N. Riehl 91 (holo-: G00418162!; iso-: BR0000013516888!, MO1181611!).

C. serotina G.Kirchn., Arboretum Muscaviense: 672 (Petzold & Kirchner 1864). – Type: not localized, from cultivation from Königliche Landesbaumschule Sanssouci [Potsdam, Germany]. – Note: Petzold was in contact to Schlechtendal in HAL (Stafleu & Cowan 1976 –1988), possibly original material may be found there.

C. virginiana hort., Die Haselnuss: 90 (Goeschke 1887) nom. nud. – C. virginiana hort. ex Dippel, Handbuch der Laubholzkunde 2: 132 (Dippel 1891) [“1892”] nom. inval. pro syn.

C. calyculata Dippel, Handbuch der Laubholzkunde 2: 132 (Dippel 1891) [“1892”]. – C. americana [unranked] calyculata (Dippel) Schelle, Handbuch der Laubholzbenennung: 50 (Beissner et al. 1903). – C. americana var. calyculata (Dippel) H.J.P.Winkl., Das Pflanzenreich IV 61 (Heft 19): 48 (Winkler 1904). – Original citation: “Diese von Göschke, dem wir unsere Pflanze verdanken (...)” – Type: not localized [from cultivation by Goeschke]. – Note: this is supposed to be a weakly growing plant in contrast to the larger C. americana, very likely the same that Willdenow described as C. humilis Willd.

C. americana var. altior Farw., Report of the Michigan Academy of Science 17: 168 (Farwell 1915). – Type: USA, Michigan, Algonac, 7 Jul. 1912, O.A. Farwell 2822 (syn-: BLH0000405); ibid., 8 Sep. 1912, O.A. Farwell 3154 (syn-: BLH0000408, BLH0000409, BLH0000410); Canada, Ontario, Stoney Creek, 27 Oct. 1912, O.A. Farwell 3266 (syn-: BLH0000406, BLH0000411).

C. americana var. indehiscens E.J.Palmer & Steyerm., Annals of the Missouri Botanical Garden 22: 516 (Palmer & Steyermark 1935). – Type: USA, Missouri, Greenwood, Jackson Co., 5 Sep. 1924, B.F. Bush 10332 (holo-: A00033774!; iso-: K!, MIN1000722). – Additional type material: ibid., E.J. Palmer 26035 (para-: A); ibid., Arkansas, Martinsville, Faulkner Co., 13 Oct. 1924, E.J. Palmer 26537 (para-: A); ibid., Hot Springs, Garland Co., 11 Oct. 1925, E.J. Palmer 29160 (para-: A); ibid., North Carolina, 19 Sep. 1897, Biltmore Herb. 1244b (isopara-: WU!).