PhytoKeys 34: 15–17, doi: 10.3897/phytokeys.34.7040
The correct name for a subspecies of Oenothera fruticosa L. (Onagraceae)
Warren L. Wagner 1
1 Department of Botany, MRC-166, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, Washington, DC 20013-7012, USA

Corresponding author: Warren L. Wagner (

Academic editor: H. Schaefer

received 14 January 2014 | accepted 17 January 2014 | Published 31 January 2014

(C) 2014 Warren L. Wagner. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

For reference, use of the paginated PDF or printed version of this article is recommended.

Citation: Wagner WL (2013) The correct name for a subspecies of Oenothera fruticosa L. (Onagraceae). PhytoKeys 34: 15–17. doi: 10.3897/phytokeys.34.7040


In 1978 when Straley adopted the name Oenothera fruticosa L. subsp. glauca (Michx.) Straley for one of the two recognized subspecies of O. fruticosa it was the correct name for this taxon; however, since that time the botanical code has changed so that now an autonym is treated as having priority over the name or names of the same date and rank that established it. This change means that since 1981 O. fruticosa subsp. glauca was no longer the correct name. The appropriate combination for it is made here as O. fruticosa L. subsp. tetragona (Roth) W.L. Wagner. Original material for the basionym, O. tetragona, is no longer extant so a neotype is designated.


Oenothera fruticosa, O. tetragona, O. glauca, nomenclature


The superfluous nature of the combination Oenothera fruticosa subsp. glauca (Michx.) Straley (1978) was brought to my attention by John Wiersema so that the nomenclature could be corrected in advance of the forthcoming treatment of Oenothera in the Flora of North America.

In a revision of Oenothera sect. Kneiffia (Straley 1978) a common eastern North American species widely cultivated in gardens, Oenothera fruticosa, was broadly delimited to include in synonymy a number of names previously recognized as distinct species. Oenothera fruticosa was subdivided into two widespread subspecies with subsp. fruticosa occurring at lower elevations and having a more southerly geographic distribution and subsp. glauca occurring in more northerly areas and at higher elevations. In 1978 Straley made the new combination Oenothera fruticosa subsp. glauca for the more northerly subspecies, based on Oenothera glauca Michx. and including among its synonyms Oenothera tetragona subsp. glauca (Roth) Munz and Oenothera tetragona Roth. In 1978 Straley’s new combination was the correct name for the taxon; however, since that time the botanical code of nomenclature has changed so that an autonym is treated as having priority over the name or names of the same date and rank that established it. This change means that since 1981, when this rule was added (Greuter 1981: 910, note 7), Oenothera fruticosa subsp. glauca was no longer the correct name for this taxon.

This rule is now Art. 11.6 of the current code of nomenclature (McNeill et al. 2012), and it dictates that the autonym, Oenothera tetragona subsp. tetragona, has priority over the name that created it, Oenothera tetragona subsp. glauca. Since the type of Oenothera tetragona, which is necessarily also the type of Oenothera tetragona subsp. tetragona (Art. 7.6), was definitely included by Straley in the synonymy of Oenothera fruticosa subsp. glauca, the correct name for this taxon must be the combination Oenothera fruticosa subsp. tetragona, which has not been previously made. The name Oenothera fruticosa subsp. glauca, although nomenclaturally superfluous (Art. 52.1), is not illegitimate (because it has a basionym; Art. 52.3) and is here placed into synonymy.

Oenothera fruticosa tetragona (Roth) W.L. Wagner, comb. nov.


Oenothera tetragona Roth, Catal. Bot. 2: 39. 1800.

Type. Grown in the garden of Wilhelm Koch, at Gnadau, near Barby, Germany, of American origin; no extant material located. Pennsylvania. Lancaster Co.: between Churchtown Rd. and Beartown, 6 September 1892, A.A. Heller 549 (neotype, here designated: US-58278; isoneotypes: G-Bois, G, MO, NY). Munz (1937) apparently saw the original type material in B, stating “Ex horto meo Vegesackii, 1799, Oe, tetragona, Herb. A. W. Roth.” I contacted Robert Vogt at Berlin and there is currently no extant original material; however, he located a specimen grown from seeds provided by A. W. Roth “e semin. Rothianis in h. bot. Wratislav. colui 1823, “ but there is no way to clearly connect this material with the original material used when Roth described the species. I have here selected a neotype that fits Roth’s description and was considered to represent this entity in its narrowest interpretation. It was annotated by Munz for his 1937 revision and also by Straley for his 1978 revision.


Oenothera glauca Michx., Fl. Bor.-Amer. (Michaux) 1: 224. 1803. Kneiffia glauca (Michx.) Spach, Hist. Nat. Veg. Phan. 4: 374. 1835. Oenothera fruticosa L. var. glauca (Michx.) H. Lév., Monogr. Onothera 107. 1902. Oenothera tetragona Roth subsp. glauca (Michx.) Munz, N. Amer. Fl., ser. 2, 5: 91. 1965. Oenothera fruticosa L. subsp. glauca (Michx.) Straley, Ann. Missouri Bot. Gard. 64: 403. 1978 [“1977”; published 26 May 1978].

Type. Hab. in sylvis remotis et occidentalibus flumini Mississippi confinibus, versus regionem Illinoensium, 1787 or 1789, A. Michaux s.n. (holotype: P, photograph GH; isotype: P). According to Straley (1978) the type is labeled “Ouest de Ohio, Route aux Illinois, ” but the plant is presumably from the southern Appalachians, in the Carolinas or Virginia where Michaux collected in June and July of 1787 and 1789.


I thank John Wiersema for bringing this problem to my attention. I also appreciate the help in the search at Berlin of original material of Oenothera tetragona by Robert Vogt and for providing the image of the 1823 specimen by Ulrike Starck. I thank Fred Barrie and Nick Turland for the careful and helpful review of the manuscript.

Greuter W (1981) XIII International Botanical Congress: mail vote and final Congress action on nomenclature proposals. Taxon 30: 904-911.
McNeill J, Barrie FR, Buck WR, Demoulin V, Greuter W, Hawksworth DL, Herendeen PS, Knapp S, Marhold K, Prado J, Prud’homme van Reine WF, Smith GF, Wiersema JH, Turland NJ (Eds) (2012) International Code of Nomenclature for algae, fungi, and plants (Melbourne Code) adopted by the Eighteenth International Botanical Congress Melbourne, Australia, July 2011. Koeltz Scientific Books, Königstein, Germany. [Regnum Veg. 154].
Munz PA (1937) Studies in Onagraceae X. The subgenus Kneiffia. Bull. Torrey Bot. Club 64: 287-306. doi: 10.2307/2480888
Straley GB (1978) [“1977”] Systematics of Oenothera sect. Kneiffia (Onagraceae). Ann. Missouri Bot. Gard. 64: 381-424. [published 26 May 1978] doi: 10.2307/2395256