Research Article |
Corresponding author: Grzegorz J. Wolski ( grzegorz.wolski@biol.uni.lodz.pl ) Academic editor: Matt von Konrat
© 2020 Grzegorz J. Wolski, Anna Faltyn-Parzymska, Jarosław Proćków.
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.
Citation:
Wolski GJ, Faltyn-Parzymska A, Proćków J (2020) Lectotypification of the name Stereodon nemoralis Mitt. (Plagiotheciaceae), a basionym of Plagiothecium nemorale (Mitt.) A. Jaeger. PhytoKeys 155: 141-153. https://doi.org/10.3897/phytokeys.155.51469
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In 1859, William Mitten described Stereodon nemoralis (≡ Plagiothecium nemorale) based on the gathering of Sir J.D. Hooker from India. However, the protologue did not indicate any specific specimen or illustration. For the past 50 years, the original material (NY 913349) deposited at the NY Herbarium has been considered as the holotype. However, this assumption has since been found to be incorrect, because in the Herbarium of The Natural History Museum exists other original material of this species (BM 1030713), collected by Hooker. In addition, the specimen from NY Herbarium is in poor condition and its most important diagnostic characters are not visible. In contrast, the material from BM Herbarium is in very good condition, and therefore it is herein designated as the lectotype. Also, the paper describes the resolution of this type, a process complicated by changes that had occurred in the provisions of subsequent botanical Codes.
Codes of Botanical Nomenclature, Hooker collection, India, Mitten collection, nomenclatural types, Plagiothecium, Stereodon, typification
During his travels around India (between 1847–1851), staying from 20 to 24 May 1848 on Mount Tonglo (alt. 3036 m) in the Singalila Range in the Eastern Himalayas of Sikkim Sir Joseph Dalton Hooker collected many specimens of mosses (
The first set of specimens is preserved in the Hooker’s Herbarium which was acquired in 1867 by Kew Gardens (K), but after World War II the bryophyte collection in K, thanks to a decision of the British government, was transferred to the British Museum (BM). Mitten retained many duplicates in his private herbarium which after his death in 1903 was bought by the New York Botanical Garden (NY).
Stereodon nemoralis was incorporated into the genus Plagiothecium by Augusto Jaeger in 1878, and its name changed to Plagiothecium nemorale (Mitt.) A. Jaeger (
Plagiothecium nemorale has long been a neglected species, until it was resurrected from obsolescence by
After Mitten’s death in 1906, his entire herbarium was purchased by the NY Herbarium, and that is where most of the types of the species described by Mitten can currently be found. In addition, according to
A number of other herbaria from around the world were also searched, as well as various virtual databases with a global reach, such as JSTOR Global Plants, GBIF, Tropicos, INCT – the Virtual Herbarium of Flora and Fungi, the Chinese Virtual Herbarium and the Consortium of North American Bryophyte Herbaria (CNABH). A list of all checked herbaria is available on request directly from the first author.
In 2016 and 2018, during the taxonomic revision of Plagiothecium nemorale sensu lato, its type specimens were examined. It was found that the NY Herbarium included two specimens with separate numbers on one herbarium sheet (Fig.
The information given on the herbarium sheet, comprising the name of the collector, the description of the location, and even the substratum on which the specimen grew, i.e. the fern visible in the picture, is the same as in the protologue (
The herbarium sheet also included a label with the inscription: “Syntype of: Stereodon nemoralis Mitt. J. Linn. Soc. Bot. Supp. 1: 104. 1859 ≡ Plagiothecium sylvaticum (Brid.) B.S.G. cf. Card.”. It was not possible to determine when the label had been stuck to the herbarium sheet: it could have been a few years or several decades previously. Nevertheless, it was reported to have been placed there by the NY Herbarium staff by mistake (Herbarium staff, pers. comm.). However, this appeared to be a mistake only until July 2011, when the Vienna Code ceased to apply (
After careful analysis of the material, it can be said that the available material at NY (NY 913349) differs significantly from that which was photographed and published by Iwatsuki in 1970. It is easy to assess the changes in the amount of available material (Figs
As a part of the taxonomic revision of P. nemorale, efforts were made to find the entire original material and the species names now considered to be synonyms of this species. In the case of S. nemoralis, this also concerned specimens collected by Hooker from India or other materials from Mitten’s collections. A global search of herbaria revealed the existence of specimen BM 1030713, labelled as an isotype of S. nemoralis (Fig.
This conclusion is supported by the following passage from Page 4 of Mitten’s book (1859): “The materials from the present enumeration have been derived from the collections (…), but more especially from those made by (…) Dr J.D. Hooker in the Sikkim-Himalaya and East Nepal (…). (…), the entire extensive collections of (…) Dr J.D. Hooker were entrusted to the author for segregation and distribution.”
In addition, Article 9.1 of the Shenzhen Code (
Although the protologue by Mitten did not indicate the specimen or the illustration as a type according to Article 9.1 (a) of the Shenzhen Code (
This specimen in NY has been considered as a holotype by a number of researchers (see:
Specimen NY 913349 cannot be recognised as a holotype based on Rec. 9A.4 of the Vienna Code posted above (
In the protologue of S. nemoralis, not only did Mitten not refer to any single specimen, but also he explicitly stated that he was in possession of all materials acquired by J.D. Hooker and was responsible for their “segregation and distribution” (
Due to the bad condition of the specimen from the NY Herbarium (NY 913349) and on the basis of the following five Articles of the Shenzhen Code (
The specimen from the BM Herbarium (BM 1030713) is a medium-sized plant, light green to yellowish, without metallic luster. Stems to 2 cm long, complanate-foliate, in cross-section rounded, with a diameter of 300–350 µm, central strand developed, epidermal cells 8–15 × 15–25 µm, parenchyma thin-walled, 20–50 × 11–35 µm; leaves gently concave, symmetrical, ovate, in dry condition shrunken, those from the middle of the stem 2.2–2.4 mm long, and the width measured at the widest point 1.0–1.3 mm; the apex straight, denticulate, acute, apiculate; two costae, extending almost to ½ leaf length, reaching 0.50–0.60 mm; hexagonal and narrowly-hexagonal cells in regular transverse rows, areolation very lax; cells reach 55–96 × 15–18 µm at the apex, 75–97 × 16–20 µm at mid-leaf, and 74–125 × 14–20 µm at the lower part of the leaf; decurrencies of 3 rows of rectangular cells, 25–35 × 20–30 µm (Fig.
Throughout its range in Eurasia (
These features also distinguish very well P. nemorale from other similar or closely related species. For example, resurrected recently P. longisetum Lindb. is characterised by: asymmetrical leaves, a not denticulate leaf apex, and extended hexagonal leaf cells whose length is in the range from 100 to 150 µm (
Formal typification may be summarised thus:
Stereodon nemoralis Mitt., Journ. Linn. Soc. Bot. Suppl. 1: 104 (1859) ≡ Plagiothecium nemorale (Mitt.) A. Jaeger, Ber. S. Gall. Naturw. Ges. 1876–1877: 451 (1878) ≡ P. silvaticum var. nemorale (Mitt.) Paris, Index Bryol.: 967 (1898). Type citation: Hab. In Himalayae orient. reg. temp., Sikkim, in monte Tonglo (ad radicem filicis cujusdam), J. D. Hooker ! Lectotype (designated here): “Herb. Ind Or Hook. Fil. & Thomson Stereodon nemorale m. Hab. Sikkim, Tonglo Regio temp. Alt. − J. D. H.” − BM 1030713!: isolectotype: NY 913349!
We are grateful to Professor John McNeill from Royal Botanic Garden Edinburgh, Scotland and to Professor Nicholas Turland from Botanischer Garten und Botanisches Museum Berlin, Freie Universität Berlin, Germany for their priceless comments and remarks which contributed to this article. In addition, we are grateful to the curators of the BM Herbarium, to Professor Leonard T. Ellis from the Natural History Museum, U.K. and to Laura Briscoe, MSc, Collections Manager of the Cryptogamic Herbarium NY (New York Botanical Garden, USA) for the loan of type specimens. Furthermore, we are grateful to Professor William R. Buck and Laura Briscoe MSc (NY), for all consultations on the S. nemoralis type, and also, we would like to thank very much three reviewers of the manuscript for their helpful comments, suggestions and text corrections.