(79–80) Request for binding decisions on the descriptive statements associated with Polypodium contaminans and Alsophila brunoniana (Cyatheaceae)

Abstract

In two recent accounts of the fern family Cyatheaceae in India (see below) two names that appeared in Wallich's A numerical list of dried specimens of plants and that previous authors had considered to be nomina nuda were considered to be validly published. As acceptance of these names questions the nature of the requirement for a “description” (Art. 38.1(a) of the ICN; Turland & al. in Regnum Veg. 159. 2018), and hence has wider implications, a binding decision on their valid publication is needed. (79) Polypodium contaminans Wall., Numer. List: No. 320. 1829 Fraser-Jenkins & al. (Annot. Checkl. Indian Pterid. 1: 122. 2016) considered Polypodium contaminans Wall. (Numer. List: No. 320. 1829) to be a validly published name and treated Alsophila contaminans, published by Hooker (Sp. Fil. 1: 52. 1844), not as the first valid publication of a name with the epithet “contaminans”, but as a new combination based on Wallich's name. Wallich (l.c.) stated only “320 Polypod. contaminans Wall. in Herb. 1823 / Polypod. latebroso, Wall. valde affine / Arbor – Penang”, i.e., the nature of the similarity to P. latebrosum (also a tree fern) is not mentioned, and the only descriptive material is that the species is a tree. The term “diagnosis” is defined in Art. 38.2 of the ICN as “a statement of that which in the opinion of its author distinguishes a taxon from other taxa”. However, the descriptive statement associated with Polypodium contaminans cannot explain how to distinguish this species from others and it is certainly not acceptable as a diagnosis, and also, I believe, should not be considered a description satisfying the requirement of Art. 38.1(a). Polypodium contaminans Wall. was accepted as validly published by Kholia & Sinha (in Indian J. Forest. 39: 401–405. 2016), but Hassler & Schmitt (Checkl. Ferns Lycophytes World, https://worldplants.webarchiv.kit.edu/ferns/, last accessed 31 May 2019) did not accept the validity of Wallich's name. The species is currently known as Sphaeropteris glauca (Blume) R.M. Tryon (in Contr. Gray Herb. 200: 21. 1970), based on Chnoophora glauca Blume (Enum. Pl. Javae 2: 243. 1828), or, in Cyathea, as C. contaminans (Wall. ex Hook.) Copel. (in Philipp. J. Sci., C 4: 60. 1909), based on Alsophila contaminans Wall. ex Hook. (Sp. Fil. 1: 52. 1844), this author citation being the only nomenclatural matter affected by the issue of valid publication of Wallich's name. (80) Alsophila brunoniana Wall., Numer. List: No. 7073. 1832 Fraser-Jenkins & al. (Ferns Fern-allies Nepal 1: 154. 2015, l.c. 2016: 125), accepted Alsophila brunoniana Wall. (Numer. List No. 7073. 1832) as a validly published name as Wallich included the following statement in the protologue: “Alsophila Brunoniana Wall. (Caet. spec. n. 180, 318, 320, 329? 336 et 385) / Mt Sillet W.G. (Hujus filicis arborea caudex ped. 45 altus ab ampliss. Procuratione Brit. Ind. Orient Museum Britanico anno 1831 donatio).” Wallich thus reported that this tree fern was represented by the trunk of a tree about 45 feet or more in height, collected by William Gomez from “Mt Sillet” (the Khasi Hills in Assam, India; see http://wallich.rbge.info/node/17499) and donated to the British Museum (now Natural History Museum, London) in 1831. However, a trunk 45 feet (13.7 m) tall is not a diagnostic feature at species level as Alsophila spinulosa (Wall. ex Hook.) R.M. Tryon (l.c.: 32), for example, produces a trunk 5–15 m or sometimes more than 20 m (Zhang & Nishida in Fl. China 2–3: 136. 2013). Wallich's descriptive statement, i.e., length of trunk does not explain how to distinguish Alsophila brunoniana from other species and is not, therefore, acceptable as a diagnosis and, in my view, insufficient as a description. This species is currently known as Sphaeropteris brunoniana (Wall. ex Hook.) R.M. Tryon (l.c.: 21) or, in Cyathea, as C. brunoniana (Wall. ex Hook.) C.B. Clarke & Baker in J. Linn. Soc. Bot. 24: 409. 1888). The author citations given assume that Alsophila brunoniana was not validly published by Wallich, but by Hooker (l.c.). Nevertheless, it is also apparently arguable that these two descriptive statements by Wallich satisfy the requirement for a “description” as set out in Art. 38.1(a). Consequently, I request a binding decision on the descriptive statements associated with these two names. JM, https://orcid.org/0000-0001-6127-2737 I sincerely thank Prof. J. McNeill (E) for critical reading, editing and improving this request.