Chenopodium divaricatum, Andrzejowski, 1862

Mosyakin, Sergei L., 2017, Notes on taxonomy and nomenclature of Chenopodium acerifolium and C. betaceum (C. strictum auct.) (Chenopodiaceae), Phytotaxa 324 (2), pp. 139-154 : 149

Chenopodium divaricatum : still in the mist

The invalid name “ Chenopodium divaricatum ” (nomen nudum, Art. 38.1 of ICN, McNeill et al. 2012) was mentioned by Fischer already in 1808 and 1812, in both cases without any description or diagnosis ( Fischer 1808: 23; Fischer 1812: 15). Thus, the name C. divaricatum proposed by Andrzejowski is valid and legitimate.

The name Chenopodium divaricatum was rarely mentioned in botanical publications,except for some nomenclatural lists (e.g., Trautvetter 1984). No opinion on its identity was expressed by other authors except Iljin (1952), who listed that name in synonymy of his “ C. serotinum L.”, which was in fact C. ficifolium Smith. However , the original plants of Andrzejowski are definitely not conspecific with C. ficifolium ; they evidently belong to the C. album aggregate.

The two currently available specimens have a few remaining cauline leaves and fruits mostly fallen out, which hampers their morphology-based identification. Morphologically the plants resemble some forms of the C. album aggregate; the specimens such as those were reported earlier as C. laciniatum Murr [1903: 9 , nom. illeg., non Thunb. nec Roxb. (Art. 53.1 of ICN, McNeill et al. 2012); see Dvořák 1990], for which the replacement name C. dvorakianum Mosyakin (1995: 459) was proposed. However, it is also possible that the specimen KW-001002777 is related to or even conspecific with C. suecicum . The plant on the sheet KW-001002778 is morphologically similar to C. betaceum (but the diagnostic cauline leaves are absent). Further comparative micromorphological and probably also molecular studies are needed to clarify the identity of the third species of Chenopodium described by Andrzejowski. The lectotype of this species is designated below.