(2932) Proposal to reject the name <i>Callitriche foliosa</i> ( <i>Plantaginaceae</i> )

(2932) Callitriche foliosa Raf. in Med. Repos., ser. 2, 5: 354. Mai 1808 [Angiosp.: Callitrich. / Plantagin.], nom. rej. prop. Lectotypus (hic designatus): [U.S.A., New York or Vermont], “ad ripam meridionalem Lacûs Champlain”, Michaux (P barcode P00322496!). This proposal is part of a complete revision the L. names published treated by Constantine Samuel Rafinesque (1783–1840) (Hassemer & Lansdown, prep.). (in 1808) was validly through statement “C. autumnalis do”, referring to treatment C. (Fl. Suec., ed. 2: 2. 1755) Bor.-Amer. 1: 1803). Since no further information provided protologue, determination identity name depends on an investigation Michaux's (l.c.) autumnalis. did express doubt regarding species question, use question mark (“autumnalis?”). He scant morphological (“foliis omnibus linearibus, emarginatis, approximatis”) and provenance as lacus Champlain”. Lake Champlain located between American states Vermont, just extending into southern Canadian province Québec. also admitted that he not see flowers (“Florentem non vidi”). No specimens illustrations were cited. synonym hermaphroditica (Cent. Pl. 31. 1755), common widely distributed temperate boreal areas Northern Hemisphere (Fassett Rhodora 53: 215–219, t. 1175[24]. 1951; Eur.: 124–130. 2008; Hassemer Lansdown Phytotaxa 547: 296, 298. 2022). It should be noted that, despite having frequently been considered superfluous illegitimate (e.g., Jarvis, Order out Chaos: 375–376. 2007), phrase-name linearibus apice bifidis, floribus hermaphroditis”) exactly same bifidis”); hence, (Art. 52.3 ICN; Turland al. Regnum Veg. 159. 2018). Nevertheless, fact determined (although with doubts) element upon which based his foliosa, latter uncritically linked hermaphroditica, because are homotypic, especially because, explained above, himself expressed plants called The for “Callitriche autumnalis?” far from sufficient link entity single species. However, we have able locate specimen (P00322496), originally Herbarium, unquestionably original material foliosa. sheet has three mounted it, all morphologically uniform, seemingly belonging population. Unfortunately, none them mature fruits, would necessary identify those rank. In absence any other extant (specimens illustrations; Art. 9.4 ICN) material, designate here this lectotype accordance 9.3 9.12 ICN. Based careful study lectotype, narrow down possibilities following species: fassettii Schotsman Acta Bot. Neerl. 15: 477–483. 1966), stenoptera Novon 19: 367–369. 2009). it impossible further, fruits lectotype. considering geographical (i.e., shores Champlain), less likely could belong fassettii, only recorded more western states, namely California, Oregon Nebraska (Lansdown, l.c. 2009: 365–366; FNA Ed. Comm., Fl. N. Amer. Mexico 17: 49–54. 2019). two stenoptera) occur area nearby areas. Our taxonomic analysis shows, therefore, possibly applied listed above. insufficient unequivocal at rank, epitypified (see 9.9 ICN). Such typification conflict its thus need accepted. way, become correct currently predates both names. substituting current usage obscure undesirable evidently disadvantageous nomenclatural stability. used literature than protologue (Rafinesque, subsequent mention Repos. 3, 408. 1811). By contrast, identities accepted 364–369; Thus, objective preventing change stability, 56 ICN, proposed rejection. will most remain ascertain consider appropriate rejected arbitrarily propose epitypification identifiable earlier hermaphroditica. Acceptance allow continue these species, without threat arbitrary application Rejection mean eventually replace either GH, https://orcid.org/0000-0003-4365-6934 RVL, https://orcid.org/0000-0003-0984-4552 We grateful Cécile Aupic (Muséum National d'Histoire Naturelle) her help access specimens, John McNeill (Royal Botanic Garden, Edinburgh) improving proposal.