Remarks.
The name Achillea impatiens was described by Linnaeus (1753: 898) as “8. ACHILLEA foliis pinnatis: pinnis distantibus lineari-lanceolatis: basi sursum auctis”; this diagnosis was taken directly from van Royen (1740: 176); a polynomial published by Gmelin (1747: 197, t. 83, f. 1; “Achillea foliis pinnatis, pinnis longis acutis: inferioribus sursum dente auctis glaberrimis”) was also cited; the provenance was given as “Habitat in Sibiria”. In addition, a description of the plant (“Planta albis gaudet floribus. Foliorum pinnae remotae et admodum distantes, distinguunt plantam a reliquis”) was reported.
Among the elements associated with the protologue of Achillea impatiens, the illustration published by Gmelin in “Flora Sibirica” (1747: 197, tab. LXXXIII, fig. I) (see https://bibdigital.rjb.csic.es/viewer/12378/?offset=#page=357&viewer=picture&o=bookmark&n=0&q=) constitutes original material because it was explicitly cited by Linnaeus in the protologue. A specimen preserved in the Linnaean Herbarium at LINN (Herb. Linn. No. 1017.9; numbering follows Savage 1945) has been also traced. The sheet bears the Linnaean annotation “8 impatiens”, where the number “8” corresponds to the Linnaean number of A. impatiens in “Species Plantarum”. This means that LINN-1017.9 is part of the original material for the name. The specimen is well preserved and displays diagnostic features consistent with both the protologue and Gmelin’s illustration. At LINN-HS (Herb. Smith), two further specimens are preserved on sheet No. 1315.24 (Nos. 1315.24.1 and 1315.24.2; image available at https://linnean.access.preservica.com/uncategorized/IO_f317aecb-4592-4cf3-ad3a-c32031611710/). The original annotations on the sheet provide explicit evidence of their post-1753 provenance. Specimen 1 is labelled “Rev. Mr. Watts’s garden, Ashill. Sep. 1. 1801”, while specimen 2 is labelled “From his herbarium”; the sheet also bears the later annotations “Achillea impatiens” and “Mr Watts”. Thus, specimen 1 was obtained from Rev. Mr. Watts’s garden on 1 September 1801, 48 years after the publication of “Species Plantarum” (1753), while specimen 2 is explicitly identified as having come from his herbarium. The explicit post-1753 provenance of the specimens demonstrates that they were not available to Linnaeus when he prepared the protologue of A. impatiens. Accordingly these specimens cannot be considered original material for the name A. impatiens.
No specimen linked to the diagnosis cited by Linnaeus from van Royen (1740) could be located in the van Royen Herbarium (preserved at L).
All original elements identified are consistent with the protologue of Achillea impatiens. Both the specimen at LINN (No. 1017.9) and the illustration published by Gmelin (“Flora Sibirica” 2: 197, tab. LXXXIII, fig. 1) exhibit the diagnostic characters emphasized by Linnaeus, including pinnately divided leaves with elongate, acute, linear-lanceolate segments, the lowermost segments bearing an additional upward-directed tooth, and the distinctly remote arrangement of the leaf segments, leaving the rachis conspicuously exposed, a feature that Linnaeus explicitly regarded as distinguishing the species from the remaining species of the genus.
In accordance with Art. 9.12 of the ICN, the specimen Herb. Linn. No. 1017.9 (LINN) (Fig. 1) is here designated as the lectotype of Achillea impatiens. The lectotype matches the protologue and the traditional concept and current application of the name A. impatiens (e.g., Heimerl 1884; Afanasyev and Bochantsev 1961; Richardson 1976; Guo et al. 2004; Ehrendorfer and Guo 2006).
Candolle (1838: 22) accepted this species under the genus Ptarmica Mill. and published the name Ptarmica impatiens. In the protologue, he explicitly cited the name Achillea impatiens L., as well as the main synonyms associated with the Linnaean concept of this species, including Gmelin’s illustration. Consequently, Ptarmica impatiens is a nomenclatural combination based on Achillea impatiens L., i.e. Ptarmica impatiens (L.) DC. (Art. 7.3 of the ICN), although POWO (2026) erroneously treats this name as a heterotypic synonym (i.e. Ptarmica impatiens “DC.”).