Thymus pulegioides L. (sect. Serpyllum (Miller) Benth.; Lamiaceae) is a highly polymorphic and widespread species distributed across to temperate parts of Europe (Jalas & Kaleva, 1970; Jalas, 1972, 1974; Ložiene, 2006; Morales, 2010).

As part of taxonomic and nomenclatural studies of the genus Thymus L. for the Valencian flora (see Ferrer-Gallego et al., 2013, 2019; Pedauyé et al., 2016; Ferrer-Gallego, 2019), the original material and typification of the name Thymus pulegioides has been studied. The nomenclatural type of T. pulegioides has been recently discussed by Nachychko & Sosnovsky (2020). However, a new interpretation of the Linnaeus original material should be made for effective typification of the name.

Linnaeus (1753: 592) described Thymus pulegioides providing a short diagnosis “THYMUS ramis verticillatis longis, foliis ovalibus striatis”, followed by the synonym “Acinos thymi folio & facie, floribus inexpansis” cited from Morison (1699: 404, s. 11, t. 19, f. 6). The protologue also includes “Habitat Monspelii. D. Sauvages”, and a description “Habitus Melissae pulegioidis f. Mentha pulegii, at Cacyces bilabiati a Satureja, ore barbati a Melissa & Mentha eam distinguunt. Caulis spithamens, erectus. Rami pauci, simplices, breves. Folia ovalia, obtuse, glabra, subtus striata. Rami & plantae maxima pars verticillis obvallata”. The reference quoted by Linnaeus (Morison, 1699) includes an illustration that can be considered as original material.

Several authors (e.g. Ronniger, 1924, 1944; Klokov, 1954; Menitsky, 1978, Mártonfi, 1997; Jarvis 2007; Nachychko & Sosnovsky, 2020) mentioned that there are at least two specimens at LINN (Herb. Linnaeus Nos. 38.5 and 38.6) that can be treated as Linnaeus’ original material of T. pulegioides. The sheet No. 38.5 LINN bears a stem, with leaves and flowers, and is annotated “Monsp.” [Monspeliensis] and “8” (the number in the Species Plantarum for Thymus pulegioides) by Linnaeus, and “thymoides / Thymus pulegioides Sp. Pl. 1. No. 8” by James Edward Smith (image available at http://linnean-online.org/153). On the other hand, the sheet No. 38.6 LINN bears a stem, with leaves and flowers, and is annotated “Satureja”, “thymoides”, and “8” by Linnaeus (image available at http://linnean-online.org/154).

According to Jarvis (2007), the “lectotype” was “effectively” designated by Ronniger (1944: 37) from the specimen Herb. Linnaeus No. 38.5 (LINN), and this viewpoint was subsequently adopted by modern monographers of Thymus (e.g. Morales, 2010; Bartolucci et al., 2013; Knyasev, 2015; Nachychko et al., 2019). However, recently Nachychko & Sosnovsky (2020) conclude that the publication of Ronniger (1944) is not the place of effective designation of the lectotype of T. pulegioides. Ronniger (1944) used the following phrase: “Die Originalpflanze liegt im Herbar Linné heute noch aufbewahrt” [The original plant is still preserved today in the Linnaean Herbarium]. In this sense, according to Nachychko & Sosnovsky (2020), the Ronniger’s (1944) term “Originalpflanze” meant “original specimen” and was not intended as an equivalent of the term “type” (typus). Therefore, according to Art. 7.11 of the Shenzhen Code (see Turland et al., 2018) in its strict interpretation (see, e.g. Ex. 12), an equivalent of the term “type” must be one of its “linguistic equivalents” (in German: “Typus” or “Typ”), none of which was used by Ronniger (1944) (see Nachychko & Sosnovsky, 2020).

On the other hand, Mártonfi (1997: 158), and later Nachychko & Sosnovsky (2020: 25), treated the specimen Herb. Linnaeus No. 38.6 (LINN) as “lectotype” of T. pulegioides. However, Linnaeus explicitly cited a gathering in the protologue, with a specific locality and author, as “Habitat in Monspelii. D. Sauvages” (see Shenzhen Code Art. 40 Note 1 and Note 2), identifiable as a specific specimen currently preserved at LINN herbarium (No. 38.5 LINN). Therefore, unfortunately, the “typification” of Mártonfi (1997), supported by Nachychko & Sosnovsky (2020), is ineffective according to Art. 9.12 of the ICN (Turland et al., 2018).

According to Jarvis (2007: 226), Sauvages[1] gave his herbarium of plants from southern France to Linnaeus in 1749. Although not all of the plants carry Sauvage’s labels, it seems clear that in many cases [see e.g. No. 290.12 (LINN) as the lectotype of Illecebrum cymosum L.; No. 741.4 (LINN) as the lectotype of Moluccella frutescens L.; No. 655.19 (LINN) as the lectotype of Potentilla hirta L.], where he is mentioned in the protologue, corresponding material in LINN carries “Monsp.” and in all likelihood came from him.

In conclusion, because Sauvages’s material at LINN (now No. 38.5) has been cited in the protologue by Linnaeus, and both (protologue and specimen) are linked, it is a syntype (according to Shenzhen Code Art. 9.6) and has precedence in lectotype designation over unmentioned specimens and cited illustrations according to Art. 9.12 of the ICN. It is therefore the obligate lectotype and accordingly designated here as such.

Fortunately, this specimen clearly represents the traditional concept and current application of the name Thymus pulegioides (e.g. Jalas & Kaleva, 1970; Jalas, 1972, 1974; Ložiene, 2006; Morales, 2010).

Thymus pulegioides L., Sp. Pl.: 592. 1753.

Ind. loc.: “Habitat Monspelii.”

Lectotype (designated here): “Monsp.” [Monspeliensis] (Montpellier, France), François Boissier de la Croix de Sauvage s.n., s.d., Herb. Linnaeus No. 38.5 (LINN [photo!]) (image available at http://linnean-online.org/153).