The identity of Ligularia euryphylla (Asteraceae, Senecioneae)

Abstract 
 Study of the type material of Senecio euryphyllus C. Winkl. (≡ Ligularia euryphylla (C. Winkl.) Hand.-Mazz.) in the LE, K and PE herbaria revealed that each of the three sheets consists of a mixture of two different taxa: L. tongolensis (Franch.) Hand.-Mazz. and Nannoglottis carpesioides Maxim. Lectotypes for Senecio euryphyllus, S. tongolensis Franch. (≡ L. tongolensis) and S. monbeigii H. Lév. are designated. Ligularia euryphylla joins S. monbeigii as a synonym of L. tongolensis. Citation: Illarionova I. 2016: The identity of Ligularia euryphylla (Asteraceae, Senecioneae). — Willdenowia 46: 99–104. doi: http://dx.doi.org/10.3372/wi.46.46107 Version of record first published online on 25 March 2016 ahead of inclusion in April 2016 issue.


Introduction
The Eurasian genus Ligularia Cass., consisting of approximately 150 species, has its centre of species diversity in SW China. One of many species described from this region is Senecio euryphyllus C. Winkl. (1895). The name was based on specimens collected in Sichuan Province, China, by the famous Russian geographer, ethnographer and naturalist Grigory Potanin. Later H. Handel-Mazzetti (1938) made the combination for it in Ligularia, but he mentioned that he had not seen any type specimens. S. W. Liu (1989) included this species in L. sect. Corymbosae (Franch.) Hand.-Mazz. ser. Lapathifo liae S. W. Liu. This decision was based on the corymbose inflorescence and pinnately veined leaves. The species is known only from the type material, which includes three sheets: one kept in the Saint Petersburg herbarium (LE; Thiers [continuously updated]) and two duplicate sheets sent to the Kew (K) and Beijing (PE) herbaria. Study of these specimens revealed that the parts of plants present on each herbarium sheet belong to species in two different genera: L. tongolensis (Franch.) Hand.-Mazz. and Nannoglottis carpesioides Maxim.

Results and Discussion
Each of three type sheets of Senecio euryphyllus includes a sterile basal rosette with large leaves and a stem with inflorescence. The sheet in LE ( Fig. 1) has also a separate portion of the lower half of a stem with three cauline leaves. I have identified the stems with ovate-cordate leaves and corymbose inflorescence as Ligularia tongo lensis (Franch.) Hand.-Mazz. However, the plants with basal rosettes of ovate-lanceolate leaves with winged petioles and both surfaces of the leaf blade white pilose are very different. Also, the roots of these plants are not typical for Ligularia species. I suspected that these plants consisting of lower parts belonged to another genus. After examination of the LE Asteraceae collection I found specimens of Nannoglottis carpesi oides Maxim. collected by Grigory Potanin in the same locality as the specimens of S. euryphyllus: "Ta-tsien-lu, supra pagum Tshungu" and with the same collection date "16 VII 1893". Two sheets of N. carpesioides include upper halves of stems with cauline leaves and inflorescence (Fig. 3). These specimens are identical to the lower portion of the stem mounted on the type sheet of S. euryphyllus in LE. In the protologue of Senecio euryphyllus, C. Winkler (1895) gave the collection date as "16/VIII 1893". This same date we can see on the label of the sheet in LE (although the figure 15 was changed to 16). But this specimen also has a field label with the printed date "16 Iюля [July] 1893". The specimen in K (viewable via JSTOR Global Plants: http://plants.jstor.org) has the date "1893. 15/VIII " on a label. The third specimen in PE (Fig. 2) is dated "1893. 16/VII ". In the LE and K herbaria I also found specimens of Ligularia tongolensis with labels "China occidentalis, prov. Szechuan, Ta-tsien-lu, 15 Jul 1893, G. N. Potanin" and identified by C. Winkler as "Senecio tongolensis Franch." According to V. L. Komarov (1928), Grigory Potanin visited "pagum Tshzhun gu" on 15 July 1893 (in the Julian calendar, not the Gregorian calendar of modern times). I suppose that the differences in collection dates are the result of confusion on the labels. Undoubtedly these three specimens of S. euryphyllus are parts of a single gathering. Also they all have the name "Senecio euryphyllus C. Winkl." on their labels in Winkler's hand. These three specimens should be regarded as original material.
Because the original material used by the author consists of several specimens and contains parts belonging to different taxa, a lectotype should be chosen (McNeill & al. 2012: Art. 9.11 & 9.14). I designate the left-hand plant with an inflorescence on the sheet at LE (LE01013442) as the lectotype of Senecio euryphyllus. Only this stem belongs to the genus Ligularia and is thus suitable to fix the application of the name S. euryphyllus. Also this part of the material on the sheet better matches the description in the protologue than do the parts belonging to Nannoglottis carpesioides. The left-hand plant with an inflorescence on the sheet at K (K000814811) and the stem with an inflorescence in the centre of sheet (with separated leaf on right-hand) at PE (PE00030201) are the isolectotypes, the other material on those sheets being N. carpesioides. Since I consider the lectotype material of S. euryphyllus to belong to what is currently known as L. tongolensis, the names S. euryphyllus and L. euryphylla become synonyms of L. tongolensis.
The type material of Ligularia tongolensis consists of two specimens at P belonging to separate gatherings made by J. A. Soulié in Sichuan Province: Ta-tsienlou, Soulié 144 (P00723341!) and Tongolo, Soulié 137 (P00723340). Because A. Franchet (1893) cited the specimens in the protologue but did not indicate one of them as the type, they are syntypes and a lectotype can be designated. I select the specimen from Tongolo (Soulié 137) because it is in better condition, corresponds with the description and also reflects the specific epithet.
As was mentioned previously (Liu 1989;Liu & Illarionova 2011), Senecio monbeigii H. Lév. is conspecific with Ligularia tongolensis. The original material of S. monbeigii kept at E consists of two specimens belonging to a single gathering made by E. E. Maire in Sichuan Province. Since H. Léveillé (1915) cited this gathering in the protologue but did not specify a herbarium where it was conserved and did not annotate either specimen at E as the type, those two specimens are syntypes. Lauener (1976) cited the same Maire gathering as "holo. S. mon beigii, E" but without specifying which of the specimens he considered the holotype, which therefore constitutes a first-step lectotypification (McNeill & al. 2012: Art. 9.17 & 9.9). I now designate specimen E00413253, which better corresponds with the description in the protologue, as the second-step lectotype of S. monbeigii.