Systematic Botany (2015), 40(3): pp. 900–913 © Copyright 2015 by the American Society of Plant Taxonomists DOI 10.1600/036364415X689320 Date of publication September 22, 2015 A Taxonomic Revision of the Eurasian/Northwestern African Senecio doria Group (Compositae) Joel Calvo1,2 and Carlos Aedo1 1Real Jardín Botánico-CSIC, Plaza Murillo 2, 28014 Madrid, Spain. 2Author for correspondence ([email protected]) Communicating Editor: Chuck Bell Abstract—The taxonomic complexity of the Senecio doria group (Compositae, Senecioneae) is reflected in the heterogeneous treatments that have been proposed and the poor knowledge of some species. This species group consists of perennial herbs distributed in Europe, western and central Asia, and northwestern Africa. The first worldwide revision of this group recognizing seven species is presented here (i.e. S. altissimus, S. bithynicus, S. doria, S. fontanicola, S. legionensis, S. morisii,andS. umbrosus). In this new taxonomic treatment S. legionensis and S. fontanicola are recognized at the specific rank. On the other hand, S. macrophyllus from eastern Europe/western Asia has been synonymized to S. doria. Senecio bithynicus and S. morisii are described as new species. Eleven names are lectotypified. Descriptions, distribution maps, and an identification key are provided for all the species included. Keywords—Asteraceae, lectotypification, new species, Senecio section Doria, taxonomy. The Senecio doria group (Compositae, Senecioneae) is a uted throughout northwestern Africa (Morocco), Europe taxonomically complex assembly of taxa centered around (lacking in the north), and western Asia (Caucasus, north- S. doria L. This group belongs to S. sect. Doria (Fabr.) Godr., western Turkey, and Aralo-Caspian region), growing from sea which comprises between 14 and 24 taxa according to the level to 2,300 m. Over time, many classifications have been available regional works (Roldugin 1966; Matthews 1975; proposed for this group, although a comprehensive taxo- Wiebe 1997; Greuter 2008; Yilin et al. 2011). Along with S. sect. nomic revision was hitherto still needed. Senecio, S. sect. Crociseris (Rchb.) Boiss., and S. sect. Jacobaea The concept of the S. doria group was indirectly established (Mill.) Gray, section Doria is one of the four main sections of by Chater and Walters (1976), who treated all related taxa to western Eurasian/northern African Senecio species that are S. doria as subspecies (i.e. subsp. doria, subsp. kirghisicus (DC.) classically recognized (Willkomm 1865; Boissier 1875; Chater, subsp. legionensis (Lange) Chater, and subsp. umbrosus Wissjulina 1962; Chater and Walters 1976; Konechnaya 1994; (Waldst. & Kit.) Soó). Before them, Schischkin (1961) and most Menitsky and Konechnaya 2008). Recent phylogenetic studies of the central European authors who worked on this group carried out by Pelser et al. (2007) and Calvo et al. (2013) (Reichenbach 1853; Nyman 1879; Hegi 1928) recognized suggest that species of S. sect. Doria and S. sect. Crociseris most taxa of the group as different species. Concerning the (Rchb.) Boiss. form a clade, and therefore that both sections placement of S. kirghisicus DC. within S. doria as proposed should be synonymized. However, only four sect. Doria spe- by Chater and Walters (1976), recent studies (Calvo et al. cies were included in the analyses. To firmly establish the 2011, 2014a, 2015) suggest that it shares close morphological phylogenetic relationships between both sections a molecular similarities with S. racemosus, and therefore, it is best placed study including all the sect. Doria species is required. To this in S. sect. Crociseris. aim, the limits and the species composition of S. sect. Doria In the geographic frame of the Iberian Peninsula, Pérez have to be further studied. Morales et al. (1989) followed a narrow concept of S. doria The widespread S. nemorensis L. and its allied taxa is another s. s. and they differentiated four taxa: S. doria, S. laderoi Pérez controversial group within section Doria. It is distributed Morales, M. E. García & Penas subsp. laderoi, S. laderoi subsp. from western Europe to central Asia and northeastern Asia cantabricus Pérez Morales, M. E. García & Penas, and (i.e. Mongolia, China, and Japan according to Yilin et al. S. legionensis Lange. Likewise, Grulich and Hodálová (1994) 2011), and it includes highly variable taxa with numerous carried out a taxonomic revision of the group in central and populations displaying intermediate forms (Hodálová 1999; southeastern Europe. It represents the only recent revision of Oberprieler et al. 2010). Senecio sarracenicus L. (= S. fluviatilis the group in that region. The authors recognized S. doria, Wallr.) is another species belonging to section Doria that has S. macrophyllus M. Bieb., S. umbrosus Waldst. & Kit., and they a wide distribution (Europe, eastern Anatolia, central Asia, described S. fontanicola Grulich & Hodálová as a new species. central Siberia) and it should be thoroughly revised along its More recently, Greuter (2008) accepted only four species in whole range. A poorly known species, S. racemulifer Pavlov., the circum-Mediterranean countries: S. doria, S. legionensis, occurs in the Tashkent Region (Uzbekistan). The architecture S. macrophyllus,andS. umbrosus.However,theauthornoticed of the involucres and the number of ligulate florets (8–10) the uncertain taxonomic position of some taxa (S. fontanicola, lead us to tentatively consider it a member of S. sect. Doria. S. doria subsp. laderoi (Pérez Morales, M. E. García & Penas) These are some examples that highlight the need to revise Blanca), and he tentatively included them within S. doria.Chater the taxonomy of the remaining sect. Doria species to clarify and Walters (1976) also underlined the doubtful status of some the relationships between sect. Doria and its allied relatives. plants from Spain with tomentose-lanate indumentum. Like- The S. doria group includes rhizomatous herbs with leaves wise, the circumscription of S. doria and S. macrophyllus is not undivided and decreasing in size up the stem, involucre clear and the geographical delimitation of both species differs with supplementary bracts, and yellow radiate capitula with according to the authors (Grulich and Hodálová 1994; Greuter 5–10 ligulate florets. The achenes are subcylindrical with 2008). All these reasons highlight that S. doria group remains pappus, glabrous or with indumentum. The group is distrib- poorly known and thus it requires a thorough revision. 900 2015] CALVO AND AEDO: TAXONOMY OF SENECIO DORIA GROUP 901 The aim of the research presented here is to revise the Taxonomic Treatment S. doria group and to propose a modern and useful taxonomic The main morphological characters revealed as useful for treatment, including updated nomenclature, descriptions, dis- distinguishing between species are the number and shape of tributions maps, drawings, and an identification key. supplementary bracts, length of involucral bracts, number of lig- ulate florets, achene indumentum, and the shape of basal leaves. Senecio doria Group—Rhizomatous perennial herbs. Stem Materials and Methods 0.5–2 m, solid or fistulous, glabrescent to covered with long multicellular trichomes (sometimes slightly arachnoid), green- Around 420 dried specimens were studied from the following ish or with the lower half brick-red coloured. Basal leaves 8– herbaria: BC, CAG, FI, G, GE, HGI, LEB, LOU, MA, MT, and SAV. Only – photographs of specimens or additional information were available from 46 cm long, 1.8 18 cm wide, oblanceolate, linear-lanceolate to other institutions: BEO, BM, BP, CL, COI, KW, LE, LJS, P, PAD, PO, widely lanceolate, elliptic or ovate, obtuse to acute, attenuate PRC, SOM, and TO. to rounded (sometimes decurrent along the petiole), entire A comprehensive synonymy of the S. doria group is compiled. Types to distantly dentate, glabrous to arachnoid-floccose beneath, of all accepted names and most synonyms have been studied, although – we had difficulties while locating the type of the name S. umbrosus var. with a petiole 2 24 cm long slightly widened at the base. Cau- subtuberculatus Borbás ex Formánek. line leaves narrowly lanceolate to ovate or pandurate, sessile A general description of the whole group and a description for each to amplexicaul. Capitula 6–350, 12–24 mm diam; involucre species with the relevant characters are provided. Qualitative characters cylindrical-campanulate or subcylindrical; involucral bracts were studied directly by eye or with the aid of binocular lenses, while (10–)12–13(–16), 3.7–8.2 mm long, 0.7–2.6 mm wide, linear to the quantitative characters were recorded using a Mitutoyo digital caliper, CD-15DC. The most frequent values are given by percentiles and lanceolate, acute, glabrous to weakly arachnoid; supplemen- are shown without parentheses, and the extreme values are included in tary bracts (1–)3–5(–10), 1.2–5.1 mm long, 0.3–0.7 mm wide, parentheses. Habitat, elevation, and flowering period are compiled from linear to linear-triangular or slightly widened at the base, herbarium labels. a quarter to a half as long as involucral bracts, glabrous to The leaf length provided in the descriptions corresponds to the lamina weakly arachnoid (rarely slightly floccose). Ligulate florets length, and the number of supplementary bracts indicated is the number – – – – of bracts inserted at the base of the involucre. Those appearing on the 5 8( 10), 6 18.2 mm long. Achenes 2.9 4.5 mm long, sub- stem near the involucre are considered