Senecio lagascanus Candolle (1838a: 357)

Calvo, Joel, Álvarez, Inés & Aedo, Carlos, 2015, Systematics of Senecio section Crociseris (Compositae, Senecioneae), Phytotaxa 211 (1), pp. 448-450 : 448-450

3. Senecio lagascanus Candolle (1838a: 357) . Senecio doronicum var. lagascanus (Candolle) Sampaio (1913: 134) . Senecio doronicum subsp. lagascanus (Candolle) Vigo (1968: 94) . TYPE: Spain, Castilla y León, montium legionensium, 1806, M. Lagasca s.n. (lectotype, designated by Bellot & Casaseca (1975: 19), G-DC!; isolectotypes, COI-37588!, MA-130656!).

Senecio ruthenensis Mazuc & Timbal-Lagrave (1854: 3) . Senecio doronicum subsp. ruthenensis (Mazuc & Timbal-Lagrave) Nyman (1879: 354) . Senecio doronicum [race] ruthenensis (Mazuc & Timbal-Lagrave) Rouy (1903: 328) . Senecio doronicum var. ruthenensis (Mazuc & Timbal-Lagrave) Bonnier (1922: 84) [“rutenensis”]. TYPE: France, Aveyron, Floyrac près Rodez, [44º22'N 2º33'E], M.H. Barrau s.n. (lectotype, designated here, P-3777686 image!).

Senecio doronicum var. minor Lagasca ex Willkomm (1865: 115) , nom. nud., pro syn. ( McNeill et al. 2012, ICN Art. 38.1).

Senecio doronicum var. floribundum Pau (1896: 59) . TYPE: Spain, Teruel , J. Benedicto s.n. (lectotype, designated here, MA-442298!).

Senecio lagascanus var. burgensis Coincy (1898: 828) . TYPE: Spain, Burgos, Cartuja de Miraflores , Fuente de la Salud, [42º20'N 3º39'W], 14 July 1897, A.H. Coincy s.n. (lectotype, designated here, P-3688136 image!; isolectotypes, P-3688134 image!, P-3688135 image!, P-3688137 image!).

Senecio doronicum subsp. lusitanicus Coutinho (1913: 641) . Senecio lagascanus subsp. lusitanicus (Coutinho) Pinto da Silva (1987: 955) . Senecio lusitanicus (Coutinho) Pérez-Romero (2009: 19) . TYPE: Portugal, Estremadura, Serra de Montejunto , pr. Buarcos, [40º11’N 8º54’W], A.X.P. Coutinho s.n. (COI?, not found).

Crociseris lusitanica Gandoger , nom. nud., in sched. ( McNeill et al. 2012, ICN Art. 38.1) (LY image!).

Jacobaea doronicum var. minor Lagasca , nom. nud., in sched. ( McNeill et al. 2012, ICN Art. 38.1) (MA-130656!).

Senecio × valdelongum Pau , nom. nud., in sched. ( McNeill et al. 2012, ICN Art. 38.1) (MA-130678!).

Perennial herb. Rhizome 1.1–3.3 cm long, 0.3–0.9 cm in diam., ± horizontal, with swelled fastigiate roots. Stem 14–108 cm, erect, leaved, corrugated, solid, not ramificated, slightly arachnoid to glabrescent, usually with ± patent long multicellular trichomes towards the lower part, base without remnants of old leaves or tufts of hairs. Basal leaves 2.8–17 cm long, 1–5.7 cm wide, persistent, lanceolate to oblanceolate, sometimes ovate (ratio basal leaf width / basal leaf length = 0.22–0.81), obtuse, rarely acute, attenuate to rounded, with a petiole 0.7–15 cm long, dentate, sometimes slightly dentate (teeth 0.4–3 mm deep), covered with scattered arachnoid trichomes to glabrescent, more dense on midrib and petiole (trichomes 0.4–2 mm long), concolorous. Cauline leaves 4–12; middle cauline leaves 0.9–16 cm long, 0.2–3 cm wide, alternate, lanceolate to oblanceolate (ratio middle leaf width / middle leaf length = 0.06–0.30), acute, sometimes obtuse, semi-amplexicaul to attenuated into a petiole up to 7 cm long, entire to slightly dentate (teeth 0.7–1.8 mm deep), covered with scattered arachnoid trichomes (trichomes 0.6–2.7 mm long) to glabrescent, tertiary venation inconspicuous; upper cauline leaves 0.5–7.6 cm long, 0.1–1.9 cm wide, oblong to lanceolate (ratio upper leaf width / upper leaf length = 0.05–0.25), acute, sessile to semi-amplexicaul auriculate, entire to slightly dentate (teeth 1.2–2.1 mm deep), covered with scattered arachnoid trichomes to glabrescent. Synflorescence 2–25 cm long, corymbose, with scarce linear-oblong bracts. Capitula (1–)2–5(–11), 24.3–46.4 mm in diam.; involucre 9–21.5 mm in diam., 7–13 mm long, cupuliform; involucral bracts (16–)21–22(–30), 6.3–12.6 mm long, 0.9–2.2 mm wide, with scarious margin 0.2–0.6 mm wide, lanceolate to oblong, attenuate, weakly 0–3-keeled, apex usually with a black spot, with scattered arachnoid trichomes (trichomes 0.3–1 mm long) to glabrescent; supplementary bracts (5–)8–10(–15), 4.3–9.8 mm long, 0.3–1.8 mm wide, subulate, without scarious margin, a half to three quarters as long as involucral bracts, with scattered arachnoid trichomes (trichomes 0.3–1.4 mm long), not imbricated. Ligulate florets 10–28, 12–23.4 mm long, yellow; tubular florets 5.3–8.9 mm long, 0.6–1.8 mm in diam., yellow. Achenes 3.8–4.9 mm long, 0.6–1.2 mm wide, subcylindrical (ratio achene width / achene length = 0.14–0.27), shorter than pappus (ratio achene length / pappus length = 0.55–0.95), with 9–12 ribs, glabrous or nearly so (some intercostal trichomes 0.1–0.2 mm long); pappus 5–8.3 mm long, whitish. Chromosome number: 2 n =40 ( Fernandes & Queirós 1971: 46, sub S. doronicum ); n =20 ( Küpfer 1972: 1753, sub S. gr. doronicum, Küpfer 1972: 1753 , sub S. ruthenensis ). Figure 8B .

Iconography: — Mazuc & Timbal-Lagrave (1854: 6, fig. 1–4, sub S. ruthenensis ); Coste (1903: 308, n.º 1843, sub S. ruthenensis ); Bonnier (1922: fig. 286, n.º 1423-2, sub S. ruthenensis ); Caballero (1948: 543, 571, fig. 11).

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CALVO ET AL.

Distribution and habitat: — Spain, France, Portugal; shrublands, meadows, woods of Quercus sp. , Pinus sp. (sometimes of Fagus sylvatica ), on calcareous or siliceous soils; elevations of 240–1650 m ( Figure 9 ).

Phenology: —Flowering from May to July.

Etymology: — Senecio lagascanus is named in honor of Mariano Lagasca y Segura (1776–1839), Spanish botanist who worked at the botanical garden of Madrid.

Discussion: — Senecio lagascanus is characterized by usually bearing several capitula with supplementary bracts shorter than involucral ones, and the lower part of the stem with a dense indumentum composed of ± patent long multicellular trichomes. Nonetheless, this taxon presents a high variability regarding the number of capitula. In the same population it is frequent to find specimens showing several capitula (up to 11) and specimens displaying a solitary capitulum.

Senecio lagascanus is similar to S. doronicum and S. provincialis , with which it partially overlaps its range, and to S. kolenatianus from northeastern Anatolia and Caucasus Mountains. This species differs from S. provincialis in the shape and number of supplementary bracts, involucre size, and the shape and indumentum of basal leaves. The supplementary bracts of S. provincialis are numerous, ± imbricated, and widened at the base, whereas S. lagascanus usually bears a lesser number of supplementary bracts that are not widened at the base. The involucre size is larger in S. provincialis , and its basal leaves are ovate to lanceolate vs. lanceolate to oblanceolate (rarely ovate) in S. lagascanus . Moreover, in S. provincialis the arachnoid indumentum beneath gives the leaves a discolorous aspect. In contrast, the S. lagascanus leaves are concolorous, covered with scattered arachnoid trichomes to being glabrescent, with the pubescence denser on the midrib and petiole. Regarding S. doronicum and S. kolenatianus , see comments under them.

The populations from Aveyron and Charente-Inférieure ( France), described as S. ruthenensis by Mazuc & Timbal-Lagrave (1854: 3), match perfectly with all diagnostic characters of S. lagascanus . Likewise, those populations from Estremadura and Beira Litoral ( Portugal) that have been described as S. doronicum subsp. lusitanicus also agree with S. lagascanus . Recently, Pérez-Romero (2009) elevated this taxon to the species rank mainly based on palynological characters. However, in the present study the morphological differences concerning useful taxonomic characters such as the number and shape of supplementary bracts or habit (size, number of cauline leaves) do not reveal sufficient differences to consider them different taxa.

There is a Gandoger’s collection of S. lagascanus from Jebel Haroun (Meknès-Tafilalet, Morocco). The collection corresponds to the Gandoger’s expedition “Flora Africae Borealis, 1910-11”. Other specimens from this expedition not present in northern Africa (i.e., Geranium sanguineum L.) suggest the probability of mislabelling. Thus, the presence of this taxon in N Africa should be confirmed by new collections.

Bellot & Casaseca (1975) lectotypified S. lagascanus with a specimen kept at G-DC., and stated that one isolectotype is kept at MA. The specimen from Candolle’ herbarium consists of only one plant that is notably ruined, without capitula and with most of the leaves broken. Fortunately the specimen kept at MA clearly shows the diagnostic characters of this species .

Selected specimens examined. FRANCE. Ariège: Pech de Caraybat près Foix, 42º57’N, 1º37’E, 15 July 1900, H . Guilhot s.n. ( NY) . Aveyron: Devèze de Floirac , près Rodez, 44º22’N, 2º33’E, 20 June 1869, J . de Puyfol 306 ( MA, WU) . Charente: Saint-Christophe, bois, 46º0’N, 0º51’E, 3 July 1898, J . Foucaud & Jousset 4265 ( G). Charente- Maritime: Courçon-d'Aunis, forêt de Benon, près de la rute de Benon, 46º13’N, 0º48’W, 10 June 1930, A . Bouchon s.n. ( B) . PORTUGAL. Beira Litoral: Quiaios, 40º12’N, 8º51’W, 25 May 1972, F . Bellot, B . Casaseca & S . Castroviejo s.n. ( MA). Estremadura: Montejunto, parte alta, alrededores Ermida de Nossa Senhora das Neves , 39º10’N, 9º3’W, 13 May 2010, J . Calvo 4623 ( MA) . SPAIN. Álava: Salvatierra, Sierra de Entzia , Atxuri, 42º48’N, 2º19’W, 6 July 1986, J. A . Alejandre & B . Fernández de Betoño 1076 ( MA) . Burgos: Castilla, Candepajares, 42º38’N, 3º1’W, 2 July 1909, H . Elías 940 ( E, H, L). Cantabria: Paracuelles, Hermandad de Campóo de Suso , 43º1’N, 4º13’W, 29 June 1986, C . Aedo s.n. ( MA) . Castellón: La Jana, rambla de Cervera, 40º28’N, 0º13’E, 28 May 2011, J . Calvo, T . Buira & D. Mesa 5550 ( MA) . Girona: Osona, Vidrà, Ciuret, alrededores de la rectoría, 42º08’N 2º19’E, 9 July 2014, J . Calvo & É . Ross-Nadié 6622 ( MA) . Huesca: Monegros, Sierra de Alcubierre , al W de San Caprasio, 41º43’N, 0º32’W, 9 June 1996, J . Molero & Ll. Sáez s.n. ( C). La Rioja: Turruncún, Sierra de Préjano, Peña Isasa , 42º10’N, 2º8’W, 25 June 1985, F . Amich & J . Sánchez 83 ( E, K) . León: Monte de Villaobispo , 42º29’N, 6º4’W, June, M . Lagasca s.n. ( MA). Navarra: Esteribar, Saigos , 42º57’N, 1º31’W, 4 June 1988, I . Aizpuru & P . Catalán 21164 ( MA) . Palencia: Cervera de Pisuerga , collados y crestas calizas entre Pico de las Cruces y Peña Celada, 42º51’N, 4º32’W, 29 May 1990, J. A . Alejandre 1075 ( MA) . Soria: Arévalo de la Sierra, in

SYSTEMATICS OF SENECIO SECTION CROCISERIS

Phytotaxa 211 (1) © 2015 Magnolia Press • 25 nemore Dehesa Mata , 41º57’N, 2º24’W, 24 June 1978, A . Segura Zubizarreta 16941 ( B, BR, C, FI, H, MA). Tarragona: Horta de Sant Joan , pr. mas de Josepó , 40º51’N, 0º18’E, 26 May 2011, J . Calvo & T . Buira 5516 ( MA). Teruel: Valacloche, 40º11’N, 1º5’W, June 1893, É . Reverchon 809 ( FI, K, NY, WU). Valladolid: Encinas de Esgueva , camino de "Fuentelasbrujas" a "El Gricio", 41º45’N, 4º5’W, 5 June 1993, R . Castillo & J. L . Fernández Alonso 10605 ( MA) .

Figures

FIGURE 8. A. Senecio provincialis (Linnaeus) Druce (drawn from Puech s.n. 27 June, M).—a1. Capitulum.—a2. Involucral bract.—a3. Supplementary bract.—a4. Ligulate floret.—a5. Tubular floret. B. Senecio lagascanus Candolle (drawn from Molero & Sáez s.n. 9 June 1996, C).—b1. Capitulum.—b2. Involucral bract.—b3. Supplementary bract.—b4. Ligulate floret.—b5. Tubular floret. C. Senecio scopolii Hoppe & Hornschuch subsp. scopolii (drawn from Pichler 65, G).—c1. Capitulum.—c2. Involucral bract.—c3. Supplementary bract.—c4. Ligulate floret.—c5. Tubular floret. D. Senecio doronicum subsp. longifolius (Willkomm) Calvo (drawn from Amich et al. s.n. 18 June 1979, MA).—d1. Capitulum.—d2. Involucral bract.—d3. Supplementary bract.—d4. Ligulate floret.—d5. Tubular floret.

FIGURE 9. Distribution map for Senecio provincialis (Linnaeus) Druce (∆), S. lagascanus Candolle (●), and S. eriopus Willkomm (▲).