Senecio eriopus Willkomm (1865: 116)

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

5. Senecio eriopus Willkomm (1865: 116) . TYPE: Spain, Málaga , Sierra Bermeja, [36º29'N 05º12'W], 1845, H.M. Willkomm 729 (lectotype, designated here, COI-37583!; isolectotypes, MA-130578!, MO!, P-3688109 image!).

Senecio doronicum var. hosmariensis Ball (1873: 367) [“hosmariense”]. Senecio eriopus var. hosmariensis (Ball) Pau (1929: 90) . Senecio eriopus subsp. hosmariensis (Ball) Blanca (1996: 309) . TYPE: Morocco, Tetuán, Monte Beni Hosmar, [35º28'N 05º21'W], 12 Apr 1871, J. Ball s.n. (lectotype, designated here, K-311469!).

Senecio eriopus f. oblongifolius Vicioso , nom. nud., in sched. ( McNeill et al. 2012, ICN Art. 38.1) (MA-130577!).

Perennial herb. Rhizome 1.2–3.2 cm long, 0.5–0.8 cm in diam., ± horizontal, with swelled fastigiate roots. Stem 9–75 cm, erect, scarcely leaved, corrugated, solid, not ramificated, lanate to covered with scattered arachnoid trichomes, base without remnants of old leaves or tufts of hairs. Basal leaves 2.6–11.6 cm long, 1.8–8.2 cm wide, persistent, ovate to elliptic, sometimes lanceolate (ratio basal leaf width / basal leaf length = 0.44–1.12), obtuse, subcordate to attenuate, with a petiole 1.4–18 cm long, crenate to dentate (teeth 0.6–1.5 mm deep), arachnoid to glabrescent above, sparsely floccose to covered with scattered arachnoid trichomes beneath, sometimes violet coloured, sometimes ± discolorous. Cauline leaves 2–8; middle cauline leaves 2.3–8.8 cm long, 0.5–4.8 cm wide, alternate, lanceolate to narrowly ovate (ratio middle leaf width / middle leaf length = 0.17–0.80), acute to obtuse, sessile or attenuated into a petiole up to 8 cm long, slightly dentate, rarely subentire (teeth 0.7–2 mm deep), arachnoid to glabrescent above, sparsely floccose to covered with scattered arachnoid trichomes beneath, tertiary venation inconspicuous; upper cauline leaves 1–10 cm long, 0.1–3.5 cm wide, linear to oblong (ratio upper leaf width / upper leaf length = 0.07–0.35), acute, sessile, entire, rarely slightly dentate (teeth 1–1.3 mm deep), ± arachnoid. Synflorescence reduced to a solitary capitulum or pseudocorymbose, 5–42 cm long, with scarce linear-oblong bracts. Capitula 1–2(–3), 27.6–52.6 mm in diam.; involucre 13.2–32.8 mm in diam., 10–19 mm long, cupuliform; involucral bracts (20–)22–32(–34), 8.7–14.6 mm long, 1.1–3.1 mm wide, with scarious margin 0.2–0.8 mm wide, lanceolate to oblong, attenuate, smooth, apex slightly violet coloured with a black spot at the summit, lanate to ± arachnoid; supplementary bracts (9–)14–18(–20), 4.8–12.1 mm long, 0.5–1.7 mm wide, subulate, without scarious margin, a half to as long as involucral bracts, lanate to ± arachnoid, not imbricated. Ligulate florets 13–27, 10.9–28.2 mm long, yellow; tubular florets 5.8–9.4 mm long, 0.9–1.8 mm in diam., yellow. Achenes 3.3–7 mm long, 0.7–1.5 mm wide, subcylindrical (ratio achene width / achene length = 0.14–0.27), shorter than pappus (ratio achene length / pappus length = 0.62–0.95), with 9–11 ribs, glabrous or nearly so (scattered intercostal trichomes ca. 0.1 mm long); pappus 4.6–9.7 mm long, whitish. Chromosome number: unknown.

Iconography: — Caballero (1948: 541, 569, fig. 10).

Distribution and habitat: —S Spain and N Morocco; shrublands with Chamaerops humilis Linnaeus (1753: 1187) , Pistacia lentiscus Linnaeus (1753: 1026) , Quercus coccifera Linnaeus (1753: 995) , open woods of Pinus halepensis , Quercus ilex Linnaeus (1753: 995) , Quercus faginea , on calcareous soils; elevations of 300–1450 m ( Figure 9 ).

Phenology: —Flowering from March to June.

Etymology: —The specific epithet refers to the dense whitish colour of the indumentum on the stem and involucre.

Discussion: —The involucre lanate to ± arachnoid, with supplementary bracts a half to as long as involucral bracts, and the basal leaves ± discolorous are the distinctive characters in S. eriopus . However, it is a variable species regarding the size, abundance of indumentum, and the shape of basal leaves. On this basis, the populations from W Rif have been treated as a different subspecies ( Pau 1929, Blanca 1996). Certainly, these specimens are usually smaller, with less indumentum, and they show truncate or subcordate basal leaves. The variability within the Iberian populations is wider and embraces those found in W Rif, finding lanate specimens in Sierra de Líjar (Cádiz) and almost glabrous in Cerro Calamorro (Sierra de Mijas, Málaga). The size and the shape of basal leaves are also highly variable. Therefore, in the present taxonomic treatment we include all populations within the same taxonomic entity.

Senecio eriopus could be misidentified with S. scopolii because of the lanate involucre in some specimens, but they can be easily differentiated by the basal leaves (ovate to broadly lanceolate, usually rounded to subcordate, ± discolorous in S. eriopus vs. lanceolate to oblanceolate, rarely obovate, usually attenuate, ± concolorous in S. scopolii ). In fact, Boissier (1840: 334) recorded S. doronicum var. lanatus Koch (1837: 391) (a synonym of S. scopolii ) in southern Spain. This record has been identified as S. eriopus (G!, K!, LE!, P image!).

SYSTEMATICS OF SENECIO SECTION CROCISERIS

Phytotaxa 211 (1) © 2015 Magnolia Press • 29 Selected specimens examined. MOROCCO. Tanger-Tétouan: Jbel Dersa, parte alta, 35º36’N, 5º24’W, 10 Apr 2009, J . Calvo & I . Espejo 3492 ( MA); montis Dj. Dersa, supra Tetauen , 35º35’N, 5º23’W, 20 May 1930, P . Font i Quer 679 ( BC, MA, S); Djebel Dersa en las cumbres, 35º35’N, 5º23’W, 13 Apr 1929, J. Mas Guindal s.n. ( MA). SPAIN. Cádiz: Zahara, sierra Margarita , 36º48’N, 5º27’W, 20 June 1983, A . Aparicio & S . Silvestre s.n. ( MA); Algodonales , ladera norte de la sierra de Líjar, 36º54’N, 5º24’W, 17 May 2009, J . Calvo 3607 ( MA). Granada: Pitres, Sierra de Mecina , pico, 36º54’N, 3º19’W, 10 June 1980, J . Molero s.n. ( MA). Málaga: in montibus propé Estepona et Ronda , 36º31’N, 5º8’W, E . Boissier s.n. ( G, K, LE); Benalmádena, cerro Calamorro , 36º37’N, 4º33’W, 14 May 2009, J . Calvo 3547 ( MA); Alhaurín el Grande, Pecho Redondo , 36º37’N, 4º40’W, 15 May 2009, J . Calvo 3565 ( MA); Sierra de Mijas supr. Churiana , 36º36’N, 4º35’W, 7 May 1879, R . Huter, P . Porta & G . Rigo 1054 ( FI, K, LE, NY) .

Figures

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