Senecio eubaeus Boissier & Heldreich

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

17. Senecio eubaeus Boissier & Heldreich in Boissier (1856: 36). TYPE: Greece, Euboea , montis Xirovouni (i.e. cacuminis merid. m. Delphi), [38º37'N 23º50'E], 18 Aug 1848, T. Heldreich 2072 (lectotype, designated here, G-150322 image!; isolectotypes, BM-1025980 image!, BM-1025979 image!, C!, G-96298!, GOET-2039 image!, H-1440338!, L-794088!, L-794090!, LE!, WAG-4106 image!).

Perennial herb. Rhizome 2.5 cm long, 0.5–1.1 cm in diam., ± horizontal, with swelled fastigiate roots. Stem 27–68 cm, erect, leaved, corrugated, solid, not ramificated, floccose, base with remnants of old leaves or tufts of hairs. Basal leaves 9.5–10.6 cm long, 1.9–3 cm wide, withering early, lanceolate to oblanceolate (ratio basal leaf width / basal leaf length = 0.20–0.28), obtuse, cuneate, with a petiole 7.5–10.5 cm long, entire to slightly denticulate (denticles ca. 0.3 mm long), arachnoid (not persistent), concolorous. Cauline leaves 7–15; middle cauline leaves 5.8–12 cm long, 1.2–2.9 cm wide, alternate, widely lanceolate (ratio middle leaf width / middle leaf length = 0.14–0.32), acute to obtuse, usually sessile to semi-amplexicaul, sometimes attenuated into a petiole up to 2.2 cm long, entire to slightly denticulate (denticles 0.2–1.2 mm long), arachnoid to floccose (not persistent), tertiary venation inconspicuous; upper cauline leaves 2.5–6.5 cm long, 0.7–2.3 cm wide, lanceolate to ovate (ratio upper leaf width / upper leaf length = 0.21–0.44), acute, sessile to semi-amplexicaul, entire to slightly denticulate (denticles ca. 0.3 mm long), floccose. Synflorescence 6.5–14 cm long, corymbose, with ovate-lanceolate bracts similar to upper leaves. Capitula (2–)3–6(–7), 32.7–42.3 mm in diam.; involucre 15.8–27 mm in diam., 13–21 mm long, cupuliform; involucral bracts (18–)19–22(–27), 9.9–15.3 mm long, 1.8–2.9 mm wide, with scarious margin 0.5–0.9 mm wide, ensiform, attenuate, 0–2-keeled, apex without a black spot, lanate to floccose; supplementary bracts (10–)12–14(–15), 6.7–10.4 mm long, 0.8–2.1 mm wide, subulate, without scarious margin, a half to three quarters as long as involucral bracts, lanate to floccose, not imbricated. Ligulate florets 11–22, 16.8–24.3 mm long, yellow; tubular florets 7.5–12.3 mm long, 0.8–1.6 mm in diam., yellow. Achenes 6.4–7.5 mm long, 0.9–1.5 mm wide, subcylindrical (ratio achene width / achene length = 0.12–0.23), shorter than pappus (ratio achene length / pappus length = 0.58–0.94), with 11–17 ribs, glabrous or with scattered, intercostal trichomes 0.1–0.2 mm long; pappus 7.6–11.3 mm long, whitish. Chromosome number: unknown. Figure 24 .

Distribution and habitat: — Greece, endemic of Euboea; rocky slopes, open formations of Abies cephalonica Loudon (1838: 2325) , on calcareous soils; elevations of 600–1550 m ( Figure 19 ).

Phenology: — Flowering from June to August.

Etymology: — The epithet eubaeus refers to the Euboea island.

SYSTEMATICS OF SENECIO SECTION CROCISERIS

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Discussion: — Senecio eubaeus could be recognized by its lanate large capitula arranged in lax corymb or reduced to a solitary capitulum, and because its synflorescence bracts are foliose. This species is apparently

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CALVO ET AL.

endemic of the mountains of Euboea island, Greece. It has some morphological affinities with S. tauricola from Turkey, but S. eubaeus differs in its larger capitula and foliose synflorescence bracts.

Selected specimens examined. GREECE. Central Greece: Euboea, Kandilion gebergte, ten zuiden van Troupion, 38º41’N, 23º26’E, 24 June 1969, A . Fokkinga s.n. ( L); Insula Euboea, montis Delphi , 38º37’N, 23º50’E, July 1901, C . Leonis 4344 ( B, E, FI, G, H, LE, M, O, WU); Euboea, in monte Candyli , 38º41’N, 23º27’E, 26 July 1871, T . G . Orphanides s.n. ( K); in insula Euboea, in monte Kandyli , 38º41’N, 23º27’E, 7 Aug 1871, T . G . Orphanides s.n. ( WU); in monte Xirovuni Eubaea supra Steni , 38º36’N, 23º50’E, 30 July 1871, T . G . Orphanides s.n. ( FI, WU); in insula Euboea, mt. Candyli , 38º41’N, 23º27’E, 7 Aug 1886, T . G . Orphanides s.n. ( G, S, UPS, WU); Euboea, montis Dirphys, 38º37’N, 23º50’E, 11 July 1965, D. Phitos 3955 ( M); insula Euboea septentrionalis: montes Kandili , 38º41’N, 23º27’E, 30 May 1955, K . H . Rechinger 16732 ( G, M) .

Figures

FIGURE 19. Distribution map for Senecio macedonicus Grisebach subsp. macedonicus (▲), S. macedonicus subsp. barckhausiifolius (Boissier & Heldreich) Calvo (∆), and S. eubaeus Boissier & Heldreich (●).

FIGURE 24. A–I. Senecio eubaeus Boissier & Heldreich—a. Habit (drawn from Leonis 4344, E).—b. Habit (drawn from Fokkinga s.n. 24 June 1969, L).—c. Capitulum (drawn from Leonis 4344, E).—d. Involucral bract (drawn from Leonis 4344, E).—e. Supplementary bract (drawn from Leonis 4344, E).—f. Ligulate floret (drawn from Leonis 4344, E).—g. Tubular floret (drawn from Leonis 4344, E).—h. Achene (drawn from Heldreich 2072, L).—i. Indumentum of achene (drawn from Heldreich 2072, L). J–K. Senecio tauricola Matthews (drawn from Bisby 92, E).—j. Synflorescence.—k. Involucral bract.—l. Supplementary bract.