Senecio buschianus Sosnowsky (1929: 84)

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

Phytotaxa 211 (1) © 2015 Magnolia Press • 73 22. Senecio buschianus Sosnowsky (1929: 84) . Jacobaea buschiana (Sosnowsky) Nordenstam & Greuter in Greuter & Raab-Straube (2006: 712). TYPE: Russia, Kabardino-Balkaria, declivio S montis Mekhtygen, in depressione Guzojlanbau-baschi-këz, [43º06'N 43º31'E], 29 Aug 1927, E. Busch & N. Busch 76 (lectotype, designated here, TBI image!).

Senecio pseudoracemosus Grossheim (1933: 60) . SYNTYPES: “In Caucaso occidentali”, C.A. Meyer s.n. (LE?, not found); Azerbajdzan, Kuba, prope p. Aput, 29 July 1930, M.F. Sachokia s.n. (TB?, not found).

Perennial herb. Rhizome unknown. Stem 16–62 cm, erect, scarcely leaved, corrugated, solid, not ramificated, ± tomentose to weakly arachnoid, base with fibrous remnants of old leaves and without tufts of hairs, sometimes violet coloured. Basal leaves 5.5–20.5 cm long, 1.6–6.2 cm wide, persistent, elliptic to oblanceolate (ratio basal leaf width / basal leaf length = 0.22–0.41), obtuse, rarely acute, attenuate to cuneate, with a petiole 2.5–14 cm long, irregularly dentate (teeth 0.8–3.7 mm deep, increasing in size towards base), ± tomentose to weakly arachnoid, sometimes glabrescent above (trichomes 0.3–1.1 mm long), concolorous. Cauline leaves 3–6; middle cauline leaves 4.2–16 cm long, 0.6–4.1 cm wide, alternate, lanceolate to oblanceolate (ratio middle leaf width / middle leaf length = 0.13–0.27), acute to obtuse, semi-amplexicaul auriculate to sessile, rarely attenuated into a petiole up to 4 cm long, dentate (teeth 0.6–3 mm deep), ± tomentose, sometimes glabrescent above (trichomes 0.6–1.2 mm long), tertiary venation usually inconspicuous; upper cauline leaves 0.9–10.5 cm long, 0.3–3 cm wide, lanceolate (ratio upper leaf width / upper leaf length = 0.16–0.36), acute, semi-amplexicaul auriculate to sessile, dentate to subentire (teeth 0.5–3 mm deep), ± tomentose to weakly arachnoid. Synflorescence 4–31 cm long, corymbose to pseudoracemose, with oblong-lanceolate bracts, often auriculate. Capitula (3–)4–7(–12), 41.2–50.8 mm in diam.; involucre 15.4–22.3 mm in diam., 11–15 mm long, obconical; involucral bracts (13–)15–20(–22), 8.7–11.7 mm long, 2.4–4.8 mm wide, with scarious margin 0.4–1.2 mm wide, lanceolate to oblong, attenuate, weakly 1–3- keeled, apex often violet coloured, tomentose to arachnoid, denser towards the base (trichomes 0.3–1 mm long); supplementary bracts (7–)8–10(–13), 4.3–7.9 mm long, 0.8–1.7 mm wide, subulate, without scarious margin, a half to three quarters as long as involucral bracts, tomentose to arachnoid, not imbricated. Ligulate florets ca. 13, 24.5–27.4 mm long, yellow; tubular florets 7.1–8.4 mm long, 1.1–1.5 mm in diam., yellow. Achenes 4.2–4.5 mm long, 1.1–1.6 mm wide, subcylindrical (ratio achene width / achene length = 0.26–0.39), shorter than pappus (ratio achene length / pappus length = ca. 0.53), with 9–11 ribs, glabrous with some trichomes near the top 0.12–0.2 mm long; pappus ca. 7.9 mm long, whitish. Chromosome number: unknown.

Iconography: — Sosnowsky (1929: 85, pl. 2).

Distribution and habitat: — Azerbaijan, Russia; subalpine meadows, rocky slopes; elevations of 1900–3650 m ( Figure 28 ).

Phenology: — Flowering from July to August.

Etymology: — Senecio buschianus is named in honor of Nikolai Adolfowitsch Busch (1869–1941), Russian botanist and explorer.

Discussion: — Senecio buschianus is a species characterized by its large capitula, synflorescence corymbose to pseudoracemose, and its involucre tomentose to arachnoid, denser towards the base and the pedicels. The base of the stem usually bears fibrous remnants of old leaves (character shared with S. racemosus ), and it is sometimes violet coloured. The similar species is S. racemosus (see comments under it).

Aside from the lectotype, we found at LE other four Busch’s specimens that have the same revision label in Sosnowsky’s handwriting showing “ Senecio buschianus m. sp. n.” [mihi, species nova]. Since the collection date of these specimens is 31 Aug 1927 instead of 29 Aug 1927, and the collection number 76 is lacking, we do not consider them as isolectotypes .

Selected specimens examined. AZERBAIJAN. Daghlig Shirvan: Gub. Baku, distr. Schemacha , in pascuis montis Dibrar , 40º50’N, 48º38’E, 25 July 1900, F. N . Alexeenko 13408 ( LE). Guba-Khachmaz: Daghestan Muruch , 41º19’N, 48º10’E, 1873, A . Becker 229 ( LE) . RUSSIA. Dagestan: distr. Dargi prope m. Schunu ( Cila ), 42º6’N, 47º14’E, 20 July 1898, F. N . Alexeenko 12533 ( LE); Agul’skiy district, near Kokhma-dag pass, alpine belt, 41º51’N, 47º36’E, 4 Aug 1940, R . Elenevsky s.n. ( LE); Daghestania australis Kurusch , 41º16’N, 47º49’E, 1872, F . Faust 48 ( LE); Akushinski district DASSR , Tanti village, 42º9’N, 47º18’E, 29 Aug 1968, Guseinov s.n. ( TBI); Agul’skiy district, near Chirag village , west slope, 41º50’N, 47º26’E, 19 Aug 1981, Y . Menitsky, T . Popova & T . Gorlina 453 ( LE) . RUSSIA. Kabardia-Balkaria: Kabkaz, p. Malka , 43º34’N, 42º34’E, 9 Aug 1906, I. J . Akinfiew s.n. ( LE); Sukan, under a mountain Mekhtigen , track Zilandilanbaulli , 43º6’N, 43º32’E, 31 Aug 1931, E . Busch & N . Busch s.n. ( LE, TBI); Sukan, m. Kisirtsi-kaia , Kisirci-kiunkium pass, 43º9’N, 43º32’E, 30 July 1931, E . Busch & N . Busch s.n. ( LE, TBI); descent to the valley of the Musht river , south subalpine meadow slope, 43º42’N ,

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CALVO ET AL.

42º40’E, 22 Aug 1939, R . Elenevsky s.n. ( LE); north side of Elbrus, upper reaches of the Malka river , ridges of side range , 43º24’N, 42º33’E, 29 July 1981, Y . Menitsky, T. Popova & T. Gorlina 430 ( LE). Karachay-Circasia: Steppe south slope of rocky range down Khasaut village , 43º42’N, 42º31’E, 20 Aug 1939, R . Elenevsky s.n. ( LE); Terskaya Governorate, near Kislovodsk, Epchik-kal , 43º43’N, 42º40’E, 15 Aug 1925, Y. C . Frolov 200 ( LE). North Ossetia – Alania: Vladikavkaz district, Kadat village, Khampaladag track, south exposure slope , 42º50’N, 44º15’E, 19 Aug 1958, N. E . Vargina s.n. (LE).

SYSTEMATICS OF SENECIO SECTION CROCISERIS

Figures

FIGURE 28. Distribution map for Senecio racemosus (Bieberstein) Candolle subsp. racemosus (▲), S. buschianus Sosnowsky (○), and S. trapezuntinus Boissier (●).