Centaurea charrelii Halácsy & Dörfler

Negaresh, Kazem & Rahiminejad, Mohammad Reza, 2018, A revision of Centaurea sect. Cynaroides (Asteraceae, Cardueae-Centaureinae), Phytotaxa 363 (1), pp. 448-450 : 448-450

8. Centaurea charrelii Halácsy & Dörfler in Dörfler (1894: 6). Type :— GREECE. In Vladova prope Vodena Macedoniae, 7 September 1893, Charrel s.n. (lectotype W! designated by Wagenitz 1960: 486, isolectotype W!). ( Fig. 21 )

Biennial plants, with thick fleshy taproot, whole plant usually green in vivo, 50–70 cm tall; collar of fibrous petiolar remains present at stem base. Stem erect, branched in upper part, 5–8 mm in diam. at base, densely leafy throughout stem, cylindrical, with thick yellowish striations, ± loosely covered with arachnoid hairs. Leaves thin, papyraceous (on drying), undivided, subglabrous to loosely arachnoid and scabrous. Basal and lower cauline leaves large, simple, petiolate, oblong or oblong-lanceolate, entire, acute at apex. Median and upper cauline leaves sessile, simple, broadly winged, lanceolate to oblong, or narrowly lanceolate, 3–10 × 0.7–3.5 cm, entire, acuminate or cuspidate at apex, rarely median leaves strongly narrowed toward base, uppermost leaves surrounding the capitula. Capitula numerous, 5 to 10(–15), arranged in a corymb, sessile or subsessile. Involucres ovoid to ovoid-oblong, 25–32 × 25–32 mm. Phyllaries multiseriate, greenish-yellow, imbricate, coriaceous, glabrous. Appendages large, totally concealing phyllaries, chartaceous, not decurrent, straw-coloured, lanceolate, 3–5 mm wide at base (excluding cilia); cilia erect, numerous, 8–15 on each side, 2–4 mm long; spines rigid, short, 3–6 mm long, slightly longer than adjacent cilia. Outer phyllaries ovate, 2–3 × 2–3 mm, appendages 10–14 × 6–11 mm (including cilia and spine). Median phyllaries lanceolate, 4–11 × 5–6 mm, appendages 13–16 × 10–14 mm (including cilia and spine). Inner phyllaries narrowly lanceolate to linear, 16–18 × 2.8–4.5 mm, appendages rounded into short spine or lacerate. Flowers yellow; central florets hermaphroditic, ± 30 mm long, corolla ± 14 mm long, 5-lobed, lobes 6–7 mm long, style longer than corolla, stigma exserted part from corolla; peripheral florets sterile, slightly shorter than central ones, numerous (15–20 in each capitulum) and conspicuous, finely dissected, slightly radiant, 5-lobed, limb lobes linear, ca. 8 mm long. Achenes oblong, 4.5–6 mm long, 2–3 mm wide, dark brown or silver-bronze, smooth or with fine striations, glabrous; insertion areole lateral, yellowish or whitish, 0.5–0.8 mm long. Pappus persistent, multiseriate, scabrous, whitish, as long as or less ½ longer than achenes, 4–8 mm long.

Taxonomic and distribution remarks: — Centaurea charrelii is a rare endemic to Edhessa and Domokos, N Greece ( Fig. 22 ). It is only known from two above localities which harbour very small and severely threatened populations (not exceeding 50 individuals in total). Centaurea charrelii grows on rocky slopes, clayey slopes, green hills, serpentine or a mixed serpentine and flysch, shrub land, scattered between Quercus cocciferas or margin of forest, and low-montane zone, at elevations of ca. 500 m. It is a Mediterranean element and is the only species of the Asiatic C. sect. Cynaroides that is found in the Mediterranean region ( Negaresh & Rahiminejad 2014), growing more than 1200 km from any other member of the same section ( Wagenitz 1975b, Constantinidis et al. 2002).

Centaurea zaferii from Turkey is the only species that shows a relationship to C. charrelii by having yellow flowers, chartaceous and lanceolate appendages (totally concealing phyllaries). Actually, the flowers and appendages are same in both species. However, C. charrelii differs from it in some characters such as stem 50–70 cm (vs. 100–150 cm) tall, basal and lower cauline leaves large, simple, oblong or oblong-lanceolate, entire (vs. very large, 60–77 × 10–15 cm, with 1–2 pairs of ± falcate or triangular lobes (4–8 cm long), denticulate), median cauline leaves 3–10 × 0.7–3.5 cm (vs. 10–15 × 3–5 cm), capitula 5 to 10(–15), arranged in a corymb (vs. capitula in 2–3 nearly congested (subsessile) at end of stem and short branches, arranged in a subraceme or racemose dichasium), involucres 25–32 × 25–32 mm (vs. 23–25 × 13–25 mm), and also appendages 3–5 mm (vs. 2–3 mm) wide at base (excluding cilia).

Chromosome numbers: — Constantinidis et al. (2002) reported the chromosome number 2 n = 4 x = 36 for Centaurea charrelii collected from Greece, Nomos Fthiotidos, Road Lamia-Domokos, Omvriaki village. This is the only count for this taxon and the first report of tetraploidy in C. sect. Cynaroides .

Selected specimens examined:— GREECE. In Vladova prope Vodena Macedoniae, 18 September 1893, Charrel

s.n. ( B!: three sheets, K!, JE!) (paratype of Centaurea charrelii ).

Figures

FIGURE 21. Centaurea charrelii Halácsy & Dörfler (Charrel s.n., B).

FIGURE 22. Distribution of Centaurea charrelii (circles), C. doddsii (squares), and C. fenzlii (triangles).