Centaurea ravansarensis Ranjbar & Negaresh (2013: 432)

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

27. Centaurea ravansarensis Ranjbar & Negaresh (2013: 432) . Type:— IRAN. Prov. Kermanshah: 5 km from Ravansar, Bave Geh village , Shahu mountains , 1418 m, 31 June 2012, Ranjbar & Negaresh 28801 (holotype BASU!, isotypes BASU!, photo herb. Negaresh). ( Fig. 57 )

Biennial plants, with thick fleshy taproot, whole plant usually grayish-green, 55–80 cm tall; collar of fibrous petiolar remains present at stem base. Stem erect, almost simple, ca. 7 mm in diam. at base, cylindrical, pale green, with thinly white striations, sparsely leafy throughout, lower part subglabrous or with sparse hirsute-articulate hairs, median part loosely covered with hirsute-articulate hairs, up to 1.5 mm long, upper part loosely covered with arachnoid and sessile glandular hairs. Leaves rigid, papyraceous (on drying), almost densely covered with short hirsute-articulate hairs, up to 0.5 mm long, especially along midrib and veins, and sessile glandular hairs. Basal leaves withered at anthesis, petiolate, broadly ovate, 24–26 × 12–13 cm, cartilaginously denticulate, truncate at base, acute at apex. Lower cauline leaves simple, usually withered at anthesis, lanceolate or broadly lanceolate or subcordate-ovate, 22.5–30 × 8–11 cm, sometimes cuneate at base, with a petiole 8–14 cm long, denticulate or entire, acute at apex. Median cauline leaves sessile, lanceolate or lanceolate-elliptic or subpandurate, 12–19 × 3–6 cm, broadly decurrent, up to 50 mm along stem, denticulate, sometimes entire, acuminate at apex. Upper cauline leaves increasingly smaller, sessile, simple, lanceolate, 4.5–7 × 1–3 cm, loosely covered with arachnoid and sessile glandular hairs, decurrent, up to 15 mm along stem, acuminate at apex. Capitula few, 3 to 5, arranged in a raceme, upper peduncles 2.5–6.5 cm long, sometimes with bracts similar to phyllaries with small stramineous and chaffy appendages. Involucres ovoid-globose, sometimes ovoid-subcupuliform, truncate at base, 35–43 × 35–40 mm. Phyllaries multiseriate, yellow-greenish in sicco, imbricate, coriaceous-scarious, with loosely floccose-tomentose hairs. Appendages medium-sized, concealing a major part of phyllaries, chartaceous, not decurrent; cilia numerous, 7–12 on each side, 1–4 mm long; spines narrowly triangular, (3–) 5–9 mm long, longer than nearest cilia. Outer phyllaries oblong, 3–4 × 6–9 mm; appendages ovate, 11–13 × ca. 10–11 mm (including cilia and spine), straw-coloured. Median phyllaries broadly oblong, 10–15 × 9.2–10.5 mm; appendages ovate-triangular or triangular, 15–17 × 11–13 mm (including cilia and spine), straw-coloured to pale brown. Inner phyllaries lanceolate-oblong or lanceolate, 20–32 × 9–11 mm; appendages narrowly triangular, 11–16 × 4–10 mm (including cilia and spine), deep brown to blackish. Flowers purple; central florets hermaphroditic, 45–50 mm long, corolla ca. 17 mm long, 5-lobed, lobes 7.5–9 mm long, with orange nerves; peripheral florets sterile, equal to central ones, numerous (15–20 in each capitulum) and conspicuous, finely dissected, not radiant, 3–4-lobed, limb lobes linear, ca. 8 mm long. Achenes oblong, ca. 7 mm long, 3.8–4 mm wide, smooth and shiny, yellowish, rounded at apex, sparsely covered with hairs; insertion areole lateral, ca. 0.8 mm long, hairy. Pappus persistent, multiseriate, scabrous, pale brown, ca. 11.5–12 mm long, bristles of inner rows very slightly longer than others.

Taxonomic and distribution remarks: — Centaurea ravansarensis is a narrow endemic to Kermanshah Province, W Iran (Ranjbar et al. 2013) ( Fig. 55 ). It is an Irano-Turanian element, and grows on fallow fields and along roadsides, at elevations of 1350–1450 m ( Figs. 57B ). Centaurea ravansarensis is only found in Shahu Mountains, along Ravansar- Kamyaran road. It is similar to C. regia var. regia in its texture of leaves, decurrent upper cauline leaves, texture of appendages and size of achenes. However, it differs from C. regia var. regia by its stem in the lower part subglabrous or with sparse hirsute-articulate hairs, median part with loose hirsute-articulate hairs, up to 1.5 mm long, upper part loosely arachnoid and with sessile glandular hairs (vs. arachnoid-tomentose, finally glabrous, sometimes the lower part with hirsute-articulate hairs), upper peduncles 2.5–6.5 cm (vs. 10–15 cm) long, involucres ovoid-globose, sometimes ovoid-subcupuliform, 35–43 × 35–40 mm (vs. subglobose, 40–55 × 40–60 mm), phyllaries loosely floccose-tomentose (vs. glabrous), appendages medium-sized, concealing a major part of phyllaries (vs. large, totally concealing phyllaries), median appendages ovate-triangular or triangular, 15–17 × 11–13 mm (including cilia and spine), straw-coloured to pale brown (vs. broadly ovate, 20–25 × 20–25 mm (including cilia and spine), white, sometimes straw-coloured), inner appendages narrowly triangular, deep brown to blackish (vs. ovate, white, sometimes straw-coloured), cilia 7–12 on each side, 1–4 mm long (vs. 10–17 on each side, (3–) 4 –6 mm long), spine of median appendages (3–) 5–9 mm (vs. (8–) 9–14 mm) long, insertion areole hairy (vs. glabrous), and also in the pappus: bristles of inner rows very slightly longer than others (vs. bristles of inner rows much shorter than others, 2–5 mm long).

Chromosome numbers: —Unknown.

Selected specimens examined:— IRAN. Prov. Kermanshah: Ravansar toward Kamyaran, 1–3 km after Ravansar , 1375 m, 29 May 2014, Negaresh & Kamalnejad 20136 ( HUI!); Negaresh & Kamalnejad 148 (herb. Negaresh!); Negaresh & Kamalnejad 149 (herb. Negaresh!) .

Figures

FIGURE 55. Distribution of Centaurea phlomoides (circles), C. rahiminejadii (squares), and C. ravansarensis (triangles).

FIGURE 57. Centaurea ravansarensis Ranjbar & Negaresh (Ranjbar & Negaresh 28801, BASU). A. close up of capitule. B. habit. C. median cauline leaves (shape and indumentum). Scale A–C = 2 cm.