Centaurea sanandajensis Ranjbar & Negaresh 2013, sp. nov.

Centaurea sanandajensis Ranjbar & Negaresh, sp. nov. Figs. 1, 2.

Centaureae longipedunculatae affinis, a qua foliis basalibus 28–30 cm (nec 40–50 cm) longis, lyratis (nec lyratis vel pinnatisectis), segmentis lateralibus ab utroque latere in numero 2–3 (nec (3–)4–7(–8)), involucris ovoideis (nec oblongis) 15–16 mm (nec 22–25 mm) longis, appendicibus parvis (nec magnis), ungues phyllorum pro parte minore (nec majore) obtegentibus, semilunaribus vel breviter triangularibus (nec triangularibus), non decurrentibus (nec decurrentibus), inermibus (nec spinis 5–8 mm longis), ciliis 0.3–2 mm (nec 3–6 mm) longis, floribus 21–22 mm (nec ± 30 mm) longis differt.

Type:— IRAN. Prov. Kurdestan: Sanandaj to Marivan, 20 km to Sarv Abad, Langeriz village, 1350 m, 20 July 2012, Ranjbar & Negaresh 31630 (holotype BASU!, photo B).

Perennial plants with thickened rootstock, ca. 70 cm tall, usually completely light green, entirely glabrous; remains of stems and leaf bases of the previous year present. Stems ca. 4 to 5, erect, striate, yellowish, ca. 3–4 mm in diameter at the base, almost branched in upper part with 2 to 5 capitula. Leaves glabrous, planecoriaceous, sometimes margins subscabrous. Basal leaves distinctly large, 28–30 cm long, lyrate; segments in 2–3 pairs, terminal segments distinctly larger, broadly lanceolate, 10–11 × 4–5 cm, denticulate, lateral segments oblong or oblong-lanceolate, 8–16 mm wide, entire, petiole up to 16 cm long, acute at apex. Lower cauline leaves large, 24–26 cm long, lyrate; segments in 2–4 pairs, terminal segments distinctly larger, lanceolate, 9–10 × 2–2.8 cm, denticulate or entire, lateral segments oblong, 5–10 mm wide, entire, petiolate, up to 8 cm long, acute at apex. Median cauline leaves subsessile, 9–18 cm long, lyrate; segments in 2–3 pairs, terminal segments much larger, broadly lanceolate or lanceolate, 9–10.5 × 2–2.5 cm, entire or remotely denticulate, lateral segments oblong, 4–12 mm wide, acute at apex. Upper cauline leaves increasingly smaller, sessile, 1–7 cm long, sublyrate or with 2–3 lobes in lower part, sometimes simple, segments oblong or oblonglanceolate or narrowly lanceolate, entire, acuminate at apex. Capitula solitary at end of branches, peduncle 10–50(–53) mm long; involucres ovoid, rounded at base, 15–16 × 14–17 mm. Phyllaries multiseriate, coriaceous-herbaceous, green, glabrous and smooth. Outer phyllaries ovate, 2–4.2 × 2.5–4 mm; median phyllaries oblong, 8–10 × 5.5–6 mm; inner phyllaries oblong, 11–14 × 5.2–6 mm, with hyaline border. Appendages very small, concealing only minor part of phyllaries, straw-coloured with pale brown that is more intensive in the central part, semilunar or shortly triangular, not decurrent, the inner ones sometimes suborbicular, spineless, 2–3(–3.5) mm wide at base (cilia excluded); cilia whitish, short, numerous, 4–8 on each side, 0.3–2 mm long, erect or subundulate. Flowers pink-purple; central florets hermaphrodite, ca. 21–22 mm long, with 5 lobes equal and acute, with deeply brown nerves, tube yellow, anther tube slightly longer than corolla, apical appendages acute, stigma deeply purple, strongly longer than corolla, up to 7 mm, symmetrically bifid, 0.2–0.3 mm long, pubescent; peripheral florets sterile, 4-lobed, limb lobe linear, 7–7.5 mm long, scarcely radiant. Achenes oblong, ca. 4.2 mm long, ca. 2.2 mm wide, yellow, smooth and shiny, adpressed white hairy; hilum lateral, 0.4–0.5 mm long, long-barbellate. Pappus double, scabrous, pale brown; outer setae 7–7.5 mm long; inner shorter, 1.3–2.5 mm long.

Etymology: —The specific epithet refers to Sanandaj city, where the new species was found.

Distribution and habitat: — Centaurea sanandajensis occurs scattered between oak trees on clayey mountains in Kurdestan Province, W Iran (Fig. 3). This species is an Irano-Turanian element. It is a sciophyte species that grows among decaying leaves at elevations of 1300–1500 m. In addition, some other plants that occurred in the area were Avena barbata subsp. barbata, Zoegea leptaurea, Astragalus procerus, Phlomis lanceolata, Centaurea aggregata subsp. aggregata, Heliotropium lasiocarpum.

Relationships: — Centaurea sanandajensis belongs to C. sect. Acrocentron, which includes taxa with stems usually branched in the upper part, leaves lyrate or pinnatisect to bipinnate, not decurrent, with few medium-sized or large capitula, oblong-ovoid to subglobose involucres, and decurrent appendages ending to a spine. This species is very interesting because it is the only spineless species of C. sect. Acrocentron in Iran. It is similar to C. longipedunculata, which is endemic to Iraq, in plant indumentum, color of flowers and length of pappus (Figs. 4 and 5), but differs in some important characters (see Table 1).

In addition, C. sanandajensis is similar to C. persica Boissier (1845: 132) in color of appendages and flowers. The latter species is native to SE, C and W Iran, with some populations occuring in E Turkey (Fig. 3). However, C. sanandajensis differs from it by its stem glabrous (vs. long-hirsute in lower part, otherwise glabrous or scabrous), leaves glabrous (vs. sparsely long-pilose-articulate below, glabrous or sparsely hirsute above), terminal segments of leaves lanceolate to broadly lanceolate (vs. rhombic or lanceolate), involucres ovoid, rounded at base, 15–16 × 14–17 mm (vs. oblong or subglobose, truncate at base, 20–25(–27) × 16–23 mm), appendages spineless and not decurrent, 2–3(–3.5) mm wide at base (cilia excluded) (vs. included spine 10–20(–27) mm long, decurrent, 4–5 mm wide at base (cilia excluded), cilia 0.3–2 mm (vs. (3–)4–5(–6) mm) long, and also achenes ca. 4.2 mm (vs. 5–7 mm) long.

Key to the species of Centaurea sect. Acrocentron in Iran with straw-coloured appendages and pink-purple flowers

1 Plants biennial; stem often branched in lower part, floccose-arachnoid-tomentose; pappus (8–) 9–14 mm long......... ........................................................................................................................................ C. urvillei subsp. deinacantha

- Plants perennial; stem little branched in upper part, sometimes dichotomous, not floccose; pappus (5–) 7–9 mm long...................................................................................................................................................................................... 2

2 Involucres 25–30 mm wide; appendages usually totally concealing of phyllaries, (5–) 6–7 mm wide at base (cilia excluded); cilia (10–)12–15 on each side ............................................................................................. C. ochrocephala

- Involucres 14–23 mm wide; appendages not totally concealing of phyllaries, 2–5 mm wide at base (cilia excluded); cilia 4–8(–10) on each side........................................................................................................................................... 3

3 Plant often 25–60 cm tall; stem hirsute in lower part; leaves sparsely long-hirsute; involucres truncate at base.......... ........................................................................................................................................................................ C. persica

- Plant ca. 70–90 cm tall; stem glabrous; leaves glabrous; involucres rounded at base................................................. 4

4 Involucres oblong, 22–25 mm long; appendages concealing a major part of phyllaries, triangular, decurrent; spine 5– 8 mm long; cilia 3–6 mm long ....................................................................................................... C. longipedunculata

- Involucres ovoid, 15–16 mm long; appendages concealing a minor part of phyllaries, sublunar or narrowly triangular, not decurrent; spineless; cilia 0.3–2 mm long ............................................................................... C. sanandajensis