Centaurea saeidii Negaresh, 2025

Negaresh, Kazem & Yousefi, Zohreh, 2025, A new species of Centaurea sect. Cynaroides (Asteraceae, Cardueae-Centaureinae) from Iran, Phytotaxa 690 (2), pp. 267-275 : 268-272

Centaurea saeidii Negaresh , sp. nov. ( Figs. 1 , 2 )

Type: — IRAN. Prov. Kermanshah: Ravansar toward Javanroud, 2–3 km after Ravansar, fallow field, 34° 45′ 32.2″ N, 46° 37′ 54.3″ E, 1380–1400 m, 15 June 2017, Negaresh 325 (holotype KHAU!, isotype FUMH!, KHAU!).

Diagnosis: — Centaurea saeidii is related to C. amadanensis subsp. amadanensis , from which it differs mainly in its middle cauline leaves broadly oblanceolate (vs. broadly lanceolate, oblong to oblong-subpandurate), involucres subglobose, 35–40 × 35–40 mm (vs. ovoid or obconical, 25–35 × 22–30 mm), phyllaries tomentose (vs. floccose-tomentose), inner phyllaries 25–30 mm (vs. 12–18 mm) long, appendages brown, 2–3 mm wide at base (vs. straw-coloured, 1–2 mm wide at base), flowers purple, 46–48 mm long (vs. white, 38–40 mm long), peripheral florets numerous (ca. 15 in each capitulum) and conspicuous (vs. few (1–3 in each capitulum) and inconspicuous, achenes 8.5–9 mm (vs. 7–8 mm) long.

Descriptions: —Biennial plants, with thick freshly taproot, whole plant usually green, 60–80 cm tall; collum neck with fibrous remnants of petioles from the previous year. Stem erect, usually simple, 10–12 mm in diam. at base, cylindrical, with thick yellow striations, densely leafy in the lower part, lower part with loose deciduous hirsute-articulate hairs (up to 2 mm long), median part loosely arachnoid with hirsute-articulate hairs, upper part with loose arachnoid hairs. Leaves rigid, papyraceous (on drying), sparsely covered with hirsute-articulate hairs, densely so on midrib and veins, up to 1.5 mm long, and glandular hairs. Basal leaves withered at anthesis. Lower cauline leaves simple, almost withered at anthesis, subcordate to broadly ovate, 20–30 × 12–13 cm, with a 6–10 cm long petiole, obtuse to subacute at apex, margin scabrous or cartilaginously denticulate. Median cauline leaves sessile, simple, broadly oblanceolate, 15–18 × 10–12 cm, winged or broadly decurrent, up to 60 mm along stem, acute at apex, margin scabrid, sometimes denticulate. Upper cauline leaves sessile, simple, lanceolate, 8–15 × 2.5–5 cm, loosely covered with arachnoid, sometimes mixed with scattered hirsute-articulate hairs, decurrent up to 20 mm along stem, acuminate at apex, margin smooth. Capitula several, 8 to 10, arranged in racemes, upper capitula on peduncles 3–10 cm long. Involucres subglobose, 35–40 × 35–40 mm. Phyllaries multiseriate, green in vivo, yellow-greenish in sicco, imbricate, coriaceous-scarious, densely tomentose hairs, with hyaline margins. Appendages rigid, concealing part of phyllaries only, spiniform or elongate triangular, entire, sometimes with 1 to 3 cilia, brown, 2–3 mm wide at base, not decurrent. Outer phyllaries ovate, 5–10 × 3–6 mm, appendages 3–10 mm long. Median phyllaries lanceolate, 15–30 × 8–15 mm, appendages 12–18 mm long. Inner phyllaries narrowly lanceolate or linear, 25–30 × 4–7 mm, appendages lacerate. Flowers purple; central florets hermaphroditic, 46–48 mm long, corolla ca. 18 mm long, 5-lobed, lobes ca. 6 mm long, with brownish nerves, anthers pale purple, shorter than corolla, with apical appendages acute, stigma exserted from corolla up to 3 mm; peripheral florets sterile, finely dissected, not radiant, shortly than central ones, numerous (ca. 15 in each capitulum) and conspicuous, 5-lobed, limb lobe filiform, lobes ca. 7 mm long. Achenes oblong, 8.5–9 mm long, 3.2–3.5 mm wide, smooth and shiny, whitish, rounded at apex, glabrescent; insertion areole lateral, ca. 1 mm long. Pappus persistent, multiseriate, scabrous, whitish, 14–16 mm long, bristles of inner rows very slightly longer than others.

Etymology: —The specific epithet is given in honour of Dr. Hojjatollah Saeidi, who worked on various genera of the family Poaceae .

Phenology: —Flowering from May to June and fruiting from June to July.

Paratypes: — IRAN. Prov. Kermanshah: Ravansar, 2 km from Ravansar toward Kamyaran, 34° 43′ 55.7″ N, 46° 46′ 32″ E, 1345 m, 15 June 2017, Negaresh 324 (KHAU!, FUMH!).

Conservation status: — Centaurea saeidii is known only from the type locality.After detailed field investigations, no other population was found in the surrounding area. The only known population covers an area of ca. 1000 m 2 and consists of ca. 90 individuals. Possible threats include deterioration of habitats (erosion), the location near a human settlement and restricted distribution. According to the IUCN red list categories and criteria ( IUCN 2012), C. saeidii should be considered ‘Critically Endangered’ (CR) [criterion B2ab].

Distribution, habitat and ecology: — Centaurea saeidii is a rare endemic of Kermanshah Province, W Iran ( Fig. 3 ). It is an Irano-Turanian element, and grows on roadsides and fallow fields, at elevations of 1300–1400 m ( Fig. 1 ). In addition, some other plants that occurred in the area were Avena barbata subsp. barbata , Bromus tectorum , Centaurea behen , Centaurea solstitialis subsp. solstitialis , Cephalaria syriaca , Hordeum marinum , Marrubium vulgare , Onobrychis melanotricha , Phlomis persica , Pisum sativum , Salvia syriaca, Xerathemum longipapposum, Zoegea leptaurea .

Relationships: — Centaurea saeidii belongs to C. sect. Cynaroides , which includes taxa with racemose or dichasial synflorescences, decurrent upper cauline leaves, ovoid to subglobose involucres, triangular to ovate or orbicular appendages, not decurrent, and usually ciliate and ending in a firm spine or spinule, and with pink, purple or yellow flowers ( Negaresh & Rahiminejad 2018). It is similar to C. amadanensis subsp. amadanensis , from SW to W Iran and NE Iraq ( Fig. 3 ), in the indumentum of leaves, shape of appendages, shape of achenes and status of pappus ( Fig. 4 ), but differs in some important characters (see Table 1).

Centaurea saeidii is also similar to C. kabirkuhensis Mozaffarian, F. Ghahremaninejad & Fereidounfar (2012: 133) , which is endemic to W Iran ( Fig. 3 ), especially because of the arrangement of capitula, indumentum of phyllaries and status of peripheral florets. However, it differs from C. kabirkuhensis in some characters like shape of lower and median cauline leaves, shape and size of involucres, length of inner phyllaries, color, shape and width of appendages, length of achenes, length and status of pappus ( Table 1).

two latter taxa from Negaresh & Rahiminejad 2018 and field observations).

Figures

FIGURE 1. Centaurea saeidii Negaresh (Negaresh 325, KHAU). A. Close up of capitulum. B. Habit and habitat. C. Achene with pappus. Scale A = 2 cm, B = 4 cm, C = 5 mm.

FIGURE 2. Centaurea saeidii Negaresh (Negaresh 325, KHAU). A. Upper cauline leaves. B. Median cauline leaves. C. Indumentum of lower part of stem. D. Taproot. Scale A = 5 cm, B = 6 cm.

FIGURE 3. Distribution of Centaurea saeidii (triangle), C. amadanensis subsp. amadanensis (squares), and C. kabirkuhensis (circles).

FIGURE 4. Centaurea amadanensis Schultz Bipontinus subsp. amadanensis (Negaresh & Asadbegy 119, KHAU). A. Habit and habitat. B. Close up of capitulum. Scale A = 3 cm, B = 1 cm.