Centaurea alfonsoi Negaresh (2014: 195)

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

1. Centaurea alfonsoi Negaresh (2014: 195) . Type:— IRAN. Prov. Kermanshah: Kamyaran, 5 km to Ravansar , 1400– 1420 m, 31 June 2012, Ranjbar & Negaresh 28688 (holotype BASU!, isotype BASU!, photo herb. Negaresh). ( Fig. 1 )

Biennial plants, with thick freshly taproot, whole plant usually green, 100–150 cm tall; collum neck with fibrous remnants of petioles from previous year. Stem erect, usually simple, 10–15 mm in diam. at base, cylindrical, with thick white striations, densely leafy in median part, lower to median parts ± densely covered with hirsute-articulate hairs and sessile glands, upper part sparsely arachnoid up to 1.5 mm long, and sessile glands hairs. Leaves rigid, papyraceous (on drying), loosely covered with hirsute-articulate hairs, densely on midrib and veins, up to 0.8 mm long, and glandular hairs. Basal leaves withered at anthesis. Lower cauline leaves simple, almost withered at anthesis, subcordate to broadly ovate, 22–34 × ca. 16–17 cm, with a 7–13 cm long petiole, sometimes with basal auricles, obtuse to subacute at apex, margin scabrous or cartilaginously denticulate. Median cauline leaves sessile, simple, broadly oblanceolate or broadly lanceolate, 19–28 × 10–17 cm, winged or broadly decurrent, up to 60 mm along stem, acute at apex, margin scabrid, sometimes denticulate. Upper cauline leaves sessile, simple, lanceolate or lanceolate-elliptic, 3–14 × 0.8–5 cm, loosely covered with arachnoid, sometimes mixed with scattered hirsute-articulate hairs, acute or cuspidate at apex, margin subscabrous, narrowly decurrent. Capitula numerous, 10 to 15, arranged in racemes, upper capitula on peduncles 13–20 cm long, sometimes with bracts similar to phyllaries with small stramineous and chaffy appendages. Involucres ovoid to subglobose, (25–)35–40 × 35–40 mm. Phyllaries multiseriate, green in vivo, yellow-greenish in sicco, imbricate, coriaceous-scarious, densely tomentose with hairs 0.2–0.3 mm long; appendages small, concealing part of phyllaries only, chartaceous and rigid, straw-coloured or pale brown-reddish, sometimes brownish, sometimes acute at apex or appendiculate; cilia short, sometimes cilia very few or lacking; spine erect, longer than adjacent cilia, rarely very short and mucronate. Outer phyllaries broadly oblong, 5–9.5 × 7.5–10 mm; appendages triangular-ovate, 8–10 × ca. 9–10 mm (including cilia and spine), narrowly decurrent, with 8–12 cilia on each side, 0.3–1.5 mm long, sometimes denticulate, gradually narrowing into a 1–2 mm spine. Median phyllaries broadly ovate, ca. 12 × 10–13 mm; appendages triangular, 11–13 × ca. 10–11 mm (including cilia and spine), not decurrent, with 3–5(–6) cilia on each side, 1.5–3 mm long, gradually narrowing into a 5–7 mm spine. Inner phyllaries broadly ovate to lanceolate or broadly lanceolate, 17–28 × 9–13 mm; appendages lanceolate to narrowly lanceolate, 8–16 × 4–10 mm (including cilia and spine), not decurrent, with 2–4 cilia on each side, 1.5–3 mm long, gradually narrowing into a 5–9 mm spine. Flowers white in vivo, pale yellow in sicco; central florets hermaphroditic, 46–48 mm long, corolla ca. 18 mm long, 5-lobed, lobes ca. 10 mm long, with brownish nerves, anther tube pink; peripheral florets sterile, finely dissected, not radiant, nearly equal to central ones, numerous (ca. 20 in each capitulum) and conspicuous, 4–5-lobed, limb lobe filiform, lobes ca. 8 mm long. Achenes oblong, 9–10 mm long, 3.2–3.8 mm wide, smooth and shiny, whitish, rounded at apex, glabrescent; insertion areole lateral, ca. 1 mm long. Pappus persistent, multiseriate, scabrous, whitish, 12–14 mm long, bristles of inner rows very slightly shorter than others.

Taxonomic and distribution remarks: — Centaurea alfonsoi is endemic to Kermanshah Province, W Iran ( Fig. 2 ). It is an Irano-Turanian element, and distributed around Shahu Mountains. Centaurea alfonsoi is known only along roadsides and fallow fields, at elevations of 1350–1450 m ( Figs. 1D and 3D ). It is similar to C. karamianiae in its indumentum of leaves, color of flowers and length of achenes and pappus. However, C. alfonsoi differs from C. karamianiae by its stem 100–150 cm (vs. 160–180 cm) tall, lower cauline leaves almost withered at anthesis, subcordate to broadly ovate, 22–34 × ca. 16–17 cm (vs. never withered, broadly cordate-ovate or broadly cordate-lanceolate, 42–50 × 19–26 cm), capitula 10 to 15-cephalous (vs. 24 to 26-cephalous), outer appendages with 8–12 cilia on each side, 0.3–1.5 mm long, sometimes denticulate, gradually narrowing into a spine 1–2 mm long (vs. with 4–5 cilia on each side, 0.5–2.5 mm long, gradually narrowed into a spine 4–5 mm long), median appendages with 3–5(–6) cilia on each side, 1.5–3 mm long (vs. with 2–3 cilia on each side, 1–2 mm long, or entire), flowers 46–48 mm (vs. ca. 55 mm) long, anther tube pink (vs. white), and also peripheral floret nearly equal to central ones, numerous (ca. 20 in each capitulum) and conspicuous (vs. shorter than central ones, very few (1–3 in each capitulum) and very inconspicuous).

Chromosome numbers: —Negaresh et al. (2014) reported the chromosome number 2 n = 2 x = 18 for Centaurea alfonsoi collected from the type locality. This is the only count for this taxon.

Selected specimens examined:— IRAN. Prov. Kermanshah: Ravansar toward Javanroud, 5 km after Ravansar , 1415 m, 27 May 2014, Negaresh & Kamalnejad 19634 ( HUI!, BC!, herb. Negaresh!); Ravansar toward Kamyaran, 1–3 km after Ravansar, 1375 m, 29 May 2014, Negaresh & Kamalnejad 150 (herb. Negaresh!, RUH!); Negaresh & Kamalnejad 153 (herb. Negaresh!); Negaresh & Kamalnejad 154 (herb. Negaresh!); Javanroud toward Ravansar, 5 km to Ravansar, 1430 m, 27 May 2014, Negaresh & Kamalnejad 151 (herb. Negaresh!) .

Figures

FIGURE 1. Centaurea alfonsoi Negaresh (Ranjbar & Negaresh 28688, BASU). A˗C. close up of capitula with pollinators. D. habit and habitat. Scale A˗C = 2 cm, D = 6 cm.

FIGURE 2. Distribution of Centaurea alfonsoi (circles) and C. aladaghensis (squares).

FIGURE 3. Different habitats on the Centaurea sect. Cynaroides. A. C. imperialis. B. C. regia. C. C. nemecii. D. C. alfonsoi. E and F. C. amadanensis.