Centaurea jiroftensis (Ranjbar & Negaresh) Ranjbar & Heydari, 2016

Ranjbar, Massoud & Heydari, Razayeh, 2016, A taxonomic contribution to yellow-flowered members of Centaurea sect. Phaeopappus (Asteraceae) in Iran, Phytotaxa 277 (2), pp. 182-190 : 183-184

1. Centaurea jiroftensis (Ranjbar & Negaresh) Ranjbar & Heydari , comb. & stat. nov.

Basionym:— Centaurea phaeopappa subsp. jiroftensis Ranjbar & Negaresh (2013: 29) .

Diagnosis:—The new species is closest to Centaurea phaeopappa in segmentation of leaves, size of cilia and spines and colour of flowers, but it differs from the latter in indumentum densely floccose-tomentose (vs. loosely floccose-tomentose its height), up to 16 cm (vs. 25–45 cm) tall, densely foliate (vs. loosely foliate), upper stem leaves slightly longer than capitula (vs. shorter than capitula), synflorescence 2–3-cephalous (vs. to 6-cephalous), involucre 29–33 × 35–40 (vs. 20–25 × 20–25) cm, peduncle sessile (vs. 10 mm long), median phyllaries up to 20 (vs. 7–13 long).

Type:— IRAN. Prov. Kerman: Jiroft toward Kerman, 10 km after Jiroft, 1450 m, 30°17 ʹ 2 ʺ N, 57°5 ʹ E, 3 June 2011, Ranjbar & Negaresh 24214 ( BASU!, holotype).

Perennial plants, usually completely greyish-white, with long woody rhizome bearing string-like roots, up to 16 cm tall. Stem erect, branched at base, branches equal in length, rigid, striate, ca. 3.5 mm in diam. at base, densely floccose-tomentose. Leaves always divided, pinnatisect to pinnatipartite, rarely bipinnate, densely floccose-tomentose on both sides. Basal stem leaves petiolate (petioles 4–5.2 cm long), usually longer than stem, pinnatisect to pinnatipartite, segments in 11–13 pairs, linear, terminal segment slightly longer than lateral, segments entire or with 1–2 pairs of lobes, acuminate at apex. Lower stem leaves petiolate (petioles 2.8–4.5 cm long), pinnatisect to pinnatipartite, segments in ca. 15 pairs, linear, terminal segment slightly longer than lateral, segments entire or with 1–3 pairs of lobes, acuminate at apex. Median stem leaves sessile, pinnatisect, segments in ca. 10 pairs, linear or narrowly lanceolate, entire or with 2–3 pairs of lobes, acuminate at apex. Upper stem leaves sessile, pinnatisect, sometimes pinnatifid, segments in 1–4 pairs, linear, entire, acuminate or mucronate at apex, slightly longer than capitule. Capitule 2–3 on sessile peduncles, solitary at end of branches; involucres ovoid, large, 29–33 × 35–40 mm. Phyllaries multiseriate, imbricate, coriaceous, greenyellow, glabrous and smooth. Outer phyllaries oblong, oblong-ovate, 3–8 × 3–6 mm; appendages narrowly ovate, straw-coloured, pale brown in central part, 10–17 × 7–12 mm (cilia and spine included). Median phyllaries broadly ovate to oblong, 10.5–12 × ca. 9 mm; appendages triangular or broadly ovate, deep brown in central part, ca. 21 × 13– 15 mm (cilia and spine included). Inner phyllaries broadly oblong to oblong, 16.5–22 × 8–10 mm, sometimes margin membranous; appendages ovate or suborbicular, deep purple in central part, ciliate or lacerate, 6–15 × 5–10.5 mm (cilia and spine included). Appendages concealing a major part of phyllaries, moderately imbricate, pectinate-ciliate or lacerate, sometimes shortly decurrent on crenate margins; cilia white or pale brown, narrowly triangular, distinct, numerous, (6–)8–16 on each side, 1.2–5 mm long; spine narrowly triangular, 5.5–10 mm long, white or straw-coloured to brownish, much longer than the nearest cilia. Flowers yellow; central florets hermaphrodite, ca. 28 mm long, corolla with purple nerves, 5-lobed, lobes ca. 10 mm long, anther tube purple (in dry state pink); peripheral florets sterile, finely dissected, ca. 32 mm long, not radiant, 4-lobed, limb lobes filiform, ca. 8 mm long. Achenes immature; pappus persistent, multiseriate, scabrous, ca. 20 mm long, innermost series not longer than others.

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

Paratype: — IRAN. Prov. Fars: Larizangan village, 1835 m, 30 April 2011, Ranjbar & Negaresh 24558 (BASU!).

Habitat, ecology and climate: —The new species grows in a clay stone area. In addition, accompanying species were Avena barbata subsp. barbata , Aegilops kotschyi , Bromus racemosus , Echinops ceratophorus , Ficus carica , and Amygdalus sp. Jiroft’s climate is a desert one. There is virtually no rainfall all year long in Jiroft. This climate is considered to be BWh according to the Köppen-Geiger climate classification. Precipitation here averages 82 mm.

Taxonomic and distributional remarks: — Centaurea jiroftensis is a rare endemic of SE Iran, known only from the stony area in Kerman and Fars Provinces, far from the main distribution area of C. phaeopappa . It is similar to C. phaeopappa in segmentation of leaves, size of cilia and spines, and colour of flowers, but differs in some important characters (see Table 1).

Chromosome numbers: —Unknown.