Centaurea elegantissima Bornm., 1928

Ranjbar, Massoud & Negaresh, Kazem, 2013, A contribution to Centaurea sect. Acrocentron (Asteraceae) from Iran, Phytotaxa 149 (1), pp. 50-60 : 58-59

Centaurea elegantissima Bornm. descr. compl. Fig. 6

Achaenia oblonga, 5.5–6 mm longa, 2–2.2 mm lata, lutea, dense pilosa, hila lateralia barbata et ca. 0.6 mm longa; pappus scaber, albidus, ca. 10–11 mm longus, internus 2.5–3 mm longus.

Type :— IRAQ. Prov. Kurdestan: Sakri Sakran mountains near Rawandiz, 1500 m, Bornmüller 1489 (holotype B!) .

Achenes oblong, 5.5–6 mm long, 2–2.2 mm wide, yellow, smooth and shiny, adpressed white hairy; hilum lateral, ca. 0.6 mm long, long-barbellate. Pappus double, scabrous, whitish; outer ca. 10–11 mm long; inner shorter, 2.5–3 mm long.

Specimen examined: — IRAN. Prov. Kurdestan: Marivan , first road beginning Dezli, 1295 m, 20 July 2012, Ranjbar & Negaresh 31631 ( BASU!) .

Distribution and habitat: — Centaurea elegantissima occurs in mountains Dezlei, around Marivan in Kurdestan Province, W Iran ( Fig. 3 ). It grows on gravelly and rocky mountain slopes or scattered between shrubs of Pistacia atlantica , at elevations of 1200–1350 m. Centaurea elegantissima is an Irano-Turanian element. In addition, some other plants that occurred with the species are Avena barbata subsp. barbata , Centaurea behen , Centaurea amadanensis var. gymnoclada , Zoegea crinita , Centaurea aggregata subsp. aggregata , Stachys kurdica , Silene latifolia , Pistacia atlantica , Onosma sp.

Relationships: — Centaurea elegantissima makes a new record from Iran ( Fig. 3 ). The species was collected once by Bornmüller about 84 years ago in the Sakri Sakran mountains in E Iraq. Previously C. elegantissima was considered endemic to Iraq ( Wagenitz 1980). It is similar to C. kandavanensis , endemic to N Iran, in shape of appendages, indumentum of phyllaries and length of achenes, but differs from this species by its stem erect and thick (vs. robust and slender), up to 50 cm (vs. up to 90 cm) tall, subglabrous (vs. pilose in lower part, otherwise ± glabrous), leaves subglabrous (vs. pilose), involucres hemispherical (vs. subglobose) and ca. 30 × 35 mm (vs. (20–)25–35 × 20–35 mm), phyllaries green (vs. purple-tinged), appendages (spine included) 13–18 mm (vs. 15–30 mm) long, flowers pink-purple (vs. dark purple), and also pappus ca. 10–11 mm (vs. (4–)6–8(–10) mm) long.

Chromosome number report: — Centaurea elegantissima is a diploid species with the base chromosome number of 2 n = 2 x = 22, which is consistent with the proposed base number of x = 11 for the section. This is the first chromosome report for this species ( Fig. 6D ).

Figures

FIGURE 3. Distribution of Centaurea sanandajensis (1), C. elegantissima (2), C. urvillei subsp. deinacantha (3), C. ochrocephala (4), and C. persica (6) in west Asia based on herbarium specimens in BASU, E, G, JE, LD, P, PR, VAN, W and WU.

FIGURE 6. Centaurea elegantissima Bornm. (Ranjbar & Negaresh 31631, BASU). A. fertile achene. B–C. sterile achenes. D. metaphase plate (2n = 22). E. capitulum. F. upper cauline leaves. G. habit. H. indumentum of leaves. Scale A = 2 mm, B–C = 1.5 mm, E–F and H = 1 cm, G = 3 cm.