Heliotropium khayyamii Akhani, 2016

Memariani, Farshid, Akhani, Hossein & Joharchi, Mohammad Reza, 2016, Endemic plants of Khorassan-Kopet Dagh floristic province in Irano-Turanian region: diversity, distribution patterns and conservation status, Phytotaxa 249 (1), pp. 31-117 : 41-44

Heliotropium khayyamii Akhani , sp. nov. ( Fig. 6–8 ), Map 137.

Typus: — IRAN. Khorassan (Razavi): 32 km NWN of Neyshabur, 3 km from Arieh towards Derakhte Jowz , on marl hills, 36°26’33”N, 58°43’37” E, 1693 m.a.s.l., 14.07.2013, H. Akhani 24032 (holotype IRAN; isotypes FUMH, Hb. Akhani) .

Plants annual, 6–30(–60) cm long, erect, non-branched from base, slightly branched from the middle of the stem; stems grey, densely pilose to subtomentose, hairs retrorsely subappressed, 0.3–0.6 mm long, intermixed with a few patent or slightly upward hairs up to 1 mm long; leaves ovate-orbicular, 17–35 mm long, 16–37 mm wide, obtuse at apex, truncate at base, upper surface greenish, sparsely appressed pilose, lower surface densely patent pilose, margins entire, nerves depressed at upper and prominent at lower surfaces, petioles 1–2 cm long, inflorescences terminal and lateral, unilateral to slightly bilateral, 4–12 cm long, c. 10–26-flowered, terminal branches 2–3-forked; flowers ± sessile; calyx segments oblong, divided nearly to base, 2.2–3 × 0.9–1.5 mm, outside covered by slightly upwards directed tuberculate hairs, 0.26–0.43 mm long, inside pilose with appressed hairs; corolla tubulate, constricted in throat, expanded in lower part, 2.5–2.7 mm; corolla lobes plicate, without distinct intercalary lobes, lobes semi-circular, 0.4–0.6 mm long, 0.63–0.65 mm wide, obtuse, anthers located in 0.6–0.7 mm above corolla base, 1.1–1.2 mm long, apex slightly acute, non-apiculate, style invisible, hidden by stigmatic disc; stigma conical, 0.7–0.78 mm long, with a stigmatic base of 0.65–0.67 mm, bi-lobed at apex, slightly hairy in conical receptive part, style invisible. nutlets elliptic, (1.7–)2–2.5 × 1–1.3 mm; smooth or with 1–2 indistinct striae on surface.

Affinity: —Considering its very small flowers, this species has similarities with some small-flowered species of the NE Iranian and Turkmenian flora such as H. disciforme Akhani (1991: 569) , H. litvinovii Popov (1931: 218) and H. mesinanum Bunge (1869: 313) . It differs from H. disciforme by an elongate stigma (vs. disk-like), from H. litvinovii by sessile flowers (vs. pedicelled) and a shorter stigma, and from H. mesinanum by an appressed indumentum (vs. patent) and an invisible style (vs. distint). Furthermore, the corolla segments are elongate and acute in H. mesinanum in contrary to orbicular and obtuse lobes in H. khayyamii . The unpublished nuclear and chloroplast sequence data (Akhani, Chase, Frohlich & Mahdavi) clearly separate H. khayyamii from all other species to form its own branch in a large polytomy.

Additional specimens studied: — NE IRAN: Khorassan Razavi: NW of Neyshabur, between Derakht-e Jooz and Arieh , 36°26 ʹ N, 58°44 ʹ E, 1850 m, 25.06.2002, Joharchi & Zangooei 34291 ( FMUH, Hb. H. Akhani) ; 32 km NW Neyshabur, marl soils near Damenjan village, 36°26 ʹ 48 ʺ N, 58°39 ʹ 11 ʺ E, 1498 m, 14.07.2013, H. Akhani 24020 ( Hb. H. Akhani) ; Northern Khorassan Province: ca. 85 km NW of Bojnurd, near Dashtak, gypsum hills and partly ruderal saline soils, 37°44 ʹ 25 ʺ N, 56°38 ʹ 56 ʺ E, 490 m, 10.10.2012, H. Akhani 23271 ( Hb. H. Akhani) ; 80 km WNW of Bojnurd, c. 10 km E of Kalateh Dashtak, on the foothills of Booz Daghi Mountain, on shiel and sandy, 37°47 ʹ 38 ʺ N, 56°39 ʹ 19 ʺ E, 714 m, 15.07.2013, H. Akhani 24037 ( Hb. H. Akhani) ; 80 km WNW of Bojnurd, c. 10 km ESE of Kalateh Dashtak, marl hills along Atrak river, 37°44 ʹ 37 ʺ N, 56°37 ʹ 59 ʺ E, 505 m, 15.07.2013, H. Akhani 24057 ( Hb. H. Akhani) ; 81 km WNW of Bojnurd, c. 9 km SE of Kalateh Dashtak, marl hills along Atrak river, 37°44 ʹ 42 ʺ N, 56°36 ʹ 30 ʺ E, 496 m, 15.07.2013, H. Akhani 24060 ( Hb. H. Akhani) .

Distribution and habitat: —The new Heliotropium was found in a few localities in NW of Neyshabur and disjunctly further North along Atrak river close to Turkmenian border (Appendix II, Map 137). The habitat of this species is clay-gypsum and marl hills. Such habitats are usually species-poor, very often with a good representation of several local endemics. In more disturbed areas around the roads some ruderal species may occupy such habitats. The associated species with H. khayyamii are listed in Tab. 4 based on three plots.

Ethymology: —The species epithet “ khayyamii ” honours a Persian astronomer, mathematician and poet of 12th

Century, Hakim Omar Khayyam from Neyshabur.

Figures

FIGURE 6. Heliotropium khayyamii in type locality. a. Habit and habitat on marl steep slopes; b–c. Close-up of inflorescence.