Persepolium O.V.Yurtseva & E.V.Mavrodiev, 2017

Yurtseva, Olga V., Severova, Elena E. & Mavrodiev, Evgeny V., 2017, Persepolium (Polygoneae): A new genus in Polygonaceae based on conventional Maximum Parsimony and Three-taxon statement analyses of a comprehensive morphological dataset, Phytotaxa 314 (2), pp. 151-194 : 185

Persepolium O.V.Yurtseva & E.V.Mavrodiev , gen. nov.

≡ Polygonum subsection Suffruticulosa Meisner (1857: 89) .

≡ Polygonum subsection Spinescentia Boissier (1879: 1027) .

≡ Atraphaxis section Polygonoides Tavakkoli et al. (2015: 1167) .

Lectotype (designated here):— Persepolium salicornioides (Jaub. & Spach) O.V.Yurtseva & E.V.Mavrodiev ≡ Polygonum salicornioides Jaubert & Spach (1844 –1846 [1845]: tab. 123).

Description: —Small caespitose undershrubs or dwarf shrubs 10–30 cm tall with erect and intensively branched wiry terete densely velutinous-puberulent glaucous annual shoots. Leaf blades linear-lanceolate, obtuse or shortly acuminate, revolute at margin, puberulent adaxially and abaxially, almost sessile, jointed with articulation, ±deciduous or rarely persistent. Ocreas are 2–4(7) mm long, membranous, transparent, truncate-tubular or acuminate-tubular, bifid, later bilacerate, without veins, or with 2–6 veins. Thyrses terminal, leafy, with 10–15 clusters of 1–2(3) flowers. Perianth urceolate or campanulate, 2–6 mm long, fully densely shortly puberulent, divided to 2/3–3/ 4 in five equal-sized segments. Segments oblong-elliptical or oblong-ovate, leathery, rigid, purplish-green, with a narrow (less than 0.2 mm) membranous margin, not enclosing the achene. Stamens 8. Styles 3, stigmas linear, slightly inflated to the top. Achene 2.5–5.0 × 2.0– 2.8 mm, ovoid, trigonous, acuminate, minutely tuberculate or smooth. Pollen tricolporate, prolate to subprolate (P/E = 1.4–1.9), elliptical in equatorial view, trilobed-circular in polar view, exine tectate, sporoderm ornamentation microreticulate-foveolate, foveolate-perforate, perforate, or striate-perforate.

Distribution: — IRAN. Endemic of the Zagroz Mountains.

Etymology: —The genus is named for Persepolis, an ancient capital of Persia.

Affinity: —Caespitose habit and wiry terete shoots with fleshy linear-lanceolate early deciduous leaf blades differentiate Persepolium from shrubby species of Polygonum and Atraphaxis . Persepolium resembles some Polygonum species and some Atraphaxis species ( A. ariana , A. atraphaxiformis , A. toktogulica , A. tortuosa ) by the campanulate or urceolate perianth with five equal-sized segments, but differs by the coriaceous and fully densely velutinous-puberulent perianth, and frondose or frondulose thyrses.

The genus Persepolium includes at least five endemics of SW and Central Iran.