Phytotaxa 314 (2): 151–194 ISSN 1179-3155 (print edition) http://www.mapress.com/j/pt/ PHYTOTAXA Copyright © 2017 Magnolia Press Article ISSN 1179-3163 (online edition) https://doi.org/10.11646/phytotaxa.314.2.1

Persepolium (Polygoneae): A new genus in Polygonaceae based on conventional Maximum Parsimony and Three-taxon statement analyses of a comprehensive morphological dataset

OLGA V. YURTSEVA1*, ELENA E. SEVEROVA1 & EVGENY V. MAVRODIEV2 1Department of Higher Plants, Faculty of Biology, M.V. Lomonosov Moscow State University, 1–12, Leninskie Gory, 119234, Moscow, Russia; e-mail: [email protected] 2Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611, U.S.A. *Author for correspondence

Abstract

Recent molecular studies revealed the polyphyletic nature of the broadly defined genus Polygonum. This paper includes a standard maximum parsimony (MP) and three-taxon statement analyses (3TA) as well as a taxonomic revision of Polygonum sect. Avicularia subsect. Spinescentia (Polygonaceae) as compared with two closely related taxa: genus Atraphaxis s.s., and genus Bactria. In total, 27 characters, including life history, habit, morphology of the shoots, leaf blades, ocreas, perianth, achene, ultrasculpture of perianth and achene surfaces, as well as pollen morphology, were analyzed, illustrated, and dis- cussed in detail. Both the standard MP and 3TA confirm that monophyletic Polygonum subsect. Spinescentia is sister to the narrowly defined Atraphaxis. The genus Persepolium (Polygonum subsect. Spinescentia), with the circumscription of five species, is established as new to science as a result of this study. Possible transformations of perianth and thyrse morphology are discussed within the framework of the Principle of variable proportions by Troll in connection with a shift of pollination mode in the group of taxa studied.

Key words: Standard cladistic analysis, three-taxon statement analysis, taxonomy, achene surface sculpture, ocrea morphol- ogy, perianth morphology, pollen, sporoderm ornamentation, tepal micromorphology

Introduction

Recent molecular studies (Tavakkoli et al. 2015, Yurtseva et al. 2016a) have revealed the polyphyletic nature of the broadly defined genus Polygonum Linnaeus (1753: 359). This paper includes a standard Maximum Parsimony (MP) and Three-taxon statement analyses (3TA), as well as a taxonomic revision of Polygonum sect. Avicularia subsection Spinescentia (Polygonaceae) as compared with two closely related taxa: Atraphaxis Linnaeus (1753: 333), and Bactria Yurtseva & Mavrodiev (Yurtseva et al. 2016a: 42). Polygonum section Avicularia subsection Spinescentia Boissier (1879: 1027) comprises several endemics of West and South Iran: P. aridum Boiss. & Hausskn. in Boissier (1879: 1042), P. dumosum Boissier (1846: 83), P. khajeh-jamalii Khosravi & Poormahdi (2008: 477), P. salicornioides Jaubert & Spach (1844–46: tab. 123), and P. spinosum Gross (1913: 340). They are all erect dwarf caespitose undershrubs, or shrubs with abandantly branched shortly puberulent annual shoots, linear-elliptical or oblong-lanceolate leaf blades, short bifid truncate-tubular ocreas, terminal thyrses of several cymes of 1–2 (3) flowers, a campanulate or urceolate perianth with equal-sized segments, which is totally densely minutely puberulent outside. Recent molecular phylogenetic analyses (Tavakkoli et al. 2015) discovered the sister position of Polygonum subsection Spinescentia to Atraphaxis, as well as the sister relationship of the clade (P. subsection Spinescentia plus Atraphaxis) and A. ovczinnikovii (Czukavina 1962: 62) Yurtseva (Yurtseva et al. 2014: 763). As a result, Tavakkoli et al. (2015) transferred Polygonum section Avicularia subsect. Spinescentia and Atraphaxis section Ovczinnikovia Yurtseva ex Tavakkoli (Tavakkoli et al. 2015: 1167) into the genus Atraphaxis, treating this taxon with a broad circumscription, perhaps broader than has ever been done before. According to Tavakkoli et al. (2015), Polygonum subsection Spinescentia is treated as Atraphaxis section Polygonoides S.Tavakkoli, Kaz.Osaloo & Mozaff. in Tavakkoli et al. (2015: 1167).

Accepted by Alexander Sennikov: 16 Jun. 2017; published: 25 Jul. 2017 151 Tavakkoli et al. (2015) also mentioned that aside from the five listed species of Polygonum, A. section Polygonoides should also include Polygonum botuliforme Mozaffarian (1988: 62), which is a rare and poorly known species from Central Iran. Both Tavakkoli et al. (2015) and Yurtseva et al. (2016a, b) reported conflicting positions for P. botuliforme in plastid vs. ITS-based topologies. As already mentioned (Yurtseva et al. 2016a, b), this issue requires further reappraisal and, at the moment, P. botuliforme is excluded from consideration here. Our results using Maximum Likelihood (ML) and Bayesian analyses (BI) based on ITS nrDNA regions as well as combined plastid regions (trnL (UAA) intron, trnL-F IGS, and rpl32-trnL (UAG) IGS) of Atraphaxis s.s. and related taxa showed that the name “A. ovczinnikovii” matches two taxonomic entities accepted at the specific rank (Yurtseva et al. 2016a). We also found that these two species form a strongly supported sister clade of (Polygonum subsection Spinescentia plus Atraphaxis s.s.) (combined plastid regions), that, however, appear paraphyletic on the phylogenetic trees based on ITS nrDNA regions. Both species are dwarf shrubs resembling some shrubby species of Polygonum by the campanulate perianth with five equal-sized segments, but have remarkable papillae at the segment margins and distinct sporoderm ornamentation. The genus Bactria (Yurtseva et al. 2016a: 42) has been proposed, which includes these two dwarf shrubs: B. ovczinnikovii (Czukav.) Yurtseva & Mavrodiev (Yurtseva et al. 2016a: 43) from Pamir and B. lazkovii Yurtseva & Mavrodiev (Yurtseva et al. 2016a: 43) from Tian-Shan. Our results using ML and BI based on ITS nrDNA regions and combined plastid regions confirmed Polygonum subsection Spinescentia as a strongly supported sister to Atraphaxis s.s. (Yurtseva et al. 2016a). However, we suggest that the proposed circumscription of Atraphaxis including Polygonum subsection Spinescentia (Tavakkoli et al. 2015) is questionable from a morphological standpoint due to the loss of morphological identity of Atraphaxis so circumscribed. The majority of species in the narrowly defined Atraphaxis (Yurtseva et al. 2016a) are shrubs or undershrubs with a rather specialized perianth characterized by accrescent inner segments and a long filiform tube. Several rare endemics from Central Asia differ in their perianth with equal-sized segments, but correspond to Atraphaxis s.s. in many other features (Yurtseva et al. 2010, Yurtseva et al. 2012a, b, 2016a, b, Schuster et al. 2011b). Atraphaxis toktogulica (Lazkov) T.M.Schust. & Reveal, A. atraphaxiformis (Botsch.) T.M.Schust. & Reveal, A. ariana (Grigorj.) T.M.Schust. & Reveal (Schuster et al. 2011b: 1663), and A. tortuosa Losinsk. (Losina-Losinskaja 1927: 44) are nested individually within the clade Atraphaxis in plastid and ITS-based phylogenetic trees (Yurtseva et al. 2016a, b) and are particularly important for comparison with the members of Polygonum subsection Spinescentia when investigating convergent features in these sister groups. A comprehensive comparative morphological analysis of Polygonum subsection Spinescentia and closely related Atraphaxis s.s., as well as of the recently described genus Bactria, is the main goal of this study. This analysis is critical in order to evaluate the results of the previous molecular phylogenetic analyses of the complex, as well as to clarify the rank of Polygonum subsection Spinescentia.

Materials & Methods

Data sources The morphological study involved eight type and verified specimens of Polygonum aridum, P. dumosum, P. salicornioides, and P. spinosum from P. subsection Spinescentia, and more than 400 specimens of 15 species of Atraphaxis representing all its sections and morphological groups, as well as five specimens of Bactria ovczinnikovii, and the holotype of B. lazkovii. The specimens are stored in the Herbaria of V.L. Komarov Botanical Institute RAS, St. Petersburg, Russia (LE); Botanical Department of St. Petersburg University, St. Petersburg, Russia (LECB); M.V. Lomonosov Moscow State University, Moscow, Russia (MW). High-resolution images of the type specimens of P. aridum, P. dumosum, P. salicornioides, and P. spinosum (B—http://ww2.bgbm.org/herbarium/, G-BOIS, LINN—http:// linnean-online.org/linnaean_herbarium.html, M, and P—https://science.mnhn.fr/taxon/genus), were also carefully examined. All of the taxa included in the morphological analysis are listed in Appendix 1. Additionally to the certain number of the herbarium specimens and images (summarized above), we studied and compared morphological characters of Atraphaxis and related taxa using the comprehensive observations from the literature. For Atraphaxis we used the data from Ronse De Craene & Akeroyd (1988), Ronse De Craene & Smets (1991), Hong (1995), Hong et al. (1998), Hong et al. (2005), Yurtseva et al. (2012a, 2014, 2016a, b). For Polygonum subsection Spinescentia, we used the data from Jaubert & Spach (1844–1846), Boissier (1846, 1879), Meisner (1857),

152 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. Gross (1913), Mozaffarian (2012), Khosravi & Poormahdi (2008), Tavakkoli et al. (2015), and Yurtseva et al. (2016a). Due to the complete lack of the available material of Polygonum khajeh-jamalii, the data from Khosravi & Poormahdi (2008) was obtained for the morphological analysis of this species. Bactria ovczinnikovii (Czukavina 1962, 1968, Yurtseva et al. 2016a), and B. lazkovii (Yurtseva et al. 2016a) were also included in the study.

Morphological analysis a. Scanning electron microscopy (SEM) and light microscopy (LM) Light microscopy (LM) images were made with the stereoscopic microscope Stemi 2000-C Carl Zeiss (Zeiss, Germany) using the camera Axiocam-MR and program AxioVision V. 4.8 free edition. For scanning electron microscopy (SEM) dry material and pollen were transferred onto aluminum stubs, coated with gold or alloy of platinum and palladium using a JFC-1100E sputter coater and studied under a scanning electronic microscope Camscan-S2 at 15–20 kV. SEM work was performed at the Electron Microscopy Laboratory of M. V. Lomonosov Moscow State University, Faculty of Biology. Pollen size measurements were conducted using samples acetolyzed according to Erdtman’s standard method (Erdtman 1971) and investigated with a stereoscopic light microscope Leica DME. The specimens of Atraphaxis, Bactria, and Polygonum subsection Spinescentia used in SEM and LM work are listed in Appendix 1. Perianth and achene surfaces were described using the terminology of Ronse De Craene & Akeroyd (1988), Ronse De Craene et al. (2000), and Barthlott (1981, 1984). Pollen morphology was described as suggested by Punt et al. (2007) and Hesse et al. (2009). b. Coding of characters, standard maximum parsimony and three-taxon statement analyses The actual outgroup taxon of the broadly circumscribed genus Atraphaxis (incl. Bactria and Polygonum subsection Spinescentia) (Tavakkoli et al. 2015) remains unknown. As summarized above, the results of molecular phylogenetic analyses (ML and BI) of the tribe Polygoneae (Tavakkoli et al. 2015; Yurtseva et al. 2016a) showed Bactria as immediate sister of the clade Polygonum subsection Spinescentia plus Atraphaxis s.s. However, this genus is circumscribed to include two geographically distinct taxa: B. ovczinnikovii and B. lazkovii that are not completely identical from a morphological standpoint (Yurtseva et al. 2016a). Thus, due to some morphological heterogeneity of Bactria, an artificial, all-plesiomorphic taxon (reviewed in Kitching et al. 1998) was used as an outgroup for the standard MP analysis, assuming that the morphology of B. lazkovii was almost equivalent to this artificial all-zero entity. In total, 27 characters (Appendix 2) including life history, habit, morphology of the shoots, leaf blades, ocreas, perianth, achenes, and pollen were analyzed and imaged (Figs. 1–18). Tables 1–3 summarize these comparisons. All of the characters (Appendices 2 and 3) were polarized a priori (character state “zero” was a priori assumed to be plesiomorphic) and have been treated as unordered (non-additive) (reviewed in Kitching et al. 1998). In addition to the standard MP analysis we used the three-taxon statement approach (3TA) to analyze the data. 3TA is another conceptualization of Hennigian cladistics, which was originally established by Nelson & Platnick (1991). 3TA is different from the standard MP analysis in numerous aspects (Nelson & Platnick 1991; Williams & Siebert 2000; Williams & Ebach 2008). Particularly, this method does not deal with the standard taxon-characters matrix, but with a set of minimal relations of two taxa relative to a third one (the three-taxon statements), written in the form of the taxon-character matrix (e.g., Nelson & Platnick 1991; Williams & Siebert 2000, Williams & Ebach 2008). As originally outlined (Nelson & Platnick 1991), 3TA requires a “permutation” of the standard taxon-character matrix to convert it to a three-taxon statement matrix that can be used as input for a phylogenetic computer program, such as PAUP* (Swofford 2002). Williams & Siebert (2000) were the first authors to delimit three-taxon statement representation of unordered (non- additive) multistate characters (reviewed in Kitching et al. 1998), and we follow their approach, as implemented in TAXODIUM v. 1.2 (Mavrodiev & Madorsky 2012). Using this software, the three-taxon statement (3TS) permutations were performed with the following command: taxodium input_file_name.csv –ium –ob –og –nex. Because 3TA is essentially a comparative method that completely avoids the optimisation of character-states (e. g., Williams & Siebert 2000), the meaning of the “all-zero outgroup” within the framework of 3TA is different when compared to the standard parsimony approach. Technically, all-zero outgroup has to be implemented into the 3TS matrix as an additional “taxon” (e.g., Nelson & Platnick 1991; Williams & Siebert 2000). But this is an operational entity that is used for future comparisons, not an actual taxon (real or hypothetical), as used in the standard approach. Therefore in 3TA, the value of the operational outgroup can be fixed as a value of a particular taxon from the matrix

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 153 (Williams & Siebert 2000). As explained above, in the case of standard MP analysis, the morphology of Bactria lazkovii yields the formulation of the artificial all-zero taxon. Therefore, for consistency with the standard MP analysis, in the case of 3TA, the value of the operational outgroup was also fixed as the value of Bactria lazkovii. All MP analyses were conducted with PAUP* 4.0a150 (Swofford 2002) using either conventional matrices or TAXODIUM’s output 3TS NEXUS files with a heuristic search of 1000 random addition replicates (saving no more than 100 trees per replicate), and with the TBR branch swapping/MulTrees option in effect. Branches with a minimum length of zero were collapsed. The bootstrap resampling of both conventional and 3TS (2500 replicates) matrices was performed as described in Mavrodiev & Madorsky (2012). Using the topology that resulted from the standard MP analysis, selected morphological traits were optimized in the most parsimonious way (Figs. 19–21), as implemented in Mesquite v. 3.02 (Maddison & Maddison 2011).

Results

The morphological traits of Polygonum subsection Spinescentia, Bactria and Atraphaxis s.s. are summarized in Tables 1–3. a. Life history The members of Polygonum subsection Spinescentia demonstrate a strong similarity in the habit, structure of vegetative organs, and inflorescences. Polygonum aridum, P. dumosum, and P. salicornioides are caespitose dwarf undershrubs 10–25(30) cm tall. A many-headed caudex bearing vegetative buds is covered with dark-brown or grayish-brown fibrously disintegrating bark. A specific habit of these chamaephytes results from annual shoots abandantly branched from the base and leafless in summer (Fig. 1A–C, F–K). The annual shoots are 10–25 cm long, 1.0–1.5 mm in diameter, much branched, terete, wiry, rigid, erect or ascending, straight or slightly geniculate. The shoots and leaf blades are densely shortly puberulent, the leaf blades are somewhat fleshy, but usually early deciduous at onset of drought. The annual shoots die back for most part of their length, the lignified basal parts are 4–5 mm in diameter. Polygonum salicornioides differs by having somewhat fleshy, finely ribbed annual shoots with slightly inflated internodes (Fig. 1A–C). Polygonum spinosum is a dwarf shrub with lignified straight or slightly curved spiny shoots, so it is almost a thorn-cushion plant (Fig. 1D–E). In all of the species, the annual shoots are glaucous, densely velutinous-puberulent with short trichomes covering also the leaf blades, the bases of ocreas and articulations. The distinctive caespitose habit of Polygonum subsection Spinescentia well differentiates this group from both Bactria and Atraphaxis. Bactria are mesoxerophytic dwarf shrubs 10–20(50) cm tall with stout divaricately branched lignified shoots covered with gray or brown bark, the shoots are never spiny, annual shoots are leafy throughout the season. Atraphaxis are dwarf or tall mesoxerophytic shrubs (rarely undershrubs) 30–150 cm tall with stout lignified shoots covered with gray or brown bark, and annual shoots leafy for all the season. Thus, the external shape and the life history of Polygonum subsection Spinescentia, Atraphaxis and Bactria clearly differentiate these taxa from each other. b. Inflorescences In all of the species of Polygonum subsection Spinescentia the cymes of flowers appear in the axils of the developed leaf blades, which slightly reduce their size to the top of the annual shoots, forming terminal frondose or frondulose thyrses with 10–20 well spaced cymes of 1(2–3) flowers (Fig. 1). The internodes of annual shoots gradually reduce their length to the top from 15–20 at the low nodes to 4–5 mm at the upper nodes. Because of the frondose thyrses, in their habit the members of Polygonum subsection Spinescentia resemble some species of Polygonum, but not those of Atraphaxis. Plants of Polygonum subsection Spinescentia start anthesis in April–May, forming axillary cymes from the lower nodes of the shoots to the top (Fig. 1) and stop flowering by the onset of drought. Young flowers have short pedicels 0.5–1.0 mm hidden in ocreolas and upright (Fig. 2I). Mature flowers are erect at pedicels 0.5–1.0 mm long (P. aridum, P. spinosum), or hang down (P. dumosum, P. salicornioides) from bent, sturdy pedicels 1.5–2 mm long (Fig. 1B, G–K).

154 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. Figure. 1. Life history and shoots of Polygonum subsection Spinescentia: (A–C)—P. salicornioides, a dwarf undershrub with fleashy annual shoots (Kotschy 468, LE). (D–E)—P. spinosum, a dwarf shrub with lignified prickly shoots (Bornmüller 5083, LE). (F–G)—P. dumosum, a dwarf undershrub with wiry leafy annual shoots (Kotschy 242, LE). (H)—ibid (Wendelbo 790, LE). (I–J)—P. aridum, a dwarf shrub with wiry leafless annual shoots (Kuh-Enhker, Haussknecht s.n. LE). (K)—ibid (Sawers, Haussknecht s.n. LE). Images: O. Yurtseva.

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 155 Figure 2. Leaf blades (A–C, G–H) and ocreas (D–F, I) of Polygonum subsection Spinescentia: (A–D)—P. salicornioides, Kotschy 468, LE. (E–F)—P. dumosum, Kotschy 242, LE. (G–I)—ibid, Wendelbo 790, LE. Scale bar = 1 mm. Images: O. Yurtseva.

Bactria species have terminal frondulose thyrses with 3–7 axillary cymes of 1–2 flowers at short pedicels 0.5–1.0 mm hidden in ocreolas (more in Yurtseva et al. 2016a). The majority of Atraphaxis species have terminal bracteose thyrses (or racemes of thyrses) with 10–20 congested cymes of 2–6 flowers. The members of A. section Atraphaxis and A. sect. Physopyrum (Popov 1935: 23) Lovelius (1979: 127) differ in having short terminal and lateral thyrses with 2–6 congested cymes of 1(2) flowers. The flowers are exhibited from the cymes at long straight pedicels 3–6 mm long, which continue the filiform basal parts of perianth tubes. Mature flowers are pendulous and hang down from filiform pedicels (more in Yurtseva et al. 2016a). c. Leaf blades The leaf blades of Polygonum subsection Spinescentia are usually linear-lanceolate or oblong-elliptical, with an obtuse

156 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. or shortly acuminate apex, a base gradually narrowed towards the point of articulation with a wide triangular pulvilla, almost sessile, somewhat fleshy, flat or slightly revolute at the margin, with a midvein hardly visible adaxially, but prominent and keeled abaxially, and minutely puberulent on both sides. Leaf blades gradually reduce their size from the basal nodes to the upper nodes, so the extreme values of the length and width are given in Table 1.

Table 1. Selected morphological characteristics of Polygonum subsect. Spinescentia (*—by Khosravi & Poormahdi 2008) Morphological traits P. salicornioides P. dumosum P. aridum P. spinosum P. khajeh- jamalii* Leaf size at low nodes, 4–10 × 1.5–2.0 10–13 × 1–3 2–5 × 1–2 10–12 × 2–3 5–15 × 2–9 mm Leaf size at upper nodes, 4 × 1 3–5 × 1.0–1.5 2 3–5 × 1–2 3–10 × 1–3 mm Leaf blade shape elliptical or linear- oblong-elliptical linear-lanceolate linear-lanceolate ovate, lanceolate elliptical or linear- or linear-elliptical to linear- lanceolate lanceolate Leaf consistence fleshy fleshy fleshy fleshy coriaceous Ocrea size at low nodes, 4 6–7(10) 3.2–3.5(5) 3–5 3–4 mm Ocreola size at upper 1–2 3–4 1–1.5 2.5–4.0 2–3 nodes, mm Ocrea shape truncate-tubular truncate-tubular truncate-tubular acute-tubular acute-tubular Number of veins in ocrea 2 0–2 4–6 0 ? Perianth shape urceolate urceolate or widely campanulate campanulate campanulate campanulate Perianth length, mm 3.0–5.0 (6.0–6.5 in 2.5–5.5 2.5–5.0 3.0–4.0 2.0–3.0 fruiting) Tepal size, mm 2.8–3.0 × 1.1–1.5 2.0–2.5 × 1.0–1.5 2.0 × 1.5 2.5 × 1.5–2.0 2–5 × 1.5–2.0 Tepal shape oblong-elliptical to oblong-ovate to oblong-ovate oblong-ovate ovate oblong-spatulate oblong-elliptical Tube length, mm 1.5–1.6 2.0 1.5–2.0 1.3–1.6 ? Tube filiform base length, 0.3 0.3–0.5 0.2–0.3 0.1–0.2 ? mm Pedicel length, mm 1.5–2.0 2.0 1.0–1.5 1.5–2.0 ? Trichomes on perianth 30–60 25–35 17–30 20–30 ? length, µm Achene size, mm 3.5–4.0 × 2.8–3.4 ? 4.5–5.0 ×2.5–3.2 4.5–5.0 ×2.5–3.2 4.5–5.0 ×2.5–3.2

Polygonum salicornioides has elliptical or linear-elliptical leaf blades with an obtuse or shortly acuminate apex (Figs. 2A–C; 3S). Polygonum dumosum has oblong-elliptical to linear lanceolate leaf blades, often with two longitudinal ridges at both sides of a midvein on the adaxial side (Figs. 2G–H; 3A, C–D, F). At the upper nodes the leaf blades are strongly reduced (Fig. 3G, I), or transformed into small tongue-like outgrowths 2–3 mm long with two stipule-like lateral lacinulas, all covered with long ciliated hairs (Fig. 3K). Polygonum aridum has the smallest linear leaf blades, the upper ones also representing tongue-like outgrowths covered with ciliated hairs (Fig. 3O). Polygonum spinosum has linear-lanceolate or linear-elliptical leaf blades with acute or subulate apex, rigid, leathery, with a prominent midvein on the abaxial side (Fig. 3X–Y). The leaf blades of all of these species are densely covered with linear trichomes 50–90 µm long and 9–12 µm in diameter on both sides (Fig. 8A–B). Bactria and Atraphaxis have clearly petiolate, thick, leathery leaf blades preserved for all the season. The leaf blades vary in shape and size.

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 157 Figure 3. Ocreas and ocreolas of Polygonum subsection Spinescentia: (A–K)—P. dumosum, Kotschy 242, LE: (A–F)—ocreas (A– B, E–F) and lead blades (A, C–F) of vegetative part of shoot, (G-K)—ocreolas and reduced leaf blades. (L–M)—P. aridum, Sawers, Haussknecht s.n. LE: (L–M)—ocreas, (N–O)—ocreolas. (P–W)—P. salicornioides, Kotschy 468, LE: (P–S)—ocreas and a leaf blade of vegetative part of shoot, (T–W)—ocreolas. (X–Y)—P. spinosum, Bornmüller 5083, LE, leaf blades and ocreas of vegetative shoot. Scale bar = 1 mm. Images: O. Yurtseva.

158 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. Bactria has broadly ovate, oblong-elliptical or lanceolate leaf blades, shortly acuminate, narrowed to a petiole 1–2 mm long, slightly undulate and revolute at the margin, leathery, almost glabrous or minutely puberulent (more in Yurtseva et al. 2016a). The leaf blades of Atraphaxis s.s. vary in shape from rotund, broadly ovate, broadly elliptical to spatulate, oblong- elliptical and linear-lanceolate, suddenly narrowed into a petiole 2–5 mm long jointed with articulation, flat, slightly revolute, finely crenulate or undulate at the margin, glabrous or shortly papillate at the edge (more in Yurtseva et al. 2016a). d. Ocreas and ocreolas Polygonum subsection Spinescentia, Bactria and Atraphaxis have some differences in the ocrea morphology. The ocreas of Polygonum subsection Spinescentia are truncate-tubular, or acuminate-tubular, 3–10 mm long, membranous, whitish-transparent, glabrous, either without veins (P. spinosum), with two veins (P. dumosum, P. salicornioides), or 4–6 veins (P. aridum) (Figs. 2, 3). The ocreas gradually reduce their size from the basal nodes towards the upper nodes, so the extreme values of the length are given in Table 1. At the basal nodes the ocreas are equal to or shorter than the internodes. They are acuminate or truncate at the side opposite to the leaf blade, later bidentate or dentate-incised (Fig. 3A–B, E–F, G, H, L–M, P–R, X–Y). At both sides of the leaf blade the ocreas are split to the base in two lanceolate lacinulas, each with a single vein (Figs. 2E–F; 3A, I, L, Q–R). At the upper fertile nodes the ocreolas are 1–4 mm long, truncate-tubular (Figs. 2D, H–J, M–O, T–W), rarely acuminate-tubular (Fig. 3G, X–Y), at maturity bilacerate, bidentate (Fig. 3I, J, M–O, T), dentate-incised, or fimbriate-lacerate (Figs. 2D, 3N–O, T–W).

Figure 4. Ocreas of Bactria and Atraphaxis: (A–C)—B. ovczinnikovii, Ukrainskaya et al. 12, MW. (D–F)—A. virgata, Gubanov 7227, MW. (G–H)—A. ariana, Gorelova s.n. LE. (I–J)—A. toktogulica, Ajdarova et al. s.n. LE. (K–M)—A. seravschanica, Boryaev & Gubanov 43, LE. Scale bar = 1 mm. Images: O. Yurtseva.

The ocreas and ocreolas of Polygonum subsection Spinescentia differ from those of Polygonum, which are lanceolate-tubular, 4–10 mm long, with 7–11 veins, later fimbriate-lacerate. Bactria has shorter, broadly ovate or lanceolate-tubular ocreas 2–4 mm long, herbaceous and densely shortly puberulent at the base, membranous, semitransparent, bidentate above, without veins or with two hardly visible veins (Fig. 4A–C), at maturity deeply split in two lanceolate lacinulas. In thyrses, the ocreolas are 2–4 mm long, broadly ovate, inflated at the base, later bidentate or bilacerate (more in Yurtseva et al. 2016a).

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 159 Figure 5. Perianths of Polygonum subsection Spinescentia: (A–C)—P. salicornioides (Kotschy 468, LE), perianth outside (A), inside (B), and segment outside (C). (D)—P. spinosum (Bornmüller 5083, LE). (E)—P. dumosum (Kotschy 242, LE); (F)—ibid, (Wendelbo 790, LE). (G–I)—P. aridum (Sawers, Haussknecht s.n. LE): mature flower (G); achene exserted from the perianth (H); young flower (I). Scale bar = 0.1 mm for C; = 0.2 mm for F, H; =0.5 mm for I; = 1 mm for the rest. Images: O. Yurtseva.

Atraphaxis has oblique-tubular ocreas 3–10 mm long (Fig. 4D–M), herbaceous, glabrous or minutely papillate at the base, membranous, transparent, glabrous above, with two veins. At maturity, the ocreas are split to the base, so that two subulate-aristate lacinulas, each with a single vein, are connected by a truncate, entire or serrate-incised middle portion, which is opposite to the leaf blade. In thyrses, the ocreolas are 2–7 mm long, oblique funnel-form, membranous, with a small acute herbaceous or transparent keel, later lacerate. e. Perianth morphology The members of Polygonum subsection Spinescentia have urceolate or campanulate perianths 2.5–6.5 mm long divided to 2/3–3/4 of its length in five equal-sized segments. The funnel-form tube 1.3–2.0 mm long includes a filiform basal part 0.1–0.3(0.5) mm long, which is jointed to a pedicel 1–2 mm long (Table 1). The segments are oblong-elliptical, oblong-ovate or oblong-spatulate, with an obtuse or acuminate apex (Figs. 5A–B, D–E, G–I; 6A). The two outer segments are slightly keeled and cucullate, the three inner segments are almost flat. All the segments are leathery, purplish-green, with extremely narrow pinkish membranous margins. The perianths are more or less densely minutely

160 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. puberulent outside (Figs. 5C, F; 7A–F; 8C–F, H–K), glabrous inside (Fig. 7G–I), with papillae inserted in the tepal margins (Fig. 7A–C, K–L). The achenes are fully enclosed (P. spinosum, P. salicornioides), or slightly exserted from the perianths (P. dumosum, P. aridum) (Fig. 5A, E, G–H).

Figure 6. Perianths of Polygonum salicornioides (A), Bactria ovczinnikovii (B–C), Atraphaxis toktogulica (D–F), Atraphaxis virgata (D) and A. frutescens (H–I). Scale bar = 1 mm. Images: O. Yurtseva.

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 161 Bactria has a campanulate perianth deeply divided (to 4/5–5/6 in B. lazkovii, to 5/6–8/10 in B. ovczinnikovii) in 5(6) equal-sized segments, with a short tube 0.5–0.8 mm long including an extremely short (0.1–0.2 mm), filiform basal part (Fig. 6B–C, Table 2). Atraphaxis toktogulica, A. atraphaxiformis, A. tortuosa, and A. ariana have campanulate perianths 5–6 mm long divided to 2/3–3/4 in five equal-sized petaloid segments 2.5–3.5 × 1.3–2.5 mm, with a funnel-form perianth tube 1.0–2.5 mm long, including a filiform basal part 0.5–1.0 mm long (Fig. 6D–F, Table 2).

Table 2. Morphology of Bactria ovczinnikovii, Polygonum subsect. Spinescentia, and Atraphaxis s.s. Characters Bactria ovczinnikovii Polygonum subsection Atraphaxis species with Atraphaxis species with Spinescentia equal-sized segments unequal segments Life history divaricately branched basitonically branched dwarf or tall shrubs or dwarf or tall shrubs, rarely dwarf stout shrub caespitose dwarf shrubs undershrubs undershrubs or undershrubs Height, cm 10–30 10–15 30–60 30–150 Annual shoots elongated, stout elongated, wiry elongated, stout elongated and constricted, stout Surface of annual shortly velutinous- shortly velutinous- shortly velutinous- papilloso-puberulent or shoot puberulent puberulent puberulent glabrous Shape of leaf blade broadly ovate to linear-elliptical, linear- rotundate, broadly rotundate, broadly ovate, rhomboid-elliptical lanceolate, ovate, ovate, elliptical, linear- elliptical, linear-lanceolate oblong-lanceolate lanceolate Leaf margin slightly revolute slightly revolute flat or slightly revolute, flat or slightly revolute, finely crenulate, or finely crenulate, or undulate undulate Ocrea length at 2–4 3–10 7–10 3–7 vegetative shoots, mm Ocrea shape at lanceolate-tubular, lanceolate-tubular or tubular, with two linear- tubular, with two linear- vegetative shoots later bilacerate, truncate-tubular, later lanceolate lacinulas and lanceolate lacinulas and without veins bilacerate or bidentate, serrate-incised middle serrate-incised middle part with 0–6 veins part Ocreola in thyrses, oblique-tubular lanceolate-tubular or oblique funnel-form, oblique funnel-form, with shape and length, inflated under the truncate-tubular, with reduced leaf blade reduced leaf blade or a mm petiole, 4–5 1–4 or a keel, 2–7 keel, 2–7

Position of thyrses terminal terminal terminal terminal or lateral Thyrses frondulose frondose, frondulose bracteose bracteose Number of cymes in 5–6 10–20 6–20 6–20 thyrses Perianth shape in campanulate, with campanulate or campanulate with equal- accrescent inner segments fruiting equal-sized segments urceolate, with sized segments enclosing enclosing the achene, not enclosing the equal-sized segments the achene spread or reflected outer achene enclosing the achene segments or not Perianth length in 4.0–5.0 4.0–6.5 3.0–6.5 6.5–14.5 fruiting stage, mm Perianth partition 5/6–8/10 2/3–¾ 2/3–¾ ½–3/4 (9/10 in A. teretifolia) Segment size equal equal equal subequal or unequal ...continued on next page

162 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. TABLE 2. (Continued) Characters Bactria ovczinnikovii Polygonum subsection Atraphaxis species with Atraphaxis species with Spinescentia equal-sized segments unequal segments Segment shape lanceolate, outer oblong-elliptical, oblong-elliptical, oblong- rotundate, reniform, slightly acuminate oblong-ovate, ovate, or obtuse, flat or broadly elliptical, broadly and cucullate, inner acuminate, outer cucullate ovate, obtuse, flat, obtuse, flat concave, keeled, undulate, rarely concave cucullate, inner almost flat Inner/outer segment 1 1 1 1/2–1/4 ratio Shape of perianth cup-form funnel-form funnel-form filiform, with wedge- tube shaped or cup-shaped extension at the top

Tube length, mm 0.5–0.8 1.3–2.0 1.0–2.5 1.5–7.5 (0.5 in A. teretifolia) Length of filiform 0.1–0.2 0.1–0.3(0.5) 0.5–1.0 1.0–7.0 (0.5 in A. part of tube, mm teretifolia) Papillae at perianth — 17–60 × 5–8 (12) 30–50 × 20–35 — tube Papillae at segment present present present or absent absent edge Surface of perianth glabrous shortly puberulent glabrous or rarely shortly glabrous segments papillate Stomata at segments present present present absent or rarely present at base Segment consistence leafy leafy petaloid petaloid Position of stamens inserted at the base of inserted at the middle inserted at the middle inserted at the edge of receptacle part of receptacle part of receptacle receptacle Sporoderm microreticulate- foveolate, striate-perforate, rarely striate-perforate ornamentation foveolate foveolate-perforate, reticulate-perforate (A. microreticulate- toktogulica) foveolate, striate- perforate Achene size 4.0–5.0 × 2.2–2.8 3.5–4.0 × 2.8–3.4 3.5–4.0 × 2.8–3.4 2.5–5.5 × 1.5–5.0 Achene shape ovoid, triquetrous ovoid, triquetrous ovoid, triquetrous, with ovoid, triquetrous or distinct ribs lenticular Achene surface smooth or smooth- minutely tuberculate minutely tuberculate smooth, smooth-pitted pitted Styles connate at base connate at base connate at base free, or connate at base Stigmas mini-capitate linear, inflated capitate fimbriate-capitate

The majority of Atraphaxis species have a more specialized perianth with accrescent inner segments 4.0–8.0 × 4.0–9.0 mm widely open in flowering and upright in fruiting, and two smaller outer segments spread or reflected to a pedicel. The tube 1.5–7.5 mm long has a filiform basal part 1.0–7.0 mm long, which includes a gynophore and is fused to the latter, and the expanded shallow upper part that includes an ovary (Fig. 6G–I, Table 2). Thus, Bactria, Polygonum subsection Spinescentia, and part of Atraphaxis share the campanulate or urceolate perianths, whereas the majority of Atraphaxis species have more specialized perianths.

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 163 f. Perianth surface The outer perianth epidermal cells of Polygonum salicornioides, P. spinosum, P. dumosum, and P. aridum are similar in shape and size (Figs. 7–8).

Figure 7. Perianth surface of Polygonum subsection Spinescentia (SEM): (A–I)—P. salicornioides (Kotschy 468, LE): papillate surface of perianth segments outside (A–D), perianth tube outside (E–F), and perianth segment inside (G–I). (J–L)—P. spinosum (Bornmüller 5083, LE): middle part of perianth segment outside (J), and papillate segment edge (K–L). Scale bar = 100 μm for A; = 300 μm for G; = 30 μm for B–D, H–L; =10 μm for E. Images: O.V.Yurtseva.

The tube and the bases of the segments are covered by 5–6-polygonal epidermal cells with straight anticlinal walls, flat or low-domed outer periclinal walls bearing a fine irregular cuticular striation (Figs. 7E–F, 8G). The cells of the segments are oblong-rectangular or irregular, with straight to slightly sinuate anticlinal walls, and have convex outer periclinal walls which bear a longitudinal or random cuticular striation (Figs. 7A–D, J–L; 8C–F, H–K). Stomata are scattered over the outside of perianth surface, being more abundant along midveins (Figs. 7J; 8H–I). Many of the epidermal cells form short linear trichomes with tightly pressed longitudinal cuticular striae radiating from the base

164 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. to the periphery of the cells (Fig. 7C–F; 8F, I–K). They are 5–8 (12) µm in diameter, 17–60 µm long (Table 1) and resemble the trichomes covering the leaf blades (Fig. 8A–B) and annual shoots. The trichomes are especially dense on the perianth of P. salicornioides (Fig. 7A–F), P. dumosum (Fig. 8C–F), rare in P. spinosum (Fig. 7J–L) and P. aridum (Fig. 8G–K), but are always inserted in the segment edges (Figs. 7A–C, K–L; 8J).

Figure 8. Leaf blade (A–B) and perianth (C–L) surface of Polygonum subsection Spinescentia (SEM): (A–F)—P. dumosum (Kotschy 242, LE): leaf blade abaxially (A–B); perianth segments outside (C–F). (G–L)—P. aridum (Sawers and Kuh-Enhker, Haussknecht s.n. LE): perianth tube outside (G); middle part of perianth segment outside (H–I); the edge of perianth segment outside (J–K); perianth segment inside (L). Scale bar = 300 μm for A; = 30 μm for B–K; = 10 μm for L. Images: O. Yurtseva.

The inner surface of the perianth segments is smooth, covered by oblong-rectangular or linear-rectangular epidermal cells with straight anticlinal walls and flat outer periclinal walls, the latter with prominent longitudinal cuticular striae (Figs. 7G–I). The epidermal cells covering the tepals adaxially become strongly sinuate in outline towards the top of the segments and have a fine random cuticular striation (Fig. 8L). They resemble the epidermis covering both sides of petaloid segments of Atraphaxis (Figs. 10G, I; 11B, F, K; 12E–F).

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 165 Figure 9. Abaxial perianth surface of Bactria and Atraphaxis (SEM). (A–B)—B. ovczinnikovii, the outer segment with papillae at the edge. (C–D)—A. atraphaxiformis: perianth tube (C), papillae at segment edge (D). (E–I)—A. tortuosa: polygonal cells of perianth tube (E–F), perianth segment outside (G–H), and inside (I). (J–L)—A. toktogulica: perianth tube of flower bud (J), conical papillae at tube of mature flower (K) and flowerbud (L). Scale bar = 100 μm for A, E; = 30 μm for B–D, G, I–L; = 10 μm for F, H. Images: O. Yurtseva.

In Bactria, the epidermal cells of the tepals are elongate-rectangular (B. ovczinnikovii, Fig. 9A–B), or sinuate in outline (B. lazkovii), with flat or low-domed outer periclinal walls bearing a random cuticular striation. The tube is covered by rectangular or 5–6-gonal epidermal cells with straight anticlinal walls and dome-shaped outer periclinal walls with a deep irregular or longitudinal cuticular striation. Stomata are randomly scattered across the tube and the tepals along the midveins, but are absent from the segment margins. The perianth is glabrous, but the papillae with tightly pressed longitudinal striations are inserted in the segment edges (Fig. 9A; Table 2). Atraphaxis toktogulica, A. atraphaxiformis, A. tortuosa, and A. ariana have perianth tubes covered by oblong or 5–6-gonal epidermal cells (Figs. 9C, E–F, J; 10B). The segments are covered by oblong-rectangular or irregular cells, slightly sinuate in outline (Figs. 9D, G–I; 10A, C–D). Conical papillae 30–50 µm long, 20–35 µm in diameter cover the outside of the tube and the segment bases (Fig. 9K–L; 10B). These papillae are as long as the linear trichomes covering the perianth of Polygonum subsection Spinescentia, but are twice as wide and have a finer, tightly pressed cuticular

166 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. striation. Similar papillae are inserted in the segment margins of A. atraphaxiformis, A. toktogulica (Figs. 9D; 10A), some specimens of A. tortuosa (Fig. 9G, I), but not of A. ariana, which has smooth segment edges (Fig. 10C). The majority of Atraphaxis species have a more specialized perianth. The epidermal cells covering the expanded upper part of the tube are 5–6-gonal, rectangular or irregular, with straight anticlinal walls, and dome-shaped outer periclinal walls with a deep irregular cuticular striation (Figs. 10J–K; 11A, C, E, J; 12A–B, D, G). Rare thin-walled papillae are present on the tube of A. badghysi Kultiasov (1923: 118) and A. aucheri Jaubert & Spach (1844–1846: tab. 114) (Fig. 10E–F), but the tubes of other species are glabrous.

Figure 10. Abaxial perianth surface of Atraphaxis (SEM): (A)—A. toktogulica, papillae at segment edge. (B)—A. ariana, dome- shaped cells of perianth tube, some forming papillae. (C)—A. ariana, segment edge. (D)—A. ariana, epidermal cells of petaloid segment. (E–F)—A. badghysi, dome-shaped cells of perianth tube, some forming papillae. (G)—A. badghysi, sinuate epidermal cells of segment, flower bud. (H–I)—A. aucheri, oblong epidermal cells of segment, flower bud. (J–L)—A. virgata, polygonal cells of perianth tube (J–K) and oblong cells of segment edge (L), flower bud. Scale bar =30 μm for A, C, J; = 10 μm for B, D, F–I, K–L; = 50 μm for E. Images: O. Yurtseva.

The epidermal cells covering the segments of flower buds and young flowers are oblong-rectangular, with straight or slightly sinuate anticlinal walls, dome-shaped outer periclinal walls, which have a prominent, random, transverse or

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 167 longitudinal cuticular striation (Fig. 10G–I, L; 11B, F, K, L; 12E, F, H). In mature flowers, the epidermal cells of the segments become two or three times larger, sinuate in outline, with flat or concave outer periclinal walls, bearing weak and fine, random cuticular striations (Figs. 11D, G–I; 12C, I). Thus, the tepals of Polygonum subsection Spinescentia and Bactria ovczinnikovii have the micromorphology common for sepals, while the tepals of Bactria lazkovii and Atraphaxis have the micromorphology usual for petals.

Figure 11. Abaxial perianth surface of Atraphaxis (SEM): (A–B)—A. manshurica, polygonal cells of tube (A) and oblong cells of segment (B), young flower. (C–D)—A. avenia, polygonal dome-shaped cells of tube (C) and oblong cells of segment (D), young flower. (E–F)—A. seravschanica, polygonal dome-shaped cells of tube (E) and sinuate cells of segment (F), flower bud. (G)—A. caucasica, perianth segment of mature flower. (H)—A. muschketowi, segment of mature flower. (I) A. laetevirens, segment of mature flower. (J–L)— A. billardierei, polygonal dome-shaped cells of tube (J), sinuate cells of segment (K–L), flower bud. Scale bar = 30 μm for A–B, K–L; = 10 μm for C–J. Images: O. Yurtseva. g. Stamens and nectar-secreting zone The members of Polygonum subsection Spinescentia have eight stamens with the filaments flattened and gradually dilated to the bases, and ovate anthers (Figs. 5B; 6A; 13A, D, E). The filaments of the three inner stamens are 1.2 mm long, twice longer and 2–4 times wider at the base than the subulate-lanceolate filaments of the five outer stamens, and half the length of the perianth segments. The bases of all of the filaments are inserted towards the upper part of the

168 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. receptacle formed by the fused bases of the segments, and are adaxially fused to the receptacle. The filaments of the five outer stamens are inserted above the filaments of the three inner stamens. Most of the filament surface is covered with oblong-rectangular, almost linear epidermal cells with a finely reticulate, ridged or irregular cuticular striation (Fig. 13B, F, G). The bases of the filaments and the receptacle around the bases of the filaments are covered with smooth rounded epidermal cells, which might be a nectar-secreting tissue (Fig. 13C, H, I). The outer periclinal walls of these cells are convex and bear hemispherical bulges, which possibly contain the nectar, and small perforations. These cells are supposed to perform a secretion of nectar by diffusion through thin walls.

Figure 12. Abaxial perianth surface of Atraphaxis (SEM): (A)—A. tournefortii, polygonal dome-shaped cells of tube, flower bud. (B, D)—A. pungens, dome-shaped cells of tube, young flower. (C)—ibid, segment edge of mature flower. (E)—ibid, segment of flower bud. (F)—A. fischeri, segment of flower bud. (G–H)—A. frutescens, tube (G) and segment (H) of flower bud. (I)—A. teretifolia, segment edge. Scale bar = 30 μm for A, I; = 50 μm for B, C; = 10 μm (D–H). Images: O. Yurtseva.

Bactria ovczinnikovii has the perianth more deeply divided (to 5/6–8/10), and the filaments of all eight stamens inserted towards the base of the receptacle (Figs. 6B–C; 14A). The flattened filaments of the three inner stamens are strongly dilated for most part of the length, are two-three times wider and somewhat longer than the lanceolate- subulate filaments of the five outer stamens. The epidermal cells of the filaments resemble the adaxial epidermis of the segments: they are oblong-rectangular, with a fine and irregular cuticular striation (Fig. 14B). In B. lazkovii, the filaments of the three inner stamens bear papillae inserted laterally and resembling the papillae inserted in the segment edges. The receptacle zone around the bases of the filaments is covered with polygonal nectariferous epidermal cells with smooth outer periclinal walls (Fig. 14C). The species of Atraphaxis with equal-sized perianth segments (A. ariana, A. atraphaxiformis, A. toktogulica, and A. tortuosa) have similar morphology and position of the stamens, as compared to Polygonum subsection Spinescentia. The flattened filaments of the three inner stamens are strongly dilated at the bases and subulate at the tops (Figs. 6F; 14D, G, J). The filaments of the inner stamens are inserted towards the top of the receptacle lower than the filaments of the five outer stamens. Most part of the filament surface is covered with oblong-rectangular epidermal cells with a fine

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 169 cuticular striation (Fig. 14E, H, K). The bases of the filaments and the receptacle below and around them are covered with roundish or polygonal nectar-secreting cells. They have smooth and shiny outer periclinal walls with small pits or perforations (Fig. 14F, I, L).

Figure 13. Filaments (A, D, E), epidermis of the filaments (B, F, G), and nectar-secreating zone (C, H, I) of Polygonum subsection Spinescentia (SEM): (A–C)—P. salicornioides (Kotschy 468, LE). (D–I)—P. aridum (Sawers, Haussknecht s.n., LE). Scale bar = 300 μm for A, D–E; = 30 μm for B–C, F–I. Images: O. Yurtseva.

The majority of Atraphaxis species with accrescent inner perianth segments and a long tube have eight stamens with the subulate filaments, which are more or less flattened and dilated at the bases. The receptacle is extremely shallow, with the bases of the filaments inserted in its upper part (Figs. 6G, I; 15A, B). At anthesis, the perianth segments are directed outward, and the stamens and ovary are in upper position exibiting pollen and stigmas (Fig. 6I). The filament bases are lined adaxially with rectangular nectar-secreting cells with a smooth cuticle (Fig. 15B, E). The remainder of the filament surface is covered with oblong-rectangular epidermal cells with a fine cuticular striation (Fig. 15F). Atraphaxis fischeri Jaubert & Spach (1844–46: tab.110: 12) and A. spinosa Linnaeus (1753: 333) have thin-walled papillae at the dilated bases of the filaments adaxially and abaxially (Fig. 15B–D). h. Achene morphology and exocarp sculpture The achene morphology is extremely uniform in Polygoneae (Ronse De Craene et al. 2000) and the studied taxa are no exceptions. The members of Polygonum subsection Spinescentia have broadly ovoid trigonous achenes with distinct narrow ribs and equal concave faces (Table 1). Three styles extend the achene ribs and are partly fused at the base, their free segments are terminated with linear, slightly inflated stigmas (Fig. 15G, I). Polygonum aridum, P. dumosum, P. salicornioides, and P. spinosum have a minutely tuberculate achene surface with semi-spheroidal tubercules 15–20 µm in diameter randomly scattered across the achene faces and ribs (Figs. 5H; 15G, H). The exception is P. khajeh-jamalii with a smooth shiny achene surface (Khosravi & Poormahdi 2008). The tubercles at the achene surface are thin-walled

170 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. invaginations of the outer periclinal walls of exocarp cells, which might ease absorption of water (Ronse De Craene et al. 2000, Yurtseva 2001). Atraphaxis atraphaxiformis, A. toktogulica, and A. tortuosa have the achenes of similar shape and size, with a minutely tuberculate surface, which is smooth and glossy in A. ariana. Three styles extending the achene ribs are fused at the base and terminated with mini-capitate stigmas (Fig. 15J).

Figure 14. Filaments (A, D, G, J), epidermis of the filaments (B, E, H, K), and nectar-secreating zone (C, F, I, L) of Bactria and Atraphaxis (SEM): (A–C)—Bactria ovczinnikovii, Nepli s.n. LE. (D–F)—Atraphaxis toktogulica, Ajdarova et al. s.n. LE; (G–I)—A. atraphaxiformis, Kamelin 523, LE. (J–L)—A. ariana, Androsov s.n. LE. Scale bar = 300 μm for A, D, G, J; = 30 μm for the rest. Images: O. Yurtseva.

The species of Atraphaxis with accrescent inner perianth segments have smooth ovoid achenes, mostly trigonous (lenticular in A. section Atraphaxis), with obtuse or distinct ribs, concave faces, and three (rarely two) styles, free or partly fused at the base, terminated with large fimbriate-capitate stigmas (Fig. 15L; Table 2) (more in Yurtseva et al. 2016a).

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 171 Bactria ovczinnikovii has broadly ovoid trigonous achenes with smooth and shiny concave faces and distinct ribs (Table 2), three styles, which are fused at the base and terminated with mini-capitate stigmas (Fig. 15K). Bactria lazkovii has smaller achenes with flat shiny faces, obtuse ribs, and free styles (more in Yurtseva et al. 2016a).

Figure 15. Flowers and achenes of Atraphaxis (A–F, J, L), Bactria (K), and Polygonum subsection Spinescentia (G–I) (SEM): (A–B)—A. fischeri, filaments at the receptacle edge. (C–D)—ibid, papillae at the filament base. (E)—ibid, nectar-secreating zone of receptacle. (F)—A. pungens, epidermis of filament. (G)—Polygonum salicornioides, three linear styles connate at base. (H)—Polygonum salicornioides, tuberculate achene surface; (I)—P. aridum, three linear styles connate at base. (J)—A. toktogulica, three styles connate at base. (K)—Bactria ovczinnikovii, three styles connate at base. (L)—A. pungens, three styles with fimbriate-capitate stigmas. Scale bar = 300 μm for A, G, G–L; = 100 μm for B, I; = 30 μm for C–F, H. Images: O. Yurtseva. i. Pollen morphology The pollen chracteristics of Polygonum subsection Spinescentia, Bactria, and Atraphaxis are summarized in Table 3. Polygonum salicornioides, P. spinosum, P. aridum, and P. dumosum have prolate to subprolate pollen grains, which are tricolporate, elliptical in equatorial view, trilobed-circular in polar view; colpi are distinct, long, narrow and deep; ora are distinct, lalongate or circular (Fig. 16).

172 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. % of per forated pits 95–99 10–15 10 20–50 10–99 50 2–5 20–30 10 10–25 Number of pits in a row/ lumina 1 1 1(2) 3–8 1–2(5) 1–6 2–7(10) 5–10 1(2) 1(2) Diameter of perforations, µm 0.1–0.2 0.1–0.3 0.1–0.3 0.1–0.4 0.2–0.6 0.2–0.6 0.1–0.2 0.1–0.6 0.1–0.2 0.1–0.8 Space between depressions, µm 0.2–0.3 0.2–0.4 0.2–0.4 0.1–0.2 0.1–0.2 0.1–0.2 0.2–0.4 0.1–0.3 0.2–0.4 0.7–1.7 Diameter of lumina/ grooves, µm 0.3–0.7 0.4–0.7 0.6–0.9 0.6–0.9 1.0–1.5 1.0–1.5 0.4–0.6 0.4–0.6 0.6–0.9 0.8–1.5 s.s. striate-perforate striate-perforate striate-perforate microreticulate-foveolate, lumina with 4–6 angular pits, rarely perforated microreticulate-foveolate to foveolate-perforate Sporoderm ornamentation foveolate-perforate to (punctate) tectate-perforate foveolate, foveolate- perforate, microreticulate- foveolate foveolate, foveolate- perforate, microreticulate- foveolate microreticulate-foveolate to striate-perforate reticulate-perforate to striate-perforate Atraphaxis , and spheroidal to oblong-spheroidal spheroidal to oblong-spheroidal spheroidal to oblong-spheroidal spheroidal to oblong-spheroidal spheroidal to oblong-spheroidal Pollen shape spheroidal to prolate prolate to subprolate prolate to subprolate prolate to subprolate spheroidal to oblong-spheroidal Spinescentia subsection 1.13 1.19 1.16 1.18 1.13 P/E mean 1.47 1.19–1.81 1.67 1.65 1.86 1.15 1.05–1.34 Polygonum , Bactria Equatorial µm) (E, diameter mean min-max 18.6 16.0–21.1 18.0 17.7–18.3 16.5 16.3–16.7 16.4 24.5 24.1–29.5 26.6 25.4–27.4 25.8 24.1–29.2 31.2 29.7–34.4 24.9 23.4–26.3 25.2 22.2–26.9 Polar axis (P, µm) Polar axis (P, mean min-max 27.4 25.2–29.1 30.1 27.2–33.1 27.2 22.4–32.0 30.5 28.2 26.4–31.0 30.2 29.5–31.1 30.7 28.5–32.1 36.3 31.8–40.4 29.5 28.0–30.7 28.45 25.6–29.6 Selected pollen characteristics of 3. a b le Species Polygonum salicornioides spinosum P. aridum P. dumosum P. Atraphaxis toktogulica A. atraphaxiformis A. ariana A. frutescens Bactria ovczinnikovii Bactria lazkovii T

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 173 Figure 16. Tricolporate pollen grains of Polygonum subsection Spinescentia, equatorial view (SEM): (A–C)—P. salicornioides (Kotschy 468, LE), foveolate to perforate (punctate) pollen surface. (D–E)—P. spinosum (Bornmüller 5083, LE), foveolate to perforate (punctate) pollen surface. (F, I)—P. dumosum (Kotschy 242, LE), striate-perforate pollen surface. (G–H)—P. aridum (Sawers, 1868, Haussknecht s.n. LE), foveolate, foveolate-perforate to microreticulate-foveolate pollen surface. Scale bar = 3μm. Images: E. Severova & O. Yurtseva.

The sporoderm surface of Polygonum subsection Spinescentia was described as reticulate-perforate (Tavakkoli et al. 2015), however precise definition of sporoderm ornamentation requires some preliminary comments. According to Punt et al. (2007) and Hesse et al. (2009), a reticulate pollen surface consists of lumina (or other depressions) wider than 1 μm, which are bordered by narrow elements (muri); a microreticulate pollen surface has lumina smaller than 1 μm (Punt et al. 2007). A foveolate pollen surface consists of more or less rounded depressions or lumina more than 1 μm in diameter spaced by the distance greater than their width. A tectate-perforate (punctate) pollen surface has the holes in the tectum less than 1 μm in diameter (Punt et al. 2007, Hesse et al. 2009). When the lumina or depressions are smaller then 1 μm, are spaced by the distance equal to their diameter, and perforated, the discrimination between these types is difficult. The sporoderm surface of P. salicornioides, P. aridum, and P. spinosum has 4–6 angular or rounded lumina or foveolae less than 1 μm in diameter (0.3–0.9 μm), which are sharply defined or smoothed at edges and spaced by the distance 0.1–0.4 μm (e.g. less than the diameter of the lumina or foveolae) (Fig. 16A–E, G–H). Some lumina or foveolae have small perforations 0.1–0.4 μm in diameter at the bottom. The perforations are singular or rarely double (Table 3). The variability of the lumina size and the distance between the lumina, as well as the gradual transition from 4–6 angular lumina with sharply defined edges to rounded lumina with smoothed edges create additional difficulties in objectively establishing the boundaries of the lumina and in measuring of the spaces between them. Besides, the presence of perforations depends on the deposits of sporopollenin on the pollen surface.

174 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. Therefore, according to terminology by Punt et al. (2007) and Hesse et al. (2009), the sporoderm surface of P. salicornioides, P. spinosum, and P. aridum can be equally described as microreticulate-foveolate, foveolate, or foveolate-perforate, with a full range of transition types between them.

Figure 17. Tricolporate pollen grains of Atraphaxis and Bactria, equatorial view (SEM): (A–C)—A. toktogulica (Ajdarova et al. s.n. LE), reticulate-perforate to striate-perforate pollen surface. (D–E)—A. atraphaxiformis (Abdusaljamova 65, LE), striate-perforate pollen surface. (F)—Bactria ovczinnikovii (Nepli et al. s.n. LE), microreticulate-foveolate pollen surface. (G)—A. ariana (Gorelova s.n. LE), striate-perforate pollen surface. (H–I)—A. frutescens (Resnichenko 145, MW), striate-perforate pollen surface. Scale bar = 10 μm for A, D, G–H; = 1 μm for B; = 3 μm for C, E, F, I. Images: E. Severova & O. Yurtseva.

In contrast, P. dumosum has a striate-perforate sporoderm surface, or a transitional type from the microreticulate- foveolate to striate-perforate sporoderm surface (Fig. 16F, I). Shallow grooves 0.6–0.9 μm wide are formed by 3–8 lumina arranged in a row and divided by narrow, smoothed striae. The striae are oriented meridionally or randomly, the grooves bear the rows of small rounded perforations (Table 3). The variant detected in P. dumosum is close to the sporoderm surface of Atraphaxis atraphaxiformis, A. tortuosa, and A. aucheri all having the smoothed striae divided by shallow grooves with small perforations (Fig. 17D–E, Table 3), or to that of A. toktogulica, which has the sporoderm surface transitional from the reticulate-perforate to striate- perforate (Fig. 17A–C, Table 3) (for more detail see Yurtseva et al. 2014). In A. toktogulica, lumina are either singular, 1.0–1.5 µm wide, or 2–5 lumina are arranged in rows and form the grooves that are divided laterally by hardly visible smoothed striae. Half of the lumina have single, rarely two perforations at the bottom. In contrast, Atraphaxis ariana (Fig. 17G) has a striate-perforate sporoderm surface with distinct striae divided by deep grooves with the rows of 2–7(10) pits or small perforations at the bottom, which is typical of the majority of Atraphaxis species, for instance, A. frutescens (L.) Koch (1872: 360) (Fig. 17H–I).

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 175 The microreticulate-foveolate sporoderm surface found in three species of Polygonum subsection Spinescentia, was also detected in Bactria. Bactria ovczinnikovii has spheroidal to oblong-spheroidal pollen grains with a microreticulate- foveolate sporoderm surface (reticulato-foveolate in Yurtseva et al. 2014) (Fig. 17F; Table 3). It has the lumina 0.6–0.9 μm in diameter with 4–6 angular pits, which are sharply defined at the edges and spaced 0.2–0.4 μm apart. Some pits have perforations 0.1–0.2 μm in diameter, mainly single at the lumina.

Figure 18. (A)—Strict consensus of 61 most parsimonious phylogenetic trees; tree length = 90 steps; CI = 0.6000; RI = 0.8302, recovered from a standard MP analysis of the morphological matrix of Atraphaxis s.l. (Appendix 3). All 27 characters are parsimony informative. (B)—Strict consensus of two nested most parsimonious hierarchies of patterns; length = 8328 steps; CI = 0.8521; RI = 0.8264), recovered from a MP analysis of the 3TS representation of 27 characters’ morphological matrix of Atraphaxis s.l. (Appendix 3). The number of the characters (3TS) is equal to 7096, all are parsimony-informative. The MP bootstrap values are indicated below branches (A and B). Image: E. Mavrodiev.

Bactria lazkovii is characterized by a great variability of sporoderm ornamentation within a pollen sample. Besides the microreticulate-foveolate sporoderm surface detected in B. ovczinnikovii, it also has the foveolate-perforate sporoderm ornamentation with rounded foveolae 0.8–1.5 μm in diameter spaced by the equal distance. Some pits have perforations 0.1–0.8 μm in diameter (for more details see Yurtseva et al. 2016a). j. The results of the standard MP and 3TA analyses Both conventional MP and 3TA analyses show a monophyletic and well-supported Polygonum subsection Spinescentia as a well-supported sister clade of a narrowly defined Atraphaxis (Fig. 18A, B). This is a key result of the study. The trees resulted from the both standard MP and 3TA have similar topologies (Fig. 18A, B), but in the terms of bootstrap support the 3TA topology (Fig. 18B) is essentially better resolved. The densely caespitose habit, terete wiry shoots, sessile linear-lanceolate leaf blades, truncate-tubular or acuminate- tubular ocreas, leafy texture of the perianth, which is totally covered with short linear trichomes, and linear stigmas are all optimized as synapomorphies of Polygonum subsection Spinescentia within the framework of the standard MP (Figs. 18A, 19–21). The members of the clade Atraphaxis s.s. share a petaloid perianth and striate-perforate sporoderm surface. The majority of the species have compact thyrses, lanceolate-tubular ocreas with two aristate lacinulas and a dentate- incised portion between lacinulas, filiform bases of the perianth tube, perianth segments differing in size (see more in Yurtseva et al. 2016a).

176 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. Within the clade Atraphaxis s.s., both MP and the 3TA analyses show a monophyletic and well-supported subclade comprising A. ariana from Badghyz, A. atraphaxiformis, A. toktogulica from Tian-Shan, and A. tortuosa from Mongolia (Fig. 18). All of these taxa share the terminal thyrses, the leaf blades that are undulate or crenulate at the margin, and the campanulate perianth with equal-sized segments, resembling in shape the perianths of Bactria ovczinnikovii and Polygonum subsection Spinescentia (Figs. 19–21). The optimization of morphological characters in the most parsimonous way showed, that the clade (1) Atraphaxis sensu Tavakkoli et al. (2015) (including paraphyletic Bactria, Polygonum subsection Spinescentia and Atraphaxis s.s.) and the clade (2) (P. subsection Spinescentia plus Atraphaxis s.s.) appear undefined by the standard synapomorphies or by the unique combinations of separate morphological traits (Figs. 19–21).

Discussion a. Concordance of topologies based on morphological and molecular data The results of both conventional MP and 3TA are congruent with topologies from previous molecular treatments of the same taxonomic complex (Tavakkoli et al. 2015; Yurtseva et al. 2016a). All of the analyses agree that the monophyletic Polygonum subsection Spinescentia is a well-supported sister of a narrowly defined Atraphaxis (Fig. 18). Contrary to the molecular treatments of the complex (Yurtseva et al. 2016), within the clade Atraphaxis s.s. both the standard MP and 3TA analyses recognized a well supported subclade comprised of A. ariana from Badghyz Semi- Desert of the Central Asia, A. atraphaxiformis from the South-Western Tian-Shan, A. toktogulica from the Inner Tian- Shan, and A. tortuosa from the Inner Mongolia, China (Fig. 18A, B). The recognition of this subclade by both conventional MP analysis and 3TA is fairly consistent with the clear distinctions of its members from the rest of Atraphaxis in the floral morphology, sporoderm ornamentation, and tuberculate achene surface. These species seem to retain plesiomorphic character states for Atraphaxis s. s., such as a campanulate perianth with equal-sized oblong-elliptical tepals, a rather short (1.0–2.5 mm) funnel-form tube with a filiform basal part of a medium length, and capitate stigmas. Since the campanulate perianth with equal-sized tepals and a rather short funnel-form tube is present also in Bactria, Polygonum subsection Spinescentia, and some genera of Polygoneae [e.g. Polygonum (Komarov 1936), Muehlenbeckia Meisner (1836: 316; Brandbyge 1992, 1993), or Duma T.M.Schust. (Schuster et al. 2011a: 1061)], these features might be treated as shared plesiomorphies. The position of this subclade within the clade Atraphaxis in the topologies based on morphology is not exactly the same. Within the topology that resulted from the standard MP analysis, this subclade appeared as a sister to the rest of the narrowly defined Atraphaxis (Fig. 18A). On the 3TA tree this subclade has a higher support, however its position is different (Fig. 18B). Atraphaxis teretifolia (Popov 1935: 24) Komarov (1936: 526) assigned initially to the genus Physopyrum Popov (1935: 23) and later to the monotypic section A. sect. Physopyrum (Popov) Lovelius is sister to the rest of the genus Atraphaxis. This position is consistent with strong morphological differences of A. teretifolia from the remaining species of Atraphaxis in ocrea and leaf morphology, and perianth having an extremely short filiform tube and concave membranous inner segments spheroidally surrounding the achene (more in Yurtseva et al. 2016a). Atraphaxis badghysi from Badghyz Semi-Desert of the Central Asia, which in some aspects is morphologically similar to A. ariana from the same region, goes next and is a sister to the rest species of Atraphaxis on the 3TA tree (Fig. 18B). It has almost equal-sized segments and a filiform perianth tube of a medium size (more details in Yurtseva et al. 2016a). It is noteworthy, that A. teretifolia is sister to the rest of Atraphaxis in plastid topology by Zhang et al. (2015) based on five regions of plastid DNA, but missing A. ariana, A. atraphaxiformis, A. toktogulica, and A. tortuosa. Atraphaxis badghysi is nested in one of two major subclades of Atraphaxis in the plastid topology by Zhang et al. (2015) and in own plastid topology based on three regions of plastid DNA, however it is grouped with A. ariana in the ITS-based topology (Yurtseva et al. 2016a). As we mentioned above, the species with a campanulate perianth do not form a distinct subclade within Atraphaxis by the results of own ML and BI analyses based on either ITS region, or combined plastid regions (Yurtseva et al. 2016a, b). Furthermore, the positions of individual species are distinct in the ITS-based trees and plastid trees. Due to a limited number of studied regions of plastid DNA and a fairly problematic ITS region (more in Yurtseva et al. 2016a, b), at the moment we have no grounds to treat this group as a single taxon within the genus Atraphaxis s.s.

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 177 Comparing different types of data, we have no evidence that the grouping of the species of Atraphaxis with a campanulate perianth results from their close genetic relationship, but we assume that they share plesiomorphic morphological traits of Atraphaxis in the early stages of its intrageneric diversification. Local distribution of these taxa might reflect a reduction of the areas of these previously widespread species. Both the standard MP and 3TA seem to have established a slightly better congruence with the intuitive vision of the whole complex, in comparison to the results of ML and BI treatments of the studied molecular datasets (Yurtseva et al. 2016a, b). Keeping in mind a better resolution of the 3TA topology (Fig. 18B), we conclude that this method might outperform the standard Parsimony in cases of vague and morphologically complicated complexes such as Atraphaxis and allies. b. Morphological distinctions of Polygonum subsection Spinescentia Our study showed clear morphological distinctions of Polygonum subsection Spinescentia from Bactria and Atraphaxis in the habit and life history, morphology of vegetative and fertile shoots, ocreas, perianths, shortly puberulent tepals, and some other characters (summarized in Tables 2–3, see also Figs. 19–21). Polygonum subsection Spinescentia differs by its densely caespitose habit, terete wiry shoots, almost sessile linear- lanceolate leaf blades, truncate-tubular or acuminate-tubular ocreas, a perianth completely velutinous-puberulent on the outside with short simple trichomes, the leafy consistence of oblong-elliptical or oblong-ovate tepals, and linear styles with poorly developed stigmas. These conventional synapomorphies were treated to support the generic rank of this group, named Persepolium O.V.Yurtseva & E.V.Mavrodiev gen. nov. here. Atraphaxis s.s. comprises stout shrubs or undershrubs with compact bracteose thyrses, leathery leaf blades slightly undulating at the margins, lanceolate-tubular ocreas with two aristate lacinulas connected by a dentate-incised middle portion, petaloid perianths with mostly long (1–7 mm) filiform basal parts of the perianth tubes. These morphological traits well discriminate Atraphaxis s.s. from Persepolium. Bactria are dwarf shrubs with leathery leaf blades, frondulose thyrses, bilacerate ocreas, campanulate perianths deeply divided in 5(6) equal-sized segments that are papillate only at the margins, and have a short perianth tube with a nearly invisible filiform basal portion. Most of these features were considered as conserved initial character states for the clade Atraphaxis sensu Tavakkoli et al. (2015) including Bactria, Polygonum subsection Spinescentia and Atraphaxis s.s. On the contrary, neither the clade combining paraphyletic Bactria, Persepolium, and Atraphaxis, nor the clade combining Persepolium and Atraphaxis are defined by the standard synapomorphies or unique combinations of morphological traits (Figs. 19–21). Therefore, the circumscription of Atraphaxis sensu Tavakkoli et al. (2015) cannot be justified from the morphological standpoint. c. Ecology and distributions The distribution of Persepolium is restricted to the Zagros Mountains in West and South Iran. The flora of the Zagros Mountains is fairly diverse and also highly autochthonous, with a high level (ca. 46%) of endemism (Noroozi et al. 2008). Zagros has a semi-arid temperate climate, which corresponds to the continental variation of the Mediterranean climate, with a snowy, cold winter and a mild rainy spring followed by a dry summer and autumn (Frey & Probst 1986, Heshmati 2007). The annual precipitation ranges from 400 to 800 mm, and the annual average temperatures are 5–15°C. The rainy period is from November to May, followed by a dry period between May and October with rare precipitation. The winters are severe, with temperatures often dropping below −25°C. This climate is favorable for oak forests and mountain forest steppe formed by Quercus brendii, Pistacia, Amygdalus, Acer, Craetaegus, and Lonicera at elevations of 800–2000 m.a.s.l. The alpine vegetation above the timberline is defined by prostrate shrub communities, Prangos communities, and thorn-cushion subalpine formations (Wrigth et al. 1967, Heshmati 2007, Noroozi et al. 2008). Polygonum dumosum was found near the ruins of Persepolis at elevations of 1600–1700 m a.s.l. with an annual precipitation of 305 mm, but it also grows at 3000–3700 m a.s.l. in the subalpine belt of the Kerman mountains, where the annual precipitation does not exceed 400 mm; P. aridum grows on grassy sandy slopes of high ridges at elevations of 2500–3400 m a.s.l. in Fars; P. spinosum endemic to the Kerman mountains reaches 3400–3900 m a.s.l.; P. salicornioides was found at elevations of 1000–2500 m a.s.l. These plants occupy xerophytic areas covered by graminoides and located at hill tops, ridges, and windswept slopes. Because of overgrazing these species are potentially endangered and vulnerable.

178 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. Figure 19. (A–D)—Most parsimonious optimizations (Maddison & Maddison, 2011) of the selected morphological traits using topology resulted from the standard MP analysis of the 27 characters’ morphological matrix of Atraphaxis s.l. (Fig. 18A, Appendix 3). All character states were treated as “unordered” Image: E. Mavrodiev.

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 179 Figure 20. (E–H)—Most parsimonious optimizations (Maddison & Maddison, 2011) of the selected morphological traits using topology resulted from the standard MP analysis of the 27 characters’ morphological matrix of Atraphaxis s.l. (Fig. 18A, Appendix 3). All character states were treated as “unordered” Image: E. Mavrodiev.

180 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. Figure 21. (I)—Most parsimonious optimizations (Maddison & Maddison, 2011) of the selected morphological traits using topology resulted from the standard MP analysis of the 27 characters’ morphological matrix of Atraphaxis s.l. (Fig. 18A, Appendix 3). All character states were treated as “unordered” Image: E. Mavrodiev.

Bactria ovczinnikovii and B. lazkovii are local endemics of the South Pamir and Central Tian-Shan mountains (Yurtseva et al. 2016a). They are petrophytes or chasmophytes growing in the belt of forest steppe (“shibliak”) or semi- shrub deserts at elevations of 600–1500 m a.s.l. Atraphaxis comprises ca. 35 species, which are widely distributed across North-Eastern Africa and Eurasia, ranging from South-Eastern Europe to Eastern Siberia, China and Mongolia. They grow in mountain forest steppes (scrub communities) and lowland semi-desert steppes (Lovelius 1978). In Iran, Atraphaxis occurs mainly in the North (Pavlov 1936, Rechinger & Schiman-Czeika 1968). Atraphaxis spinosa is a single species widely distributed throughout South-West Asia; however, in the Zagros area it grows in semi-deserts, open woodlands or mountain forest steppe communities of the Zagros foothills and the interior plateau at elevations of 920–1600 m a.s.l. (Rechinger & Schiman-Czeika 1968, Wright et al. 1967). Thus, Polygonum subsection Spinescentia, Atraphaxis and Bactria clearly differ from each other in terms of habitat and environmental preferences. d. The perianth and thyrse morphology of Bactria, Polygonum subsection Spinescentia, and Atraphaxis, and the principle of variable proportions The comparison of the perianth morphology of Bactria, Polygonum subsection Spinescentia and Atraphaxis s.s. allows for the hypothesis of formal transformations within the general framework of the Principle of variable proportions (Troll 1949, 1951, see Hagen & Kadereit (2002: 568), Mavrodiev (2009), and Ronse De Craene (2010: 47) for summaries of this concept and a different view point). Bactria has a deeply divided (to 4/5–8/10) campanulate perianth with five equal-sized tepals and a short tube (Fig. 6B–C), which is shared by some other genera of Polygoneae: Polygonum, Muehlenbeckia, and Duma. Persepolium and some Atraphaxis species (A. ariana, A. atraphaxiformis, A. toktogulica, and A. tortuosa) share the campanulate or urceolate perianths less deeply divided (to 2/3–3/4) into five equal-sized segments, and have a somewhat longer funnel-form tube with a conspicuous filiform basal part (Fig. 6A, D–F).

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 181 Finally, the majority of Atraphaxis species have a specialized perianth with the inner segments enlarged and widely spread in flowering, and a tube with a very long filiform basal part (Fig. 6G–I). Either the elongation of the tube, or the differentiation of the segments, or both are present in some other genera of Polygoneae, such as Knorringia (Czukavina 1966: 93) Hong (1989: 351), Reynoutia Houttuyn (1777: 639), Fallopia Adanson (1763: 274, 277), and Polygonum subsection Polygonella (Michaux 1803: 240) Ronse Decr. & S.P. Hong in Ronse De Craene et al. (2004: 340), and can be treated as a parallelism. This change in flower structure correlates with a shift in the position of the stamens. In Bactria with the shortest tube and the deepest perianth partition (4/5–8/10), the filaments are inserted towards the base of the receptacle formed by the fused bases of the tepals and lined inside by nectariferous cells. Persepolium and some Atraphaxis species (A. ariana, A. atraphaxiformis, A. toktogulica, and A.tortuosa) have the filaments inserted still deeply in the receptacle, but both the receptacle and the bases of the filaments are covered with a nectar-secreating tissue. On the contrary, the majority of the Atraphaxis species have the longest perianth tube with the longest filiform basal portion and a shallow receptacle at the top. Their filaments are inserted towards the upper edge of the receptacle, what makes pollen and nectar more available for pollinators. In other words, the flower structure of Bactria, Persepolium, and Atraphaxis s.s. can be easily transformed into each other, requiring only some changes in the size of their parts. These differences in floral morphology are congruent with the morphology of the thyrses, which are frondulose and more or less compact in Bactria, frondose or frondulose, elongated, with well spaced axillary cymes in Persepolium, and bracteose, more or less compact in Atraphaxis. The compact frondulose or bracteose thyrses of Bactria and Atraphaxis are consistent with petaloid perianths, which make the inflorescences more attractive and convenient to mass-pollination. e. The sporoderm surface of Bactria, Persepolium, and Atraphaxis as a diagnostic trait The microreticulate-perforate or foveolate-perforate sporoderm ornamentation typical for Bactria was detected in three species of Polygonum subsection Spinescentia. This type of sporoderm surface is present in a number of unrelated genera of Polygoneae: in Calligonum Linnaeus (1753: 530) and Pteropyrum Jaubert & Spach (1844: tabs. 107–109) from the tribe Calligoneae (Ge 1993, Bao & Li 1993, Hong 1995, Zhang & Xi 1997), in Fagopyrum Miller (1754: 113) (Van Leeuwen et al. 1988; Nowicke & Skvarla 1977, 1979) and Parapteropyrum tibeticum Li (1981: 330) (Bao & Li 1993, Van Leeuwen et al. 1988, Hong 1995) from the tribe Fagopyreae (Sanchez et al. 2011). The majority of Аtraphaxis species have a striate-perforate sporoderm surface with distinct striae divided by deep grooves with perforations in a row. This surface is unique in Polygoneae, although it was found in many non-related groups of angiosperms (Hesse et al. 2009). Among Atraphaxis, A. toktogulica has a sporoderm surface transitional from the reticulate-perforate to the striate- perforate, whereas A. atraphaxiformis and A. tortuosa have a striate-perforate sporoderm with smooth striae and shallow grooves, as does Persepolium dumosum. Due to the appearance of the striate-perforate sporoderm surface in the sister groups of Persepolium and Atraphaxis s.s. (Yurtseva et al., 2016a) we assumed that the microreticulate- perforate surface appears to be a plesiomorphic character state, while the striate-perforate sporoderm ornamentation is an apomorphic character state (Appendix 2). Transformation of the microreticulate-perforate sporoderm surface into the striate-perforate surface may be viewed as a result of arranging the adjacent lumina into rows and lifting their lateral borders (more in Yurtseva et al. 2014). The diversity of sporoderm ornamentation detected in Bactria, Persepolium, and Atraphaxis reduces the diagnostic value of this trait. However, the sporoderm ornamentation allows the exclusion Persepolium from the genus Polygonum, which partly demonstrates a similar thyrse and perianth morphology. The genus Polygonum with a broader circumscription including Polygonella Michx. (Ronse De Craene et al. 2004, Schuster et al. 2011b) has a number of quite different palynotypes, namely, the palynotype Avicularia with a psilate, micropunctate, microspinulose sporoderm ornamentation (Hedberg 1946, Hong et al. 2005, Brandbyge 1992); the palynotype Duravia with a dimorphic pollen surface: rugulate or foveolate with microspinules around the colpi, semitectate-reticulate at mesocolpia (Hedberg 1946, Hong et al. 2005); and the palynotype Pseudomollia with a dimorphic pollen surface: psilate around the colpi, verrucate at mesocolpia and poles (Hong et al. 2005). In addition, in plastid phylogenetic reconstructions the clade combining Polygonum (incl. Polygonella) and Duma is sister to the clade combining Bactria, Persepolium, and Atraphaxis (Schuster et al. 2011b, Yurtseva et al. 2016a). Therefore, the sporoderm ornamentation confirms that Persepolium is not related to Polygonum.

182 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. f. Polygonum subsection Spinescentia is likely a self-pollinated taxon According to Ronse De Craene & Smets (1991), a well-developed perianth and nectar-secreting tissue lining the receptacle and also present at the bases of filaments indicate entomophyly. On the other hand, simple leafy inflorescences with widely spaced cymes of flowers, an urceolate perianth, inner stamens which reach stigmas, the enclosure of the androecium and stigmas by the segments that do not widely open, and the lack of trichomes at the bases of the filaments are considered as arguments in favor of self-pollination. The genus Persepolium is characterized by frondose or frondulose thyrses with well spaced cymes of 10–20 cymes including 2–3 flowers, an inconspicuous urceolate or campanulate perianth with equal-sized tepals and a rather short perianth tube, a spacious receptacle lined inside with nectar-secreting tissue also covering the bases of the filaments, linear poorly developed stigmas, and pollen with poorly sculptured foveolate, foveolate-perforate, to microreticulate- foveolate sporoderm surface. This suite of morphological characters indirectly indicates self-pollination. Since the perianth segments enclose the stamens, which remain hidden inside the perianth throughout flowering, these species are likely visited by small non-specific pollinators that facilitate self-pollination. Persepolium has a purplish-green perianth with sepal-like oblong-elliptical, oblong-ovate, or oblong-spatulate segments, which are entirely covered with short simple trichomes on the outside. The sepal identity of the tepals is inferred from the rectangular or irregular epidermal cells and the numerous stomata interspersed with the epidermal pavement cells with a deep longitudinal or random cuticular striation, and some of the cells forming short simple linear trichomes. This resembles the epidermis of the sepals as described in Arabidopsis (Pelaz et al. 2000), and the leaf blades and annual shoots of Persepolium. A similar type of epidermal cells covers the inner surface of the lobes in Pteropyrum (Hong et al. 1998). The trichomes covering the outside of the perianth might perform a protective function in an arid climate by preventing superfluous transpiration, or may contribute to the inflow of water to the flower buds. In addition, these trichomes may play a tactile role for the recognition or grasping action by pollinators. In terms of habit, structure of shoots, inflorescences and ocreas, Atraphaxis ariana, A. atraphaxiformis, A. toktogulica, and A. tortuosa are Atraphaxis s.s. They have the same shoots, ocreas, thick leaf blades with undulating edges, and striate-perforate sporoderm ornamentation typical of the rest of Atraphaxis (except for A. toktogulica, which has a sporoderm surface transitioning from reticulate-perforate to striate-perforate). These species are locally distributed and geographically well separated from each other with A. ariana growing in the Badghyz Semi-Desert in Central Asia, A. toktogulica and A. atraphaxiformis occuring in Tian-Shan, and A. tortuosa in Inner Mongolia, China. These species likely retained plesiomorphic traits in perianth morphology, present in Persepolium, but possibly were less reproductively successful than the rest of Atraphaxis. Similarly to Persepolium, these species share the campanulate perianth with five equal-sized oblong-elliptical or oblong-ovate segments, the funnel-form perianth tube of medium size, and the filaments inserted rather deeply in the receptacle. Their perianth segments are not rotund or cordate as in many other species of Atraphaxis (see more in Yurtseva et al. 2016a), but they are already petaloid, white or brightly coloured, demonstrating a transitional state to the specialized perianth typical of Atraphaxis. Conical papillae covering the perianth tubes and the segment bases of these species are as long as the linear trichomes covering the perianth of Persepolium, but are twice as wide and have a more subtle tightly pressed cuticular striation. Conical papillae are present also on the perianth of some Polygonum species, Oxygonum, and Fagopyrum (Hong et al. 1998), that are distant from Atraphaxis in molecular phylogenetic trees (Sanchez et al. 2011; Schuster et al. 2011b, Yurtseva et al. 2016a). These papillae likely play a tactile role for recognition by pollinators, or allow them to grip the flower surface, or have effects on petal colour, petal reflexing, scent production, or petal wettability (Noda et al. 1994, Hong et al. 1998, Martin & Glover 2007, Ojeda et al. 2009, Whitney et al. 2009, 2011). Most of Atraphaxis species have more specialized flowers with glabrous petaloid segments arranged in two whorls of different size. The segments are broadly ovate, rotund, cordate, or reniform in shape, white, yellow, or brightly pink in colour. During flowering, the segments are spread out widely, providing access to the stamens and ovary for pollinators. By the time of fruiting, the two outer segments of the perianth are smaller and often reflected towards the pedicel, the inner segments are enlarged, upright and hide the mature achene. In Atraphaxis spinosa and A. fischeri, the inflated bases of the filaments are densely covered with conical thin- walled papillae. The trichomes associated with nectar-secreting tissue were detected also in Koenigia Linnaeus (1767: 3), Fallopia, Oxygonum Burchell (1822: 548), Calligonum, and Pteropyrum (Ronse De Craene & Smets 1991), in which they supposedly hold the nectar by capillarity action, or maintain nectar consistency. However, the thin-walled papillae present on the filaments of A. spinosa and A. fischeri likely serve as aids for grasping by pollinators, may play a tactile role in species-specific recognition, or could increase an inflow of water to the bases of the filaments during flowering, promoting the opening of the flower.

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 183 The showy compact bracteose thyrses and open flowers, the fairly specialized perianth with a long fifliform basal part of the tube and accrescent inner segments, the nectar-secreating tissue lining the receptacle inside and the filament bases adaxially, the fimbriate-capitate stigmas, and the papillae at the filaments indicate that the majority of Atraphaxis species are insect-pollinated, which is consistent with the opinion by Ronse De Craene & Smets (1991). These features possibly give advantages for autcrossing, successful seed reproduction and wider distribution in comparison with Bactria, Persepolium, and some Atraphaxis species with less specialized perianth, which are local endemics. The diversity of flower and inflorescence structure observed in Atraphaxis possibly indicates the different pollination modes in the species with accrescent inner segments and long tubes, as compared with part of Atraphaxis with a less specialized perianth. The brightly coloured or white accrescent petaloid segments are more attractive for pollinators and promote cross-pollination. The filiform basal portion of the tube contributes to the elongation of a straight pedicel, both serving to exert the perianth out of the compact thyrse formed by congested cymes of flowers. In Atraphaxis, the long tube fused to a gynophore does not contain nectar but has a purely mechanical function. The same feature is seen in Polygonum subsection Polygonella and Reynoutria Houttuyn (1777: 639) with spike-like bracteose thyrses. In fruiting, the long pendulous pedicels elongated by the filiform bases of the tubes may facilitate movement of fruits equipped with persistent perianth segments and may promote anemochory. The distinct shape of the stigmas, which are linear in Persepolium, capitate in part of Atraphaxis, and fimbriate- capitate in the majority of Atraphaxis also points to different pollination modes. One might assume that the differences in epidermis of the petaloid segments of Bactria lazkovii and Atraphaxis, or the sepaloid segments of Persepolium and B. ovczinnikovii might correspondingly be the result from the expression of the genes responsible for the identity of petals or sepals (e.g., Coen & Meyerowitz 1991, Pelaz et al. 2000, Theissen & Melzer 2007, Irish 2009, Landis et al. 2012, Chanderbali et al. 2016). Also the lack of papillae from the perianth surface of the majority of Atraphaxis species could correlate with MIXTA mutation (Noda et al. 1994, Martin et al. 2002, Martin & Glover 2007) as well as with the shift of pollination mode of these taxa in comparison to the species with equal-sized segments and conical papillae on the tube. However, more work is necessary to describe and understand the developmental patterns of the flower of Atraphaxis and related taxa, as well as to establish the proper context of such studies.

Conclusions

1. Both the conventional parsimony and the 3TA analyses of the morphological dataset of the narrowly defined Atraphaxis and related taxa demonstrated that the monophyletic Polygonum subsection Spinescentia is a strongly supported sister of the narrowly defined genus Atraphaxis, which is consistent with the results of molecular phylogenetic reconstructions. 2. We recommend accepting Polygonum subsection Spinescentia at the generic rank. 3. The genus Persepolium Yurtseva & Mavrodiev (=Polygonum subsection Spinescentia Boiss.), circumscribed to include five species, is established here as new to science.

Key to the genera Atraphaxis, Bactria, Persepolium, and Polygonum

1. Perennial or annual herbs, or undershrubs with internodal branching, terminal bracteose inflorescences with tightly congested cymes, perianth of 5 equal-sized or unequal segments, with long filiform basal part of tube. North America...... Polygonum section Duravia subsection Polygonella — Shrubs, undershrubs or herbs with branches not adnate to stems, inflorescence frondose or bracteose, terminal or lateral, cymes congested or spaced, perianth of 4–5 segments, equal or inner ones strongly enlarged...... 2 2. Annual, rarely perennial herbs with campanulate or urceolate perianth divided to 1/2–5/6 in five equal-sized petaloid segments, green along midveins, with wide white or anthocyanin-coloured margin, flat, obtuse, or cucullate and keeled. Ocreas tubular, lacerate or fimbriate, with 5–11 veins. Worldwide...... Polygonum section Polygonum and P. section Duravia subsection Duravia — Shrubs, dwarf shrubs, or undershrubs, perianth campanulate or urceolate, or with accrescent inner segments and long filiform tube. SW and Central Asia, Eurasia...... 3 3. Perianth 6.5–14.5 mm, mostly with four-five unequal segments (two-three inner segments in fruits are much larger than two outer segments), and filiform tube 2.5–7.5 mm long; rarely perianth campanulate, divided to 1/2–3/4 in five equal or subequal segments, with tube 1–3 mm long, the filiform basal part of tube no more than 0.4–1.0 mm long. The segments always are petaloid, thin, widen to ends, white or brightly coloured, fully enclosing the achene. Stamens are 6 to 8; styles 2 or 3. Shrubs or undershrubs with compact bracteose, rarely frondulose, terminal or lateral thyrses. Ocreas are 3–10 mm, tubular, with two veins, the upper part membranous, transparent, with two lateral aristate lacinulas connected by finely serrate-incised middle portion. Ocreolas in thyrses

184 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. are oblique-funnel form, membranous, transparent, with a small herbaceous outgrowth or a narrow keel. Mts of SW and Central Asia, steppes of Eurasia...... Atraphaxis — Perianth 2.0–6.5 mm, campanulate or urceolate, with 5(6) equal-sized segments, petaloid or leathery, tube widely funnel-form or cup-shaped, filiform basal part of tube does not exceed 0.3 mm. Stamens 8(9); styles 3. Ocreas lanceolate-tubular, split in two acuminate lacinulas...... 4 4. Dwarf shrubs with shoots never prickly, perianth divided almost to base (4/5–8/10) in 5(6) equal-sized segments petaloid, glabrous, with papillae only at segment edge. Pamir, Tian-Shan...... Bactria — Dwarf shrubs, undershrubs, or herbs, some with prickly shoots, with perianth divided to 1/2–3/4, fully puberulent or glabrous, at last case without papillae at segment edge...... 5 5. Caespitose undershrubs, or dwarf shrubs, some with prickly shoots. Perianth urceolate or campanulate, 2–6 mm long, fully densely shortly puberulent, divided to 2/3–3/4 in oblong-elliptical or ovate segments, gradually narrowed to the top, leathery (coriaceous), rigid, purplish-green, with narrow (less than 0.2 mm) membranous margin. Ocreas are 3–7 mm long, truncate-tubular or acuminate- tubular, membranous, shortly bidentate, later bilacerate, without veins, or with 2–6 veins. Endemics of Iran...... Persepolium — Small shrubs, undershrubs, or herbs, shoots not prickly. Perianth urceolate, 2–3 mm, glabrous or papillate at tube, divided to 1/2–3/4, segments petaloid, green with wide white or anthocyanin-coloured margin, flat, obtuse, or keeled and cucullate. Ocreas are 3–10 mm, tubular, membranous, with 5–11 veins, lacerate-fimbriate. Mts of SW and Central Asia...... Polygonum section Pseudomollia

New names and combinations

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.

Key to the species of Persepolium

1. Dwarf shrub with prickly divaricately-branched lignified (indurate) shoots, branchlets with internodes 1–2 mm long, without ribs. Leaf blades are linear-lanceolate, acute, early deciduous. Ocreas oblique-tubular, acute, incised...... P. spinosum — Dwarf caespitose undershrubs with unarmed intensively branched herbaceous annual shoots rising up from a many-headed cau- dex...... 2 2. Leaf blades leathery, ovate to oblong-lanceolate, gradually reduced to the top of the shoot. Low leaf blades persistent...... P. khajeh-jamalii — Leaf blades linear-lanceolate to oblong-elliptical, fleshy, early deciduous...... 3

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 185 3. Annual shoots 2–3 mm in diameter, pointed but unarmed, with fleshy internodes with prominent ribs 10–15 mm long, in nodes slightly constricted. Ocreas are 2–4 mm long, truncate-tubular, later incised. Leaf blades are oblong-elliptical, obtuse, a bit fleshy. Perianth urceolate, densely velutinous-puberulent, mature flower 4–6 mm long droops at long pedicel...... P. salicornioides — Annual shoots 1.0–1.5 mm in diam., wiry, glabrous or minutely papillate; medium internodes 10–15 mm long, not inflated, terete. Leaf blades are linear or oblong-elliptical, obtuse, gradually reduced to the top of the shoot, early deciduous. Perianth campanulate, funnel-shaped...... 4 4. Leaf blades linear-lanceolate, shorter than 1–3 mm long, almost glabrous. Upper internodes constricted to 1–2 mm long, genicu- late; upper nodes leafless in flowering. Mature flowers are directed upward at short pedicels hidden in ocreas, achene is exserted from the perianth...... P. aridum — Leaf blades linear-elliptical, revolute at margin, 7–10 mm long, densely puberulent, gradually reduced to the top of the shoot. Up- per leaf blades appear as short ciliate outgrowths with two lateral lacinulas. Upper nodes are leafy in flowering. Mature flowers hang up at long bent pedicels, fully hide the achenes...... P. dumosum

1. Persepolium salicornioides (Jaub. & Spach) O.V.Yurtseva & E.V.Mavrodiev, comb. nov.

≡ Polygonum salicornioides Jaubert & Spach (1844–1846 [1845]: tab. 123). ≡ Atraphaxis salicornioides (Jaub. & Spach) S. Tavakkoli & Kaz. Osaloo in Tavakkoli et al. (2015: 1167). Type:—[IRAN. Fars:] Persia Austr.: Inter Fasa and Shiraz, 1867, Aucher-Eloy 5277 (K [K000830420!], lectotype designated by Rechinger & Schiman-Czeika (1968: 73); isolectotypes P [MNHN-P-P00734373!, MNHN-P-P00734374!]).

Selected specimens examined:—[IRAN. Fars:] Persia Austr.: In alpe Kuh-Delu. 10 jun. 1842 (Ed. R.F. Hohenaker, 1845), Th. Kotschy 468, sub Polygonum oligophyllum Boiss. (LE [LE00011673!], P [MNHN-P-P00734375!, MNHN- P-P00734376!, MNHN-P-P00734377!], K [K000830421!], MO [MO-277007, MO-277008], E [E00472163]). Distribution:—IRAN. Chaharmahal-e Bahktiary: Kuh-e Jahanbin; Kuhgileuye and Boirahmad. Kerman: Rabor; Jebal Barez; Kuh-e Sabz Pushan; Kuh-e Saverz. Fars: Schiraz; Buknabad b. [Kalaf Puschom] (K000830419!); Bamu; Maharlu; Kuh-e-Bamu bei Shiraz (K000830418!); Kuh Delu (Darengan); Sivand; Kuh Chah Siah prope Sivand, Tal- e Khosravi; Kuh Bungi prope Dasht-e Arzhan; Kuh-e Nil. Hormozgan: Bokhon, Tashgerd, Bohem Mts. (partly by Rechinger & Schiman-Czeika 1968, Mozaffarian 2012). Endemic of Iran. Ecology:—The species grows at elevations of 1000–2500 a.s.l.

2. Persepolium aridum (Boiss. & Hausskn.) O.V.Yurtseva & E.V. Mavrodiev, comb. nov.

≡ Polygonum aridum Boiss. & Hausskn. in Boissier (1879: 1042). ≡ Atraphaxis arida (Boiss. & Hausskn.) S.Tavakkoli & Kaz. Osaloo in Tavakkoli et al. (2015: 1167). Type:—[IRAN. Kohgiluyeh and Buyer Ahmad] Persiae Australis. In graminis arenosis Kuh Sawers Nur [Kuh-e-Saverz], 8000’, 07.1868, C. Haussknecht s.n. (G-BOIS [G00762458!], lectotype designated here by Yurtseva; isolectotypes JE [JE00026231, JE00026232]). Other syntypes: [IRAN. Kohgiluyeh and Buyer Ahmad] Luristan M. Sawers 8000’, 07.1868, C. Haussknecht s.n (LE!, P [MNHN-P-P00734372 sub Polygonum salicornioides!, MNHN-P-P00734294!]); [Kohgiluyeh and Buyer Ahmad] M. Sawers in apricis 8–10000’, Jul. 1868, C. Haussknecht s.n. (G-BOIS [G0072459!], K [K000830424!]); [Kohgiluyeh and Buyer Ahmad] Kuh-Sawers, 1868, C. Haussknecht s.n. (B [B-100279389!]). Selected specimens examined:—[IRAN. Lorestan] Persia, Luristan: Kuh-e-Ker [Kuh Enhker], in rupestr. frigid., 10000’, July 1868, C. Haussknecht s.n. (LE!); ibidem, 9000’, July 1868, C. Haussknecht s.n. (P [MNHN-P- 00734295!]). Distribution:—IRAN. Esfahan: Semirum, Abmalakh, Kuh-e Dena; Gardaneh Rokh. Chaharmahal and Bakhtiary: Saba kuh, Kerman: Kuh-e Hezar (Hazaran). Fars: Kuh Tschan Siah b. Siwend (Sivand). (K000830423!); Nurabad, Doshnman Ziary reg.; Shiraz; Eghlid to Ardakan. Kohgiluyeh and Buyer-Ahmad: Kuh-e-Nil, Kuh-e-Saverz. Yazd: Ardakan; Rücken d. Kuh Buchara (K000830422!) (partly by Rechinger et Schiman-Czeika 1968, Mozaffarian 2012). Endemic of Iran. Ecology:—The species grows on grassy sandy or gravelly slopes of high ridges at elevations of 2500–3400 m a.s.l.

3. Persepolium dumosum (Boiss.) O.V.Yurtseva & E.V.Mavrodiev, comb. nov.

≡ Polygonum dumosum Boissier (1846: 83). ≡ Atraphaxis dumosa (Boiss.) S.Tavakkoli & Kaz. Osaloo in Tavakkoli et al. (2015: 1167). Type:—[IRAN. Fars] Pers. austr., prope ruinas u. [urbi] Persepolis, 16 April 1842, Th. Kotschy 242 (Ed. R.F.Hohenacker 1845) (G-BOIS

186 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. [G00762457!], holotype; isotypes G [G00418277, G00418278], LE!, LECB (Herb. Th.Bienert)!, B [B100279383!, B100279382!], K [K000830425!], M [M0243599!, M0243600!], P [MNHN-P-P00734319!, MNHN-P-P00734320!, MNHN-P-P00734321!], MO, FI, WAG, NY, HAL, E, GOET).

Distribution:—IRAN. Chaharmahal and Bakhtiari: Shakr-e Kurd, Shalamzar, Aghsabs; from Lordegan to Yasuj, Mayamand, Margh-e Chenar; Gandoman. Kohgiluyeh and Buyer-Ahmad: Kottuk. Kerman: Kuh-e Japar, Bornmüller 5081. Fars: Takht-e Jamshid (Persepolis), Kuh-e Ayub, Wendelbo 790 (B, LE!); Shiraz, Park-e Bamu; Kuh-i-Bamu, N.E. of Shiraz; Dasht-e Arzhan; (?) Derabun (partly by Rechinger et Schiman-Czeika 1968, Mozaffarian 2012). Endemic of Iran. Ecology:—The species grows at elevations of 1600–3700 m a.s.l.

4. Persepolium spinosum (H.Gross.) O.V.Yurtseva & E.V.Mavrodiev, comb. nov.

≡ Polygonum spinosum Gross (1913: 340). ≡ Atraphaxis kermanica S.Tavakkoli & Kaz. Osaloo in Tavakkoli et al. (2015: 1167). Type:—[IRAN.] Pers. Austro-orientalis: prov. Kerman: in jugis alpinis montis Kuh-i-Nasr. 3400–3900 m s.m., 24.05.1892, J. Bornmüller 5083, sub Polygonum salicornioides Jaub. & Spach (K [K000830410!] lectotype designated by Rechinger & Schiman-Czeika (1968: 73); isolectotypes B [B100279336!, B100279327!, B100279329!, B100279330!, B100279331!], LE!, E [E00319884], JE [JE00026181]).

Other syntypes:—[IRAN.] Persia austro-orientalis: prov. Kerman: dist. Rahbur, in monte Kuh-i-Diwani, 2800 m, 29.08.1892, Bornmüller 5084, sub P. salicornioides Jaub & Spach (B [B100279328!]); Kerman: In monte Kuh-i- Diwani ditioni Rahbur, 2800 m, 29.07.1892, Bornmüller5084 (JE [JE00026189]); Persiae austro-orient.: prov. Kerman: Kerman; Kuh-i Dschupar in saxosis alpinis, 3500 m, 10.06.1892, Bornmüller 5084b (B [B100279334!]). Distribution:—[IRAN.] Kerman: Kuh-e Hezar (Hazaran) Zehrud Bala (E00472205); Kuh-e Khabr; Lalezar; Kuhbanan, Mt. Davedan. Fars: Deh-e Bala, Yazd: Shir-Kuh (partly by Rechinger & Schiman-Czeika 1968, Mozaffarian 2012). Endemic of Iran. Ecology:—Endemic of Kerman Mts, reaches elevations of 3400–3900 a.s.l.

5. Persepolium khajeh-jamalii (Khosravi & Poormahdi) O.V.Yurtseva & E.V.Mavrodiev, comb. nov.

≡Polygonum khajeh-jamalii Khosravi & Poormahdi (2008: 477), “khajeh-jamali”. ≡Atraphaxis khajeh-jamalii (Khosravi & Poormahdi) S.Tavakkoli & Kaz. Osaloo in Tavakkoli et al. (2015: 1167). Type:—IRAN. Fars province: Abadeh Tashk, Khajeh-Jamali, chromite mine, 1998 m, 29°48’46’’N, 53°51’53.64’’E, 14.06.2004, Khosravi et al. 23954 (Herbarium of Schiraz University, holotype).

Distribution:—IRAN. Fars: Abadeh Tashk, Khajeh-Jamali; Sarvestan, Post-e Chenar; Kerman: Kuh Panj Bardsir, Derkht Gaz (by Rechinger & Schiman-Czeika 1968, Mozaffarian 2012, Khosravi & Poormahdi 2008). Endemic of Iran.

Acknowledgements

We wish to thank the curators of the Herbarium of V. L. Komarov Botanical Institute (LE) Drs V. I. Dorofeev and O. V. Cherneva, the curator of the Herbarium of St. Petersburg University (LECB) Dr. V. A. Bubyreva, and the Curator of the Herbarium of Lomonosov Moscow State University Dr. A. P. Seregin for their kind permission to investigate the samples. We thank Dr. Hajo Esser (Botanische Staatssammlung München, Munich, Germany) and Dr. Laurent Gautier (Conservatoire et Jardin botaniques, Ville de’ Genéve, Geneva, Switzerland) for sending the images of Polygonum dumosum, P. aridum and for helpful advice. We would like to thank O. A. Volkova, A. G. Platonova, and the staff of the Laboratory of Electron Microscopy of M. V. Lomonosov Moscow State University, Faculty of Biology for technical assistance in LM and SEM investigations. We would like to thank Dr.T. E. Kramina for providing some references and Prof. D. D. Sokoloff for some remarks. The investigation of herbarium material was supported by the Russian Science Foundation (project № 14–50–00029), the SEM investigations were carried out in accordance to a Government order for the Lomonosov Moscow State University (project No. AAAA-A16-116021660045-2). We would like to thank Dr. David Williams (London Museum of Natural History) for his helpful comments on the analytical paragraphs of the ms.

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 187 We are grateful to Prof. D. E. Soltis (University of Florida, USA) and Prof. P. S. Soltis (University of Florida, USA) for their various support. We warmly thank the anonymous reviewers for their useful comments, which significantly improved the manuscript, and Dr. Alexander Sennikov for his help in editing the manuscript.

References

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Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 191 Appendix 1. Origin of the material used for LM and SEM micrographs.

Atraphaxis ariana (Grigorj.) T.M.Schust. & Reveal. TURKMENSKAYA SSR. [Badghyz, Kushka d.] v. Morgunovsky, 25.04.1988, Gorelova s.n. (LE); TURKMENISTAN [Badghyz] Kushka, 17.05.1934, Androsov s.n. (LE). Atraphaxis aucheri Jaub. & Spach. [IRAN] W. Persia, Gilan: Mulla-Ili, 15.05.1904, Gadd 341 (LE). Atraphaxis atraphaxiformis (Botsch.) T.M.Schust. & Reveal. UZBEKISTAN. [Alay]: Turkestan Ridge, the river Isphara, above v. Vorukh, 07.1970, Kamelin 532 (LE); TAJIKISTAN. [Alay]: Turkestan ridge, confl. of the rivers Kshemysh and Bel-Su, 03.07.1963, Abdusaljamova 65 (LE). Atraphaxis avenia Botsch. SOUTHERN TAJIKISTAN. [Khatlon reg. Shuroabad d.]: Mts surrounding v. Bag at the river Pyandj, red sandstones at the right bank of the river Shpilyau, 1.06.1960, Botschantzev, Egorova 779 (LE). Atraphaxis badghysi Kult. TURKMENISTAN. E Kara-Kum: Tej-Murgab interfluve, 15 km to S from Kureli to Gumbezli, 4.05.1956, Akimuradov s.n. (LE). Atraphaxis billardierei Jaub. & Spach. TURKEY. Prov. Nevsehir: Ürgüp. Rocky slopes, 1300 m a.s.l., 24.05.1960, Stainton & Henderson 8469 (LE). Atraphaxis caucasica (Hoffm.) Pavlov. GEORGIA. Mtskheta d.: in cliff Armazi, 17.06.1969, Grebenschikov et al. s.n. (MW). Atraphaxis fischeri Jaub. & Spach. RUSSIA. Volgograd: Mamaev Kurgan, 18.06.2016, O.V.Yurtseva s.n. (MW); RUSSIA. Volgograd: Kirov. d., Bolshaya Otrada, 07.05.2009, Klinkova, Suprun 2 (MW). Atraphaxis frutescens (L.) C.Koch. MONGOLIA. The Mongol Altay: Bayan-Olуgiy aimag, 15 km to N of Bulgan, Mt. slope in the estuary of the Ikh-Dzhegalanta, right inflow of the river Bulgan, 2100 m a.s.l., 27.08.1983, Gubanov 7281 (MW); RUSSIA. Altay: Semipalat. d., Ust-Kamenogorsk, 1912, Resnichenko 145 (MW). Atraphaxis laetevirens (Ledeb.) Jaub. & Spach. KAZAKHSTAN. Talas Alatau: Aksu-Dzhabagly, pass Kshy-Kaindy, above Akshy- Aksu, S slopes, 11.08.1948, Kultiasov s.n. (MW). Atraphaxis manschurica Kitag. CHINA. The Inner Mongolia: between u. Tunlyon and u. Dunkehoutsy, v. Shuan-Fumiao, 23.06.1951, Lion 3156 (LE). Atraphaxis muschketowi Krasn. KAZAKHSTAN. Tian-Shan, Zaily Alatau: near Alma-Ata, Mt. Kok-Tebe, 24.05.1998, Majorov 98–24 (MW). Atraphaxis pungens Jaub. & Spach. RUSSIA. Tuva ASSR: Ulug-Khem d., Ridge Uyuk, stony steppe near Bayan-Kolsky parom, 6.08.1976, Lomonosova & Ivanova 2408 (MW); RUSSIA. Krasnoyarsky kray, Khakassia: 12 km to SW of Charkov, 1.07.1953, Polozhyi et al. s.n. (MW); RUSSIA. Khakassia: Askiz d., flood plain of the left bank of the river Askiz opposite to the village Kazanovka, along the road to the village Bolganov (Anchil-Chon), N 53º13’18’3” E 90º03’13’4”, 23.06.2006, Skvortsov s.n. (MW). Atraphaxis seravschanica Pavlov. UZBEKISTAN. Western Tian-Shan, south spures of the Chatkal Ridge: Angren Ridge, 40 km to NE of Mt Angren, 16.05.1965, Boryaev & Gubanov 43 (MW). Atraphaxis teretifolia (Popov) Kom. KAZAKHSTAN. Karaganda reg. Pribalkhashye: N of the bay Sar-Tchagan, 26.05.1951, Pavlov 333 (MW). Atraphaxis toktogulica (Lazkov) T.M.Schust. & Reveal. KYRGYZSTAN. Toktogul d.: Karajigach, left board of say Tor-Kolot, 5.07.1973, Ajdarova et al. s.n. (LE, holotypus). Atraphaxis tortuosa Losinsk. MONGOLIA occ. The north bank of the river Huang-He, Muni-Ula, ½.05.1872, Przhewalsky s.n. (LE, isotypus). Atraphaxis tournefortii Jaub. & Spach. [IRAN.] Persia, Azerbaijan: 26 km W of Rezaiyeh to Serow, Green Centre, 1600–1700 m a.s.l., 14.06.1971, Lamond 4137 (LE). Atraphaxis virgata (Regel) Krasn. MONGOLIA. Khovd aimag, Dzhungar Goby: 45 km to W of the well Takhi-Us, 30.07.1979, Gubanov 7227 (MW); MONGOLIA. South Goby aimag, Alashan Goby: 5 km to S of the outpost Shuulin, 1.08.1989, Gubanov 198 (MW). Bactria ovczinnikovii (Czukav.) Yurtseva & Mavrodiev. TAJIKISTAN. [Khatlon reg. Shuroabad d.]: the right bank of the river Pyandj. to the north of the village Bog, on gravelly ridges, at the Shpilau river, 1100 m a.s.l., 06.01.1960, fl. and fr., S.Yunusov 1586 (LE); TAJIKISTAN. [Khatlon reg. Shuroabad d.]: the right bank of the river Pyandj, between Bog and Bakhorak, 1100 m a.s.l., 2.06.1960, fl. and fr., S.Yunusov 624 (LE); TAJIKISTAN. Khablon reg., Shuroabad d.: the river Pyandj, Bakhorak × Bag, 25.07.2013, Ukrainskaya et al. 12. (MW); SOUTHERN TAJIKISTAN. [Khatlon reg. Shuroabad d.]: village Bag at the the river Pyandj, red and gray sandstones on the left bank of the Aarzy-Su, 2.06.1960, Botschantzev & Egorova 814 (LE); SOUTHERN TAJIKISTAN. [Khatlon reg. Shuroabad d.]: Schpilau, the river Pyandj, village Bag, 1.06.1960, Nepli s. n. (LE) Polygonum aridum Boiss. [IRAN.] Luristan: Kuh Enhker, in rupestr. frigid., 10000’, Jul. 1868, C. Haussknecht s.n. (LE); [IRAN.] Luristan: M. Sawers, 8000’, Jul. 1868, C. Haussknecht s.n. (LE). Polygonum dumosum Boiss. [IRAN.] Pers. austr.: prope ruinas u. Persepolis 16. Apr. 1842. Th. Kotschy 242 (LE); [IRAN.] Persepolis, Kotschy (LECB, Ex herb. Th. Bienert); [IRAN.] Fars: NW of Takht e Jamshid Kuh Ayub, 30°02’N, 52°38’E, 1800 m a.s.l., 23.05.1959,

192 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL. Wendelbo 790 (LE). Polygonum salicornioides Jaub. & Spach. [IRAN.] Pers. austr., In alpe Kuh-Delu, 10 jun.1842, Th. Kotschy 468, sub Polygonum oligophyllum Boiss. (Ed. R.F.Hohenaker, 1845) (LE 00011673). Polygonum spinosum H.Gross. [IRAN.] Pers. Austr.-orient., prov. Kerman: in jugis alpinis montis Kuh-i-Nasr, 3400–3900 m a.s.l., 24.05.1892, J.Bornmüller 5083, sub P. salicornioides Jaub. & Spach (LE).

Appendix 2. The codes of morphological characters for the standard MP analysis and 3TA.

The character states are: (0)—assumed as a plesiomorphic charater state, (1)—assumed as apomorphic character state, (2)—indicates an alternative apomorphic character state.

Life-history 1. Life history: (0) dwarf robust shrub; (1) dwarf caespitose undershrub; (2) tall undershrub with stout shoots; (3) robust shrub. 2. Annual shoots, diameter: (0) 1.5–3.0 mm; (1) 1.0–1.5 mm. 3. Annual shoots: (0) elongated; (1) elongated and constricted. 4. Annual shoot: (0) lignified, not spiny; (1) herbaceous, died off to the base, (2) lignified, spiny. 5. Position of thyrses: (0) terminal; (1) terminal and lateral, (2) lateral constricted. 6. Surface of annual shoot: (0) velutinous-puberulent, (1) papillose, (2) glabrous. Leaf blade 7. Shape of leaf blade (length/width ratio): (0) L/W> 4, (1) 2< L/W< 4, (2) 1< L/W< 2. 8. Petiole length: (0) 1–2 mm, (1) less than 1 mm, (2) more than 2 mm. 9. Leaf blade margin: (0) revolute, (1) undulate, crenulate, (2) smooth and flat. 10. Leaf blades in thyrses: (0) developed, (1) reduced, (2) absent. Ocrea 11. Ocrea length: (0) 2–4 mm, (1) 5–8 mm, (2) 9–12 mm. 12. Ocrea shape: (0) lanceolate-bilacerate (1) truncate-tubular, later 2–4-lacerate, (2) biaristate, with two subulate lacinulas connected by inciso-serrate middle part. Perianth 13. Outer/inner segments ratio length: (0) 1, (1) 2/3–1/2, (2) ½–1/4. 14. Filiform part of perianth tube: (0) <0.3 mm, (1) 0.3–1.0 mm, (2) > 1 mm. 15. Perianth partition: (0) 9/10–4/5, (1) 2/3–3/4, (2) 2/3–1/2. 16. Perianth consistence: (0) petaloid, not accressent, (1) leafy (2) petaloid, accressent. 17. Shape of perianth segments: (0) broadly elliptical, (1) lanceolate, (2) oblong-elliptical (3) broadly ovate, rotundate, cordate, or reniform. 18. Perianth surface: (0) glabrous with papillate margin, (1) totally papillate, (2) papillae at tube, (3) glabrous. 19. Papillae at tube: (0) absent, (1) linear, (2) conical. 20. Filaments: (0) adnate to the base of perianth receptacle, (1) adnate to the middle part of receptacle, (2) inserted in the top of receptacle. 21. Location of nectar-secreating zone: (0) receptacle, (1) receptacle and the bases of filaments, (2) receptacle and the bases of filaments adaxially. 22. Sporoderm ornamentation: (0) foveolate to foveolate-perforate, (1) microreticulate-foveolate to microreticulate- perforate, (2) foveolate-perforate to perforate, (3) reticulate-perforate to striate-perforate, (4) striate-perforate. Achene 23. Achene / perianth length: (0) >1 (exserted achene), (1) <1 (hidden achene). 24. Achene surface: (0) smooth or smooth-pitted, (1) minutely tuberculate. 25. Styles: (0) free from base, (1) connate at base. 26. Stigmas: (0) mini-capitate, (1) linear, (2) capitate (3) fimbriate-capitate. 27. Merosity: (0) trigonous, (1) lenticular.

Genus Persepolium (Polygonaceae, Polygoneae) Phytotaxa 314 (2) © 2017 Magnolia Press • 193 0 0 0 0 0 27 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 3 3 3 3 26 ? 0 1 1 1 1 ? 2 2 2 2 ? ? 3 3 3 3 3 0 0 0 0 0 25 0 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 24 0 0 1 1 1 1 ? 1 1 1 0 0 0 0 0 0 0 1 1 1 1 1 23 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 4 4 4 4 4 22 0 1 2 2 1 4 ? 3 4 4 4 4 4 4 4 4 4 2 2 2 2 2 21 0 0 1 1 1 1 ? 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 20 0 0 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 s.s. 0 0 0 0 19 0 0 1 1 1 1 1 2 2 2 2 2 0 0 0 0 0 0 3 3 3 3 18 0 0 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 3 Atraphaxis , and 3 3 3 3 17 0 1 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 2 2 2 2 16 0 0 1 1 1 1 1 0 0 0 0 2 2 2 2 2 2 2 Spinescentia 2 2 1 15 2 0 0 1 1 1 1 1 1 1 1 1 2 1 1 1 0 2 2 2 2 2 2 14 0 0 0 0 0 0 0 1 1 1 1 2 1 2 2 1 2 2 subsection 2 2 2 13 2 0 0 0 0 0 0 0 0 0 0 0 0 1 2 2 2 2 2 2 2 2 2 12 0 0 1 1 1 1 1 2 2 2 2 2 2 2 2 0 2 2 Polygonum , 0 1 1 11 0 0 2 0 0 0 0 0 1 1 0 0 0 0 0 0 1 0 2 Bactria 2 2 2 10 2 2 2 0 1 2 2 0 2 2 2 0 0 0 0 1 0 1 2 2 2 2 9 1 1 1 0 0 0 1 0 0 1 2 0 0 0 0 0 0 0 1 0 2 2 8 0 0 0 1 1 1 1 1 0 0 0 2 2 1 0 0 1 0 0 2 2 1 7 2 0 1 0 0 0 0 1 1 2 2 0 0 0 2 2 0 0 1 2 2 2 6 2 0 0 0 0 0 0 0 1 1 1 1 1 1 2 2 1 1 2 1 2 2 5 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 2 0 0 1 0 2 2 4 0 0 0 1 2 1 1 1 1 0 0 1 0 0 2 0 0 1 0 0 1 1 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 2 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 3 3 3 1 3 0 0 1 1 1 1 1 2 0 0 2 2 2 3 3 0 2 3 . Matrix of 27 morphological characters scored for 22 species 3 laetevirens pyrifolia pungens seravschanica ovczinnikovii salicornioides spinosum aridum dumosum khajeh-jamalii toktogulica atraphaxiformis tortuosa ariana badghysi angustifolia spinosa fischeri teretifolia frutescens virgata ...... A A A Taxa Bactria lazkovii B P P P P P A A A A A A A A A A A A A ppendix

194 • Phytotaxa 314 (2) © 2017 Magnolia Press YURTSEVA ET AL.