Research Article
Research Article
Molecular phylogenetic data and seed coat anatomy resolve the generic position of some critical Chenopodioideae (ChenopodiaceaeAmaranthaceae) with reduced perianth segments
expand article infoAlexander P. Sukhorukov, Maya V. Nilova, Anastasiya A. Krinitsina, Maxim A. Zaika, Andrey S. Erst§|, Kelly A. Shepherd
‡ Lomonosov Moscow State University, Moscow, Russia
§ Central Siberian Botanical Garden, Russian Academy of Sciences, Novosibirsk, Russia
| Tomsk State University, Tomsk, Russia
¶ Western Australian Herbarium, Kensington, Australia
Open Access


The former Chenopodium subgen. Blitum and the genus Monolepis (Chenopodioideae) are characterised in part by a reduced (0–4) number of perianth segments. According to recent molecular phylogenetic studies, these groups belong to the reinstated genera Blitum incl. Monolepis (tribe Anserineae) and Oxybasis (tribe Chenopodieae). However, key taxa such as C. antarcticum, C. exsuccum, C. litwinowii, C. foliosum subsp. montanum and Monolepis spathulata were not included and so their phylogenetic position within the Chenopodioideae remained equivocal. These species and additional samples of Blitum asiaticum and B. nuttallianum were incorporated into an expanded phylogenetic study based on nrDNA (ITS region) and cpDNA (trnL-trnF and atpB-rbcL intergenic spacers and rbcL gene). Our analyses confirm the placement of C. exsuccum, C. litwinowii and C. foliosum subsp. montanum within Blitum (currently recognised as Blitum petiolare, B. litwinowii and B. virgatum subsp. montanum, respectively); additionally, C. antarcticum, currently known as Oxybasis antarctica, is also placed within Blitum (reinstated here as B. antarcticum). Congruent with previous studies, two of the three accepted species of Monolepis – the type species M. trifida (= M. nuttalliana) as well as M. asiatica – are included in Blitum. The monotypic genus Carocarpidium described recently with the type C. californicum is not accepted as it is placed within Blitum (reinstated here as B. californicum). To date, few reliable morphological characters have been proposed that consistently distinguish Blitum (incl. two Monolepis species) from morphologically similar Oxybasis; however, two key differences are evident: (1) the presence of long-petiolate rosulate leaves in Blitum vs. their absence in Oxybasis and (2) a seed coat structure with the outer wall of the testa cells lacking stalactites (‘non-stalactite seed coat’) but with an obvious protoplast in Blitum vs. seed coat with the outer walls of the testa cells having stalactites (‘stalactite seed coat’) and a reduced protoplast in Oxybasis. Surprisingly, the newly sequenced North American Monolepis spathulata nested within the tribe Dysphanieae (based on ITS and trnL-trnF + rbcL + atpB-rbcL analyses).The phylogenetic results, as well as presence of the stalactites in the outer cell walls of the testa and lack of the rosulate leaves, confirm the distinctive nature of Monolepis spathulata from all Blitum and, therefore, the recent combination Blitum spathulatum cannot be accepted. Indeed, the morphological and molecular distinctive nature of this species from all Dysphanieae supports its recognition as a new monotypic genus, named herein as Neomonolepis (type species: N. spathulata). The basionym name Monolepis spathulata is also lectotypified on a specimen currently lodged at GH. Finally, while Micromonolepis pusilla is confirmed as belonging to the tribe Chenopodieae, its position is not fully resolved. As this monotypic genus is morphologically divergent from Chenopodium, it is retained as distinct but it is acknowledged that further work is required to confirm its status.


Blitum , Chenopodioideae , Chenopodium , Oxybasis , new genus, taxonomy


The family Chenopodiaceae Vent. comprises ~1500 species distributed worldwide (Sukhorukov 2014). It is divided into several subfamilies and at least one third of them belong to the core subfamily Chenopodioideae in the tribes Axyrideae G.Kadereit & Sukhor. (Axyris L., Ceratocarpus L., Krascheninnikovia Gueldenst.), Chenopodieae incl. Atripliceae Duby (Archiatriplex G.L.Chu, Atriplex L., Chenopodiastrum S.Fuentes, Uotila & Borsch, Chenopodium L. s.str., Exomis Fenzl ex Moq., Extriplex E.H.Zacharias, Grayia Hook. & Arn., Halimione Aellen, Holmbergia Hicken, Lipandra Moq., Manochlamys Aellen, Microgynoecium Hook.f., Micromonolepis Ulbrich, Oxybasis Kar. & Kir., Proatriplex Stutz & G.L.Chu and Stutzia E.H.Zacharias), Anserineae (Blitum L. incl. Scleroblitum Ulbr., Spinacia L.) and Dysphanieae (Cycloloma Moq., Dysphania R.Br., Suckleya A.Gray and Teloxys Moq.) (Kadereit et al. 2003, 2010; Zacharias and Baldwin 2010; Fuentes-Bazan et al. 2012a, 2012b). While tribal boundaries are becoming well established, the status of a number of genera is far from stabilised, as ongoing molecular phylogenetic analyses continue to highlight new and sometimes unexpected relationships.

Some of the most recent and drastic taxonomic changes have been proposed by Fuentes-Bazan et al. (2012b) following their phylogenetic study of the large genus Chenopodium (~200–250 species) (Fuentes-Bazan et al. 2012a) and this classification is currently accepted by many authors (e.g. Iamonico 2011, 2014; Mosyakin 2013; Uotila 2017; Sukhorukov et al. 2013; Sukhorukov and Kushunina 2014, Hernández-Ledesma et al. 2015; Mosyakin and Iamonico 2017). According to the findings by Fuentes-Bazan et al. (2012b), Chenopodiumsensu lato was shown to be polyphyletic and members previously included in the genus are now placed in tribes Chenopodieae incl. Atripliceae (Chenopodium s.str. 100–150 spp., Oxybasis ~12 spp., Chenopodiastrum 8–9 spp., Lipandra Moq., 1 sp.), Dysphanieae (Dysphania >50 spp., Teloxys 1 sp.) and Anserineae (Blitum ~12 spp.). To accomplish this, they reinstated the genera Oxybasis (type species O. minutiflora Kar. & Kir. = O. chenopodioides (L.) S.Fuentes, Uotila & Borsch) and Lipandra (type species L. polysperma (L.) Moq. ≡ Chenopodium polyspermum L.) and recognised the new genus Chenopodiastrum S.Fuentes, Uotila & Borsch. Finally, two of three known species of the genus Monolepis Schrad. included in the study (the type species M. trifida (Trev.) Schrad. = M. nuttalliana (Schult.) Greene) as well as M. asiatica Fisch. & C.A.Mey.) were shown to be nested within Blitum based on ITS (nrDNA) and trnF intergenic spacer with moderate statistical support (Fuentes-Bazan et al. (2012a). As Blitum is the oldest available name (Linnaeus 1753), Monolepis asiatica was transferred and M. nuttalliana was re-instated as Blitum asiaticum (Fisch. & C.A.Mey.) Fuentes et al. and B. nuttallianum Schult., respectively (Fuentes-Bazan et al. 2012b). The third Monolepis species, M. spathulata A.Gray, was not sequenced, but also transferred into Blitum [as B. spathulatum (A.Gray) Fuentes et al.] due to its morphological similarity to both B. asiaticum and B. nuttallianum.

Further changes were subsequently proposed by Theodorova (2014), provided without a detailed explanation, suggesting that Blitum should be expanded to include Lipandra, Oxybasis and Chenopodiastrum, resulting in the proposed new combinations Blitum urbicum (L.) T.A.Theodorova (≡ Oxybasis urbica (L.) S.Fuentes, Uotila & Borsch), B. polyspermum (L.) T.A.Theodorova (≡ Lipandra polysperma (L.) S.Fuentes, Uotila & Borsch) and B. hybridum (L.) T.A.Theodorova (≡ Chenopodiastrum hybridum (L.) S.Fuentes, Uotila & Borsch). Recently, Zhu and Sanderson (2017) described a new monotypic genus Carocarpidium S.C.Sanderson et C.L.Chu with the type species C. californicum (S.Wats.) S.C.Sanderson & G.L.Chu (≡ Blitum californicum S.Wats. ≡ Chenopodium californicum (S.Wats.) S.Wats.), based on the fruits having a fleshy pericarp.

The recent split of Chenopodiumsensu lato into genera belonging to different tribes as suggested by Fuentes-Bazan et al. (2012b) is supported in part by morphological characters. First, all species of Chenopodium with obvious glandular hairs, ovoid or roundish, yellow or orange subsessile glands and simple hairs now belong to the tribe Dysphanieae (placed in either Dysphania R.Br. or Teloxys Moq.), while the remaining former Chenopodium (now included in Chenopodieae and Anserineae) have an indumentum of white bladder (“mealy”) hairs, sometimes with scattered simple hairs (Reimann and Breckle 1988; Simón 1997; Sukhorukov et al. 2015b). The number of perianth segments was also traditionally thought to be a good diagnostic character, which usually corresponds to the number of stamens. Chenopodium s.str., Lipandra and Chenopodiastrum are characterised by the presence of five perianth segments and five stamens, while various genera across the subfamily are characterised by a lower number (1–4) of perianth segments and stamens, as observed in some Oxybasis and Micromonolepis (Chenopodieae), Blitum incl. Monolepis (Anserineae) and many Dysphania (Dysphanieae), especially amongst Australian species (e.g. Ulbrich 1934; Wilson 1984; Judd and Ferguson 1999; Holmgren 2003). However, this character may not be consistently informative as species such as Oxybasis urbica usually has 5 perianth segments and 5 stamens.

It has become apparent in recent years that fruit and seed characters are also useful in distinguishing members of the former Chenopodium, particularly amongst groups that are quite morphologically similar (Sukhorukov 2006, 2014; Sukhorukov and Zhang 2013; Sukhorukov et al. 2015a). A good example is Chenopodium gubanovii Sukhor. Originally this species was described as a member of the former Chenopodium subgen. Blitum sect. Pseudoblitum (Sukhorukov 1999). Its generic status was discussed by Fuentes-Bazan et al. (2012b) and finally resolved by Sukhorukov et al. (2013) as being a part of Oxybasis [Oxybasis gubanovii (Sukhor.) Sukhor. et Uotila] based on molecular phylogenetic data supported by morphological and seed characters. Almost all Chenopodieae (Archiatriplex, Chenopodium, Chenopodiastrum, Exomis, Holmbergia, Lipandra, Manochlamys, Microgynoecium, Proatriplex and all Atriplex with red or black seeds) possess a seed-coat testa with thickened outer cell walls impregnated with vertical or oblique stalactites and a reduced protoplast (hereafter ‘stalactite seed coat’) (Sukhorukov 2006; Kadereit et al. 2010; Sukhorukov and Zhang 2013; Sukhorukov 2014). There are a few exceptions, however, for example the seed coat in Halimione and three Chenopodium species endemic to Juan Fernández Archipelago (Chile) (C. nesodendron Skottsb., C. sanctae-clarae Johow, C. sancti-ambrosii Skottsb.), does not contain the stalactites in the outer cell walls and possesses a visible protoplast (hereafter ‘non-stalactite seed coat’) (Sukhorukov 2014). These three geographically isolated Chilean species are closely allied and highly unusual, as they not only possess a non-stalactite seed coat but have a tree-like habit and fruits with an apically swollen pericarp. Of these, only C. sanctae-clarae has been included in molecular analyses (Kadereit et al. 2010), which confirmed its phylogenetic position within this genus. The non-stalactite seed coat morphology is also evident in the Dysphanieae, Chenopodium antarcticum Hook.f [≡ Oxybasis antarctica (Hook.f.) Mosyakin], almost all Blitum sensu Fuentes-Bazan et al. (2012b) with the exception of Blitum spathulatum (A.Gray) S.Fuentes, Uotila & Borsch, or Monolepis spathulata (Sukhorukov 2014).

Amongst the species of the former Chenopodium or Monolepis investigated carpologically but not included in recent molecular phylogenetic studies, two taxa are of special interest. The first, Monolepis spathulata, is endemic to western states of USA and North Mexico and was transferred to Blitum (as B. spathulatum) due to morphological affinities with other species of the genus. The second taxon, Chenopodium antarcticum, is another poorly known taxon endemic to Tierra del Fuego (southernmost parts of Argentina and Chile) that still occupies a pending position within Chenopodioideae. Previously, it was described as Blitum antarcticum Hook.f. (Hooker 1847) and later transferred by the same author to Chenopodium as C. antarcticum (Hook.f.) Hook.f. (Bentham and Hooker 1880). The latter name was widely accepted in subsequent taxonomic treatments (Reiche 1911; Aellen 1929, 1931; Aellen and Just 1943; Moore 1983; Giusti 1984; Zuloaga and Morrone 1999). Recently, Chenopodium antarcticum was transferred into Oxybasis by Mosyakin [2013, as O. antarctica (Hook.f.) Mosyakin] based on its morphological similarity to other Oxybasis. However, the stalactite seed coat morphology of Blitum spathulatum and non-stalactite seed coat of Oxybasis antarctica contrast with those of other members of Blitum and Oxybasis, respectively (Sukhorukov 2014), which raises the question of their true phylogenetic position.

To resolve this issue, we have included these two species, in addition to several accessions of taxa sampled for the first time [Chenopodium antarcticum, C. exsuccum (C.Loscos) Uotila, C. litwinowii (Paulsen) Uotila, C. foliosum (Moench) Asch. subsp. montanum Uotila and Monolepis spathulata], as well as an additional sample of Blitum asiaticum (Fisch. & C.A.Mey.) S.Fuentes, Uotila & Borsch. in expanded molecular analyses based on nrDNA (ITS region) and cpDNA (atpB-rbcL intergenic spacers + rbcL and trnL-trnF intergenic spacer + rbcL, hereafter as atpB-rbcL and trnL-trnF, respectively) to determine their phylogenetic position within the Chenopodioideae. Furthermore, we discuss the role of fruit and seed characters for delimitating morphologically similar but phylogenetically distant taxa and conclude with proposed taxonomic changes that reflect our findings.


Taxon sampling

Several new taxa were included in the phylogenetic analysis for the first time: Chenopodium antarcticum (Hook.f.) Hook.f. [≡ Oxybasis antarctica (Hook.f.) Mosyakin: Chile, Tierra del Fuego, December 1971, Moore & Goodall s.n. (LE)]; C. exsuccum (C.Loscos) Uotila: Algeria, Zenina, July 1968, V.P. Boczantsev 681 (LE); C. foliosum (Moench) Asch. subsp. montanum Uotila: Iran, prov. Tehran, Elburz, June 1977, K.-H. Rechinger 57243 (B); C. litwinowii (Paulsen) Uotila: Afghanistan, Parwan prov., Salang, 8 August 1969, J.E. Carter 602 (LE); Monolepis spathulata A.Gray: USA, California, Susanville, August 1983, I.Yu. Koropachinsky & al. 404 as Monolepis nuttalliana (MHA). Additionally, we have included a new accession of Blitum asiaticum (Fisch. et C.A.Mey.) S.Fuentes, Uotila et Borsch (Russia, Yakutiya, Ust-Yansky distr., August 1976, E.V. Ter-Grigoryan 1009, MHA). The taxa included in the molecular analyses and their GenBank accession numbers are given in the Table 1.

Table 1.

Voucher information and GenBank accession numbers for the species of Chenopodioideae and outgroups included in the phylogenetic analysis (arranged in alphabetical order). The newly sequenced samples are highlighted in bold. Some vouchers in GenBank may be stored under old names.

Species Old names (if applicable) GenBank accession number
ITS rbcL trnL-trnF atpB-rbcL
Atriplex hortensis HM005854 KX678160 HE577500
Atriplex patula HE577358 MG249776 HE577498 HM587650
Atriplex spongiosa AY270060 HM587661
Atriplex undulata AY270061 HM587665
Atriplex phyllostegia HM005870 HM587590 HM587651
Atriplex peruviana HM005867
Atriplex watsonii HM005871
Atriplex rusbyi HM005865
Atriplex patagonica HM587541
Atriplex lentiformis HM005872 HM587637
Atriplex cinerea HM587491
Atriplex centralasiatica DQ086481 HM587583 HM587621
Atriplex suberecta HM005863
Axyris amaranthoides AM849227 KX678411 HE577510
Axyris hybrida HE577371 HE577511
Blitum antarcticum Chenopodium antarcticum (Oxybasis antarctica) MH155315 MH632743 MH632745 MH152573
Blitum asiaticum Monolepis asiatica MH150882 MH731231 MH731229
Blitum bonus-henricus Chenopodium bonus-henricus HE577372 KF613023 HE577512 HM587670
Blitum californicum Chenopodium californicum HE577376 MF963177 HE577516
Blitum capitatum Chenopodium capitatum KJ629064 MG249277 HE577513
Blitum litwinowii Chenopodium litwinowii MH153781 MH632744 MH632746 MH632749
Blitum nuttallianum Monolepis nuttalliana HE577375 JX848452 HE577515 HM587702
Blitum petiolare Chenopodium exsuccum MH150883 MH632747 MH152574
Blitum virgatum L. Chenopodium foliosum JF976147 AY270081 HE577518 HM587673
Blitum virgatum subsp. montanum Chenopodium foliosum subsp. montanum MH155242
Ceratocarpus arenarius AY556430 HM587594 HE577505
Chenopodiastrum coronopus Chenopodium coronopus HE577403 HM587595 HE577543 HM587671
Chenopodiastrum hybridum Chenopodium hybridum HE577530 HE577530
Chenopodiastrum murale Chenopodium murale HE577392 HM849890 HE577531 HM587675
Chenopodium album JF976146 JF941270 HE577609 MF073794
Chenopodium atrovirens KP226648 / KX679232 HE577587
Chenopodium auricomum KP226671
Chenopodium bengalense Chenopodium giganteum HE577458
Chenopodium berlandieri var. boscianum HE577426 MG249740 HE577564
Chenopodium berlandieri var. zschackei HE577425
Chenopodium desertorum HE577417 AY270042 HE577555 HM587672
Chenopodium desiccatum HE577412 KX678128 HE577550
Chenopodium ficifolium HE577466 KM360714 HE577606
Chenopodium fremontii HE577408 KX679065 HE577572
Chenopodium hians HE577470 MG248000 HE577610
Chenopodium iljinii HE577468
Chenopodium incanum HE577410 MG246401 HE577548
Chenopodium leptophyllum HE577428 MG248863 HE577566
Chenopodium neomexicanum KJ629054
Chenopodium nevadense HE577411
Chenopodium opulifolium HE577454 MG248036 HE577594
Chenopodium pallescens HE577409
Chenopodium pallidicaule KJ629055
Chenopodium nutans Einadia nutans KM896090 HM587686
Chenopodium parabolicum Rhagodia parabolica KU564859 HM587704
Chenopodium quinoa HE577443 KY419706 KY419706
Chenopodium standleyanum KJ629051 MG249838 HE577560
Chenopodium subglabrum HE577465 MG249459 HE577605
Chenopodium vulvaria HE577407 JN892907 HE577591
Chenopodium watsonii HE577462 MG246238 HE577602
Cycloloma atriplicifolium HQ218998 HM587598 HM587681
Dysphania ambrosioides Chenopodium ambrosioides DQ005963 MG249540 HE577493 HM587682
Dysphania botrys Chenopodium botrys KJ629068 MG247946 DQ499383 HM587683
Dysphania cristata Chenopodium cristatum KJ629066 AY270046 HM587684
Dysphania glomulifera Chenopodium glomuliferum AY270086 HM587685
Dysphania pumilio Chenopodium pumilio HE577343 MG248652 HE577485
Dysphania schraderiana Chenopodium schraderianum HE577349
Exomis microphylla HM587601 HM587687
Grayia brandegeei HM005845 HM587604 HE577497 HM587690
Grayia spinosa HM005844 HM587605 HE577496 HM587691
Halimione verrucifera Atriplex verrucifera HM587575 HM587606 HM587695
Halimione pedunculata Atriplex pedunculata HM587573 AY270093 HM587694
Holmbergia tweedii HM005842 AY270100 HM587696
Krascheninnikovia ceratoides HE577367 AY270105 HE577507 HM587697
Krascheninnikovia ceratoides subsp. lanata Krascheninnikovia lanata HE577368 MG248963 HE577508 HM587698
Lipandra polysperma Chenopodium polyspermum KJ629061 KX677934 HE855686
Micromonolepis pusilla HM587608 HM587701
Neomonolepis spathulata Monolepis spathulata (Blitum spathulatum) MH675518 MH731232 MH731230 MH152575
Oxybasis glauca Chenopodium glaucum KJ629060 MG249300 HE577527 MF073807
Oxybasis rubra Chenopodium rubrum HE577381 MG249329 HE577525
Oxybasis urbica Chenopodium urbicum KJ629057 MG246691 HE577524 HM587678
Oxybasis micrantha KU359325
Spinacia oleracea EU606218 AJ400848
Suckleya suckleyana HE577347
Teloxys aristata Chenopodium aristatum; Dysphania aristata KJ629070 AY270140 HM587708
Bassia laniflora Kochia laniflora KF785942
Bassia prostrata Kochia prostrata KF785963 AY270104 HE577478 KF785926
Beta vulgaris AY858597 DQ074969
Hablitzia tamnoides AY858590 AY270092 HE577475 JQ407841
Polygonum aviculare MF158792 HQ843161 JN234937
Polygonum aviculare subsp. buxiforme GQ339988

DNA extraction

Total genomic DNA was extracted from herbarium samples according to Krinitsina et al. (2015). Following the homogenisation of plant fragments (MiniLys, Bertin Technologies, France), total DNA was extracted using the CTAB-method (Doyle and Doyle 1987) and further purified using AMPure Beads (Beckman Coulter, USA).

PCRs for two chloroplast markers (atpB-rbcL and trnL-trnF) and nrDNA (ITS region) were carried out in a Thermal Cycler T100 (Bio-Rad, USA) using primers and cycler programmes listed in Table 2. A 10 ng aliquot of DNA was used to make a 25 μl total volume reaction, containing 1 μM of each primer, 200 μM of each dNTP and 0.5 U Encyclo polymerases (Evrogen, Russia). PCR products were checked on 1.2% agarose gels and purified using AMPure Beads (Beckman Coulter, USA) according to the owner’s manual. AMPure Beads suspension was mixed with a solution containing PCR-product ratio 1 vol. PCR-mix: 1.2 vol. AMPure Beads for atpB-rbcL and ITS primer pairs and 1 vol. PCR-mix: 1.4 vol. AMPure Beads for rbcL, Tab C/Tab D and Tab E/Tab F primer pairs.

Table 2.

Primers and cycler programmes used for the molecular analysis.

Marker Primer sequences and combination Reference Cycler programmer
ITS ITS5 5'-GGA AGT AAA AGT CGT AAC AAG G-3' White et al. (1990) 95 °C for 5 min, 33 cycles of amplification (95 °C for 15 s, 55 °C for 30 s, 72 °C for 40 s), 72 °C for 5 min
rbcL (partial) rbcLaF 5'- ATG TCA CCA CAA ACA GAG ACT AAA GC-3' Levin et al. (2003) 95 °C for 5 min, 35 cycles of amplification (95 °C for 10 s, 55 °C for 30 s, 72 °C for 40 s), 72 °C for 5 min
rbcLaR 5'-GTA AAA TCA AGT CCA CCR CG-3' Kress et al. (2009)
atpB-rbcL spacer atpB-rbcL F 5'-GAA GTA GTA GGA TTG ATT CTC-3' Golenberg et al. (1993) 95 °C for 5 min, 35 cycles of amplification (95 °C for 20 s, 56 °C for 30 s, 72 °C for 60 s), 95 °C for 20 s, 56 °C for 80 s, 72 °C for 8 min
trnL-F Tab C 5'-CGA AAT CGG TAG ACG CTA CG-3' Taberlet et al. (1991) 95 °C for 5 min, 35 cycles of amplification (95 C for 1 min, 50 °C – 65 °C (increasing in 0.3 C per cycle) for 1 min, 72 °C for 4 min), 72 °C for 5 min

Sequencing and alignment

Sequencing was performed following Sanger methods on an Applied Biosystems 3730 DNA Analyser using ABI PRISM BigDye Terminator v. 3.1 (Center of Collective Use “Genome”, Institute of Molecular Biology, Moscow, Russia). The sequencing primers were the same as the amplification primers.

The raw forward and reverse sequences were checked and combined in BioEdit sequence alignment editor v. (Hall 1999). Sequences were edited and aligned using Muscle 3.6 (Edgar 2004). The obtained alignments were manually edited using PhyDe (version 0.9971: Müller et al. 2010) following the rules outlined in Löhne and Borsch (2005). Mutational hotspots (regions of uncertain homology) were excluded from the analysis (Borsch et al. 2003). Gaps were treated as missing data during the phylogenetic inference.

Phylogenetic inference

To show the relationships between taxa, we reconstructed various phylogenies using Bayesian analysis, maximum likelihood (ML) and maximum parsimony (MP) methods for the ITS and combined trnL-trnF + rbcL + atpB-rbcL datasets. Models of nucleotide substitution were selected using the MrModeltest 2.1.7 (Nylander 2004) via the Akaike information criterion (AIC: Akaike 1974). The substitution model was set to GTR + G + I. For the ML analyses, we employed RAxML Version 8 (Stamatakis 2014). Bootstrap analyses were conducted with 2500 replicates for ML. Parsimony analyses were conducted in PAUP* 4.0a162 (Swofford 2002) with the following settings: all characters have equal weight, MaxTrees set to 1000 (auto increased by 1000), TBR branch swapping and with 20000 jackknife (JK) replicates to calculate node support. Bayesian analyses were conducted in BEAST 2.5.0 (Bouckaert et al. 2014). Four Markov Chain Monte Carlo analyses with four chains were run for 20 million generations for every dataset, sampling every 1000 generations. Burn-in was set to remove 5% of the total trees sampled after assessing likelihood convergence by inspection of the trace plots in the programme Tracer v.1.6 (Rambaut et al. 2014). A birth and death prior was chosen for branch lengths (Gernhard 2008). The maximum clade credibility tree was calculated in the programme TreeAnnotator v1.4.8 (Drummond and Rambaut 2007) with a posterior probability limit of 0.7. Final trees were edited in the programme TreeGraph ver. 2.14.0 (Stöver and Müller 2010).

Morphology and anatomy

The carpology of the tribe Chenopodioideae was described in detail in a previous study by Sukhorukov (2014). In this study, we pay particular attention to the fruit and seed of Chenopodium antarcticum and to the general structure of the reproductive shoot of Monolepis spathulata that were not illustrated in Sukhorukov (2014). The samples were observed using a scanning electron microscope (SEM) JSM–6380 (JEOL Ltd., Japan) at 15 kV after sputter coating with gold-palladium in the laboratory of Electron Microscopy at Lomonosov Moscow State University. Prior to SEM, the fruits were dehydrated in aqueous ethyl alcohol solutions of increasing concentration, followed by alcohol-acetone solutions and pure acetone. No dehydration of the seeds is required prior to SEM observation due to the absence of soft tissues (e.g. papillae or trichomes) on their surface.

The cross-sections of the seeds were prepared using a rotary microtome Microm HM 355S (Thermo Fisher Scientific, USA) and then examined using a Nikon Eclipse Ci (Nikon Corporation, Japan) light microscope and photographed using a Nikon DS-Vi1 camera (Nikon Corporation, Japan) at the Department of Higher Plants, Lomonosov Moscow State University. Before sectioning, the seeds were soaked in water:alcohol:glycerine (1:1:1) solution, dehydrated in ethanol dilution series and embedded in the Technovit 7100 resin (Heraeus Kulzer, Germany).


Phylogenetic analysis

The phylogenetic analysis based on nrDNA (ITS) and combined cpDNA analyses (trnL-trnF + rbcL + atpB-rbcL) revealed that the tribes Axyrideae, Chenopodieae s.str., Anserineae and Dysphanieae are well-supported within Chenopodioideae and congruent with previous molecular analyses by Fuentes-Bazan et al. (2012b) (Figures 12). The results outlined below focus on the phylogenetic position of the newly included taxa Chenopodium antarcticum [≡ Oxybasis antarctica], C. litwinowii, C. exsuccum, C. foliosum subsp. montanum and Monolepis spathulata.

Figure 1. 

Best tree from the BEAST analysis of the ITS Chenopodioideae dataset. Bayesian posterior probabilities are given above the branches, jackknife values (left) and bootstrap percentages of the maximum likelihood analyses (right) are given below branches.

In the ITS analysis (Figure 1), the tribe Axyrideae is placed sister to the remaining Chenopodioideae. The next diverging lineage is a well-supported Dysphanieae, with Monolepis spathulata + Teloxys forming a sister lineage to the remaining representatives of the tribe. Chenopodium antarcticum, C. litwinowii, C. exsuccum and C. foliosum subsp. montanum fall well within Blitum, which is sister to a well-supported Chenopodieae. Blitum californicum and B. bonus-henricus (L.) C.A.Mey. form part of the polytomy with the rest of the genus.

Like the ITS phylogenetic analysis, the combined trnL-trnF + rbcL + atpB-rbcL tree (Figure 2) shows the Axyrideae as an early branching lineage in Chenopodioideae, sister to a polytomy of Dysphanieae, Anserineae and Chenopodieae. Within the Dysphanieae, Monolepis spathulata and Teloxys form a polytomy with the remaining representatives of the tribe, which includes Cycloloma nested within Dysphania. Chenopodium antarcticum, C. litwinowii and C. exsuccum are nested within Blitum (C. foliosum subsp. montanum is not included in the combined tree). Chenopodium antarcticum is sister to Chenopodium exsuccum + C. litwinowiiBlitum virgatum.

Figure 2. 

Best tree from the BEAST analysis of the combined trnL-trnF + rbcL + atpB-rbcLChenopodioideae dataset. Bayesian posterior probabilities are given above the branches, jackknife values (left) and bootstrap percentages of the maximum likelihood analyses (right) are given below branches.

Carpological studies

This study highlighted the fact that these species, with the exception of Monolepis spathulata, possess the same fruit and seed anatomy as other Blitum species such as a mamillate pericarp (Figure 3) and non-stalactite seed-coat with obvious (visible) protoplast (Table 3; Figure 4). In contrast, the carpology of Monolepis spathulata somewhat resembles the morphology observed in species of Oxybasis and many other Chenopodieae in having a papillate pericarp and a stalactite seed coat with a highly reduced protoplast (Figure 5). Other important characters such as life history, the degree of fusion of reduced perianth segments, pericarp structure and adherence, the colour, shape and morphology of seeds and an embryo position, are recorded for representative species of each genus, as summarised in Table 3.

Figure 3. 

Pericarp of Blitum antarcticum. Scale bar: 200 μm.

Figure 4. 

Cross-section of the seed of Blitum antarcticum. Abbreviations: T – testa, TE- tegmen, PE – perisperm.

Figure 5. 

Cross-section of the seed of Neomonolepis spathulata. Abbreviations: T – testa, TE – tegmen, PE – perisperm, ST – stalactites in the outer walls of the testa cells.

Table 3.

Additional noteworthy characters evolved in Blitum and Oxybasis. This table summarises life history and carpological data from Sukhorukov and Zhang (2013), Sukhorukov et al. (2013), Sukhorukov (2014), with additional information included for Blitum virgatum subsp. montanum and B. korshinskyi.

Taxon/Character Life history Perianth segments Cells of the outer pericarp layer Pericarp adherence to the seed coat Seed shape and colour Seed surface Seed keel Thickness of seed-coat testa (µm) Acicular outgrowths of the testa cells Presence of spatial heterospermy Seed embryo position
Blitum antarcticum short-lived perennial herb basally connate spongy scraped off the seed roundish, red alveolate 12–20 vertical
B. asiaticum annual free not spongy easily ruptured roundish, red undulate + 7–10 vertical
B. atriplicinum annual or short-lived perennial herb basally connate not spongy hardly removed roundish, red alveolate, with hairy-like outgrowths 17–25 + vertical
B. bonus-henricus perennial herb basally connate spongy scraped off the seed roundish, red smooth 37–45 + vertical, rarely horizontal
B. californicum perennial herb basally connate spongy scraped off the seed roundish, red alveolate 25–30 and 37–45 (heterospermous) + vertical
B. capitatum annual or short-lived perennial herb basally connate not spongy hardly removed ovate, red undulate + (two keels and a groove between them) 12–15 + vertical
B. hastatum annual or short-lived perennial herb connate to 1/3 not spongy hardly removed ovate, red undulate + (two keels and a groove between them 15–18 + vertical
B. korshinskyi annual or short-lived perennial herb almost free not spongy hardly removed ovate, red undulate + (two keels and a groove between them) 10–12 vertical
B. litwinowii annual or short-lived perennial herb basally connate not spongy hardly removed ovate, red alveolate + (two keels and a groove between them) 10–12 vertical
B. nuttallianum annual free, or perianth absent not spongy hardly removed roundish, red alveolate, with hairy-like outgrowths 8–10 + vertical
B. petiolare annual or short-lived perennial herb basally connate not spongy hardly removed ovate, red alveolate + (two keels and a groove between them) 15–17 vertical
B. virgatum annual or short-lived perennial herb basally connate not spongy hardly removed ovate, red undulate + (two keels and a groove between them) 10–12 + vertical
Oxybasis chenopodioides annual fused in almost all flowers, free only in some flowers not spongy easily ruptured roundish, red minutely pitted 10–15 + vertical and horizontal
O. glauca annual basally connate not spongy easily ruptured roundish, red minutely pitted 10–15 and 17–25 (heterospermous) + + vertical and horizontal
O. gubanovii annual basally connate not spongy hardly removed roundish, red smooth (minutely pitted) + (one keel) 12–15 + vertical
O. macrosperma annual connate to the middle or almost to the top spongy scraped off the seed roundish, red reticulate with minutely pitted dots 12–20 + vertical and horizontal
O. mexicana annual basally connate not spongy easily ruptured roundish, red reticulate with minutely pitted dots 20–25 + + vertical and horizontal
O. micrantha annual basally connate not spongy scraped off the seed roundish, red minutely pitted + (one keel) 12–15 + horizontal, rarely vertical
O. rubra annual basally connate not spongy easily ruptured roundish, red reticulate with minutely pitted dots 10–15 + vertical and horizontal
O. urbica annual basally connate papillate scraped off the seed roundish, black minutely pitted 42–50 + horizontal


The phylogenetic position of Chenopodium foliosum subsp. montanum [≡ Blitum virgatum L. subsp. montanum (Uotila) S.Fuentes, Uotila et Borsch], C. exsuccum [= Blitum petiolare Link] and C. litwinowii [≡ B. litwinowii S.Fuentes, Uotila et Borsch] within Blitum as proposed by Fuentes-Bazan et al. (2012b) was supported by the findings of this study. Indeed, the results were predictable due to the shared morphological and carpological affinities of these species to B. virgatum, such as the presence of a leaf rosette, tight adherence of the pericarp to the seed coat and the ovoid and keeled seeds having the same anatomical structure (e.g. Uotila 1993, 1997; Sukhorukov 2014). For this reason, while Chenopodium korshinskyi (Litv.) Minkw. has not been included in any molecular phylogenies to date, it should be treated as Blitum korshinskyi Litv. (Fuentes-Bazan et al. 2012b) due to the shared presence of these diagnostic traits. It is also evident, based on phylogenetic and carpological data from this study, that Oxybasis antarctica (formerly Chenopodium antarcticum) must be treated as Blitum antarcticum as proposed by Hooker (1847). Moreover, as Oxybasis antarctica is the type of Oxybasis sect. Thellungia (Aellen) Mosyakin [including Oxybasis antarctica and O. erosa (R.Br.) Mosyakin: Mosyakin 2013], this section may be recognised within Blitum but this requires further exploration as the phylogenetic position of B. antarcticum remains equivocal.

Diagnostic characters for Blitum and Oxybasis

The importance of morphological characters used to delineate species within the genus Chenopodium that are now considered to belong to either Blitum or Oxybasis have been discussed by various authors (e.g. Moquin-Tandon 1840, 1849; Aellen and Just 1943; Scott 1978; Fuentes-Bazan et al. 2012b). However, the morphological similarity of some species has led to taxonomic confusion. For example, many macromorphological characters overlap in Blitum and Oxybasis, including previous diagnostic traits such as: reduced (1–4) number of perianth segments, presence of the vertical seed embryo position and emergence of spatial heterospermy. Such characters are clearly homoplastic in Chenopodieae, Anserineae and some other groups of the Chenopodioideae (Sukhorukov and Zhang 2013). Only one trait visible to the naked eye, the presence of leaf rosette in Blitum (Figure 6) and its absence in Oxybasis, can be used for the delimitation of both genera (see diagnostic key and generic descriptions in Fuentes-Bazan et al. 2012b). However, it should be noted that the leaf rosette in some Blitum, especially in species previously included in Monolepis (B. asiaticum, B. nuttallianum), is reduced to 1–2 leaves that may wither away completely by anthesis. From this study and from previous work (Sukhorukov and Zhang 2013; Sukhorukov et al. 2013; Sukhorukov 2014), it is evident that another character, the structure of the testa cells of the seed coat, is also diagnostic. In Oxybasis, as well as almost all other Chenopodieae, the seed testa cells have a reduced protoplast and “stalactites” hanging vertically in the outer wall (stalactite seed coat). In contrast, the presence of non-stalactite seed coat with a highly visible protoplast, unambiguously distinguishes Blitum. Other characters, such as reduced perianth segments, mamillate pericarp, red seeds, seed keel, vertical embryo position of note for representative species of each genus, are summarised in Table 3 and they play a role for the diagnostics at the species level or species group (see Sukhorukov 2014 for further detail).

Figure 6. 

Habit of Blitum asiaticum showing the senescing leaf rosette. Photographer: Igor Pospelov (Russia, Krasnoyarsk prov., Taymyr, Khatanga, August 2014).

In the absence of molecular phylogenetic data, it is clear that carpological characters must be taken into consideration when determining the generic placement of taxa in either Blitum or Oxybasis. Molecular data from this study and previous investigations (Kadereit et al. 2010; Fuentes-Bazan et al. 2012a, 2012b), when examined in conjunction with carpological evidence (Sukhorukov 2014), show that two taxonomic changes recently proposed: (1) the merger of Oxybasis, Lipandra and Chenopodiastrum (Chenopodieae) into an extended Blitum (Anserineae) as suggested by Theodorova (2014) and (2) the description of a new monotypic genus Carocarpidium S.C.Sanderson et G.L.Chu with the type C. californicum (≡Blitum californicum) by Zhu and Sanderson (2017), cannot be accepted. Additionally, it should be noted that the pericarp of B. californicum is not fleshy as previously described (Zhu and Sanderson 2017), but its outer layer consists of spongy (mamillate) cells that imitate a “fleshy” pericarp. This type of mamillate pericarp is present in some Blitum and Oxybasis (Figure 3, see also Table 3) and so this character is clearly not unique to Carocarpidium.

Micromonolepis pusilla

This species was initially described as Monolepis pusilla Torr. ex Watson (Watson 1871) and it is noteworthy to consider its morphology and phylogenetic position in context with other species previously known as Monolepis. It is a small annual herb covered with bladder hairs that has fleshy leaves (Figure 7), unisexual flowers with reduced (1–3) perianth segments and tiny papillate fruits. Due to its unusual habit, M. pusilla was transferred into a new monotypic genus Micromonolepis (Ulbrich 1934). The species was included in a atpB-rbcL molecular analysis, where it was unexpectedly placed within the “Chenopodieae I” clade comprising Rhagodia, Einadia and a part of Chenopodium s.l. (Kadereit et al. 2010). The papillate pericarp and the stalactite seed coat provide a good support for its placement into Chenopodieae, based on cpDNA being a part of Chenopodium s.str. (Kadereit et al. 2010, as Chenopodieae I; Figure 2). However, the limited number of taxa used in the atpB-rbcL analysis, the lack of additional molecular data and the significant morphological differences evident between Micromonolepis and the remaining Chenopodium species in this clade, such as the presence of fleshy leaves and reduced perianth segments, precludes the formal transfer of M. pusilla to Chenopodium. Further work is needed to evaluate the exact position of Micromonolepis pusilla within Chenopodieae.

Figure 7. 

Shoot of Micromonolepis pusilla showing the characteristic fleshy leaves. Photographer: Steve Matson (USA, California, Mono County, Long Valley, 2007).

Monolepis spathulata is neither Monolepis nor Blitum

Recently, Monolepis spatulata was transferred to Blitum (as B. spathulatum) based on its resemblance to other species of the genus due to the presence of a reduced number of perianth segments (Fuentes-Bazan et al. 2012b). It is evident, however, that the reduced number of perianth segments independently evolved in Chenopodieae (e.g. in Micromonolepis and some Oxybasis), Anserineae and many Dysphanieae (Sukhorukov and Zhang 2013). In light of carpological evidence (Sukhorukov 2014), it seemed doubtful that M. spathulata should be included in Blitum, as this species possesses a stalactite seed coat with a reduced protoplast. Our phylogenetic results show that Monolepis spathulata is not closely related to the other species in Monolepis (M. asiatica, and M. nuttalliana) that are now included in Blitum (Anserineae) as B. asiaticum and B. nuttallianum, respectively. This species falls within Dysphanieae forming a polytomy with Teloxys and Dysphania + Cycloloma. M. spathulata is a glabrous annual and differs from all Dysphanieae by the absence of simple hairs and subsessile glands that are diagnostic characters of this tribe. Additionally, M. spathulata is found to have the stalactite seed coat, a character missing in all Dysphanieae (Sukhorukov 2014). The close relationship between M. spathulata and the Dysphanieae, evidenced by molecular data, is unexpected given the obvious morphological and carpological differences. Indeed, M. spathulata is considered so distinct that it warrants recognition at the generic level. As the type for Monolepis, M. trifida (Trev.) Schrad. [= M. nuttalliana (Schult.) Greene], is synonymised within Blitum (as Blitum nuttallianum), a new name is required for Monolepis spathulata. As such, a new monotypic genus named Neomonolepis Sukhor., gen. nov. is established here.


Neomonolepis Sukhor., gen. nov.

Type species

Neomonolepis spathulata (A.Gray) Sukhor., comb. nov.


Annual, glabrous, branched or not; lateral branches if present ascending; leaves cauline (rosulate leaves absent), densely located, spatulate-oblong, with a short petiole up to 1 cm or sessile, entire; inflorescence leafy (bracts similar to stem leaves); flowers sessile or shortly pedicellate, unisexual intermixed in small glomerules (Figure 8); male flowers with 2-lobed hyaline perianth, stamens 1–2, anthers 0.10–0.15 mm long; female flowers without perianth, fruits 0.55–0.65 mm in diameter, almost round, with blackish papillate pericarp (when dry) that is easily raptured, styles 2(3); seeds 0.4 × 0.3 mm, reddish, with smooth surface, with small irregular pits (seen at a higher magnification), seed-coat testa with stalactites in the outer cell walls and reduced protoplast; embryo vertical.

Figure 8. 

SEM detail of the inflorescence of Neomonolepis spathulata. Abbreviations: B – bract (stained in green), FF – female flowers (orange), MF –male flower (perianth stained in blue, stamen in yellow), S – stem.

Neomonolepis spathulata (A.Gray) Sukhor., comb. nov.

Monolepis spathulata A.Gray, Proc. Amer. Acad. Arts 7: 389 (1868). Lectotype (Sukhorukov, designated here): [USA, California, Sierra Nevada], Mono Pass, 1866, H.N. Bolander 6373 lower right-hand specimen (GH00037208 [image]!, isolectotypes MO-216255 [image]! NY01085540 [image]! US00921387 [image]! YU064591 [image]!).

Blitum spathulatum (A.Gray) S.Fuentes, Uotila et Borsch, Willdenowia 42(1): 17 (2012).

Morphological notes

As Neomonolepis is a monotypic genus, the description of N. spathulata corresponds to the generic description above. Neomonolepis spathulata is morphologically distant from all Dysphanieae (Teloxys, Suckleya A.Gray, Dysphania R.Br. and Cycloloma Moq.) in being glabrous in all parts (vs. glandular and/or simple hairs), having unisexual flowers (vs. bisexual or polygamous) and ‘stalactite’ seed-coat testa (vs. ‘non-stalactite’). For this reason, we prefer to refer to the clade with the above-mentioned genera as the ‘Dysphanieae + Neomonolepis’ clade.


The type specimen lodged at GH contains several plants collected from different areas in California and almost all of them were collected after the description of Monolepis spathulata (Gray 1868). The lectotype selected here (lower right-hand specimen on the GH00037208 sheet) is a part of original material cited in the protologue as “Sierra Nevada, at Mono Pass, in loose soil, Bolander” (Gray 1868) and it is chosen in accordance with Art. 9 of ICN (Turland et al. 2018). The description of the species is consistent with the image of the lectotype. Gray (1868) also noted that the seeds of Monolepis spathulata are notably smaller than those of M. chenopodioides [= Blitum nuttallianum]. The small seed dimensions of Neomonolepis spathulata (0.4 × 0.3 mm) are similar to those observed in many Australian Dysphania (Wilson 1984 sub Chenopodium; Sukhorukov 2014).


South-western North America (USA, North Mexico).


The new generic name is composed by the prefix “neo” (new) and the core name Monolepis.


In the Chenopodioideae, some phylogenetically distant taxa often look similar due to convergence of various morphological characters, some of which were previously thought to be diagnostic such as the number of perianth segments. A remarkable example is highlighted by the different phylogenetic positions occupied by members of the former genus Monolepis, which are currently included in Anserineae (M. nuttallianaBlitum nuttallianum; M. asiaticaB. asiaticum), Dysphanieae (Neomonolepis spathulataMonolepis spathulata) and Chenopodieae (Monolepis pusillaMicromonolepis pusilla). This study shows that fruit and seed characters such as seed-coat structure are valuable traits for taxonomic study. These features are particularly useful in distinguishing the morphologically similar but phylogenetically distinct genera Blitum and Oxybasis.


We thank Eric H. Roalson and anonymous reviewers for the comments on the previous draft of the paper and Igor Pospelov and Steve Matson for the excellent images of Blitum asiaticum and Micromonolepis pusilla, respectively. The Russian Science Foundation (project 1450-00029: carpological research), Scientific programme АААА-А16-116021660045-2 of the Department of Higher Plants, Lomonosov Moscow State University (revision of the herbaria in Moscow and St.-Petersburg) and Russian Foundation for Basic Research (project 18-04-00029: revision of the herbarium collection in UK) supported the study of AS, MN and AK. The study of AE was financially supported by the Scientific programme АААА-А17-117012610055-3 of the Central Siberian Botanical Garden, SB RAS (sampling herbarium specimens from NS) and Tomsk State University competitiveness improvement programme (sampling herbarium specimens from TK).


  • Aellen P (1929) Beitrag zur Systematik der Chenopodium-Arten Amerikas, vorwiegend auf Grund der Sammlung des United States National Museum in Washington I. Feddes Repertorium 26(1–6): 31–64.
  • Aellen P (1931) Die wolladventiven Chenopodien Europas. Verhandlungen der Naturforschenden Gesellschaft in Basel 41: 77–104.
  • Aellen P, Just T (1943) Key and synopsis of the American species of the genus Chenopodium L. American Midland Naturalist 30(10): 47–76.
  • Bentham G, Hooker JD (1880) Genera Plantarum, Vol. 3, part 1. Reeve & Co., London.
  • Borsch T, Hilu KW, Quandt D, Wilde V, Neinhuis C, Barthlott W (2003) Noncoding plastid trnT-trnF sequences reveal a well resolved phylogeny of basal angiosperms. Journal of Evolutionary Biology 16(4): 558–576.
  • Bouckaert R, Heled J, Kühnert D, Vaughan T, Wu CH, Xie D, Suchard MA, Rambaut A, Drummond AJ (2014) BEAST 2: A Software platform for Bayesian evolutionary analysis. PLoS Computational Biology 10(4): e1003537.
  • Doyle JJ, Doyle JL (1987) A rapid DNA isolation procedure for small quantities of fresh leaf tissue. Phytochemical Bulletin 19: 11–15.
  • Edgar RC (2004) MUSCLE: Multiple sequence alignment with high accuracy and high throughput. Nucleic Acids Research 32(5): 1792–1797.
  • Flores-Olvera H, Vrijdaghs A, Ochoterena H, Smets E (2011) The need to re-investigate the nature of homoplastic characters: An ontogenetic case study of the ‘bracteoles’ in Atripliceae (Chenopodiaceae). Annals of Botany 108(5): 847–865.
  • Fuentes-Bazan S, Mansion G, Borsch T (2012a) Towards a species level tree of the globally diverse genus Chenopodium. Molecular Phylogenetics and Evolution 62(1): 359–374.
  • Fuentes-Bazan S, Uotila P, Borsch T (2012b) A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). Willdenowia 42(1): 5–24.
  • Giusti L (1984) Chenopodiaceae. In: Correa MN (Ed.) Flora Patagonica 4a, Tyrenc, Buenos Aires, 99–137.
  • Golenberg EM, Clegg MT, Durbin M, Doebley J, Ma DP (1993) Evolution of a noncoding region of the chloroplast genome. Molecular Phylogenetics and Evolution 2: 52–64.
  • Gray A (1868) Characters of new plants of California and elsewhere, principally of those collected by H.N. Bolander in the State Geological Survey. Proceedings of the American Academy of Arts and Sciences 7: 327–401.
  • Hall TA (1999) BioEdit: A user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series 41: 95–98.
  • Hiitonen I (1933) Suomen Kasvio. Kustannsosakeyhtiö, Helsinki.
  • Hernández-Ledesma P, Berendsohn WG, Borsch T, von Mering S, Akhani H, Arias S, Castañeda-Noa I, Eggli U, Eriksson R, Flores-Olvera H, Fuentes-Bazán S, Kadereit G, Klak C, Korotkova N, Nyffeler R, Ocampo G, Ochoterena H, Oxelman B, Rabeler RK, Sanchez A, Schlumpberger BO, Uotila P (2015) A taxonomic backbone for the global synthesis of species diversity in the angiosperm order Caryophyllales. Willdenowia 45(3): 281–383.
  • Holmgren NH (2003) Gen. Monolepis, Micromonolepis. Flora of North America, North of Mexico, Vol. 4. Oxford University Press, New York & Oxford, 300–302.
  • Hooker JD (1847) The Botany of the Antarctic Voyage Vol. II: Flora Antarctica. Reeve & Co., London.
  • Iamonico D (2011) Dysphania anthelmintica (Amaranthaceae), new to the non-native flora of Italy, and taxonomic considerations on the related species. Hacquetia 10(1): 41–48.
  • Iamonico D (2014) Taxonomical, morphological, ecological and chorological notes on Oxybasis chenopodioides and O. rubra (Chenopodiaceae) in Italy. Hacquetia 13(2): 297–302.
  • Judd WS, Ferguson IK (1999) The genera of Chenopodiaceae in the Southeastern United States. Harvard Papers in Botany 4(2): 365–416.
  • Kadereit G, Borsch T, Weising K, Freitag H (2003) Phylogeny of Amaranthaceae and Chenopodiaceae and the evolution of C4 photosynthesis. International Journal of Plant Sciences 164(6): 959–986.
  • Kadereit G, Mavrodiev EV, Zacharias EH, Sukhorukov AP (2010) Molecular phylogeny of Atripliceae (Chenopodioideae, Chenopodiaceae): Implications for systematics, biogeography, flower and fruit evolution, and the origin of C4 photosynthesis. American Journal of Botany 97(10): 1664–1687.
  • Kress WJ, Erickson DL, Jones FA, Swenson NG, Perez R, Sanjur O, Bermingham E (2009) Plant DNA barcodes and a community phylogeny of a tropical forest dynamics plot in Panama. Proceedings of the National Academy of Sciences of the United States of America 106(44): 18621–18626.
  • Krinitsina AA, Zaika MA, Speranskaya AS, Sukhorukov AP, Sizova TV (2015) A rapid and cost-effective method for DNA extraction from archival herbarium specimens. Biochemistry (Moscow) 80(11): 1478–1484.
  • Ledebour CF (1829) . Flora Altaica, Vol. 1. Reimer, Berlin.
  • Levin RA, Wagner WL, Hoch PC, Nepokroeff M, Pires JC, Zimmer EA, Sytsma KJ (2003) Family level relationships of Onagraceae based on chloroplast rbcL and ndhF data. American Journal of Botany 90(1): 107–115.
  • Linneaus C (1753) Species Plantarum, Vol. 1. Impensis Laurentii Salvii, Holmiae.
  • Löhne C, Borsch T (2005) Molecular evolution and phylogenetic utility of the petD group II intron: A case study in basal angiosperms. Molecular Biology and Evolution 22(2): 317–332.
  • Moore DM (1983) Flora of Tierra del Fuego. Missouri Botanical Garden, St. Louis.
  • Moquin-Tandon A (1849) Salsolaceae [Chenopodiaceae]. In de Candolle A (Ed.) Prodromus systematis naturalis regni vegetabilis, Vol. 13(2). Typ. Masson, Paris, 43–219.
  • Mosyakin SL (1996) Chenopodium [s.l.]. In: Tzvelev NN (Ed.) Flora of Eastern Europe, Vol.9. Mir & Semya-95, St.-Petersburg, 27–44.
  • Mosyakin SL (2013) New nomenclatural combinations in Blitum, Oxybasis, Chenopodiastrum, and Lipandra (Chenopodiaceae). Phytoneuron 2013–56: 1–8.
  • Mosyakin SL, Iamonico D (2017) Nomenclatural changes in Chenopodium (incl. Rhagodia) (Chenopodiaceae), with considerations on relationships of some Australian taxa and their possible Eurasian relatives. Nuytsia 28: 255–271.
  • Müller J, Müller K, Neinhuis C, Quandt D (2010) PhyDE: Phylogenetic Data Editor v 0.9971.
  • Reiche KF (1911) Estudios críticos de la Flora de Chile. Anales de la Universidad de Chile 6: 148–159.
  • Scott AJ (1978) A review of the classification of Chenopodium L. and related genera (Chenopodiaceae). Botanische Jahrbücher für Systematik. Pflanzengeschichte und Pflanzegeographie 100: 205–220.
  • Simón LE (1997) Variations des caractères foliaires chez Chenopodium subgen. Ambrosia sect. Adenois (Chenopodiaceae) en Amèrique du Sud: Valeur taxonomique et èvolutive. Adansonia, ser. 3 19(2): 293–320.
  • Sukhorukov AP (1999) Eine neue asiatische Chenopodium-Art aus der Sektion Pseudoblitum Hook. fil. (Chenopodiaceae). Feddes Repertorium 110(7–8): 493–497.
  • Sukhorukov AP (2006) Zur Systematik und Chorologie der in Russland und benachbarten Staaten (in den Grenzen der ehemaligen UdSSR) vorkommenden Atriplex-Arten (Chenopodiaceae). Annalen des Naturhistorischen Museums in Wien 108B: 307–420.
  • Sukhorukov AP (2014) The carpology of the Chenopodiaceae with reference to the phylogeny, systematics and diagnostics of its representatives. Grif & Co., Tula. [in Russian with English summary]
  • Sukhorukov AP, Zhang M (2013) Fruit and seed anatomy of Chenopodium and related genera (Chenopodioideae, Chenopodiaceae/Amaranthaceae): Implications for evolution and taxonomy. PLoS One 8(4): e61906.
  • Sukhorukov AP, Uotila P, Zhang M, Zhang HX, Speranskaya AS, Krinitsyna AA (2013) New combinations in Asiatic Oxybasis (Amaranthaceae s.l.): Evidence from morphological, carpological and molecular data. Phytotaxa 144(1): 1–12.
  • Sukhorukov AP, Mavrodiev EV, Struwig M, Nilova MV, Dzhalilova KK, Balandin SA, Erst A, Krinitsyna AA (2015a) One-seeded fruits in the core Caryophyllales: Their origin and structural diversity. PLoS One 10(2): e0117974.
  • Sukhorukov AP, Zhang M, Kushunina M (2015b) A new species of Dysphania (Chenopodioideae, Chenopodiaceae) from South-West Tibet and East Himalaya. Phytotaxa 203(2): 138–146.
  • Swofford DL (2002) PAUP* Phylogenetic Analysis Using Parsimony (*and other methods). Version 4. Sinauer Associates, Sunderland.
  • Taberlet P, Gielly L, Pautou G, Bouvet J (1991) Universal primers for amplification of three non-coding regions of chloroplast DNA. Plant Molecular Biology 17(5): 1105–1109.
  • Theodorova TA (2014) Gen. Chenopodium, Blitum (incl. Oxybasis, Lipandra, Chenopodiastrum). In: Mayevsky PF (Ed.) Flora of the central part of European Russia, Ed.11. KMK Press, Moscow, 91–93.
  • Turland NJ, Wiersema JH, Barrie FR, Greuter W, Hawksworth DL, Herendeen PS, Knapp S, Kusber WH, Li DZ, Marhold K, May TW, McNeill J, Monro AM, Prado J, Price MJ, Smith GF (Eds) (2018) International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code): Adopted by the Nineteenth International Botanical Congress Shenzhen, China, July 2017. Regnum Vegetabile 159. Koeltz Botanical Books, Glashütten.
  • Ulbrich E (1934) Chenopodiaceae. In: Engler A, Harms A (Eds) Die Natürlichen Pflanzenfamilien (2nd edn), Vol.16c. Engelmann, Leipzig, 379–584.
  • Uotila P (1993) Taxonomic and nomenclatural notes on Chenopodium in the Flora Iranica area. Annales Botanici Fennici 30: 189–194.
  • Uotila P (1997) Chenopodium (s.l.). In: Rechinger KH (Ed.) Flora des Iranischen Hochlandes und der umrahmenden Gebirge, Vol.172. Akademische Druck- und Verlagsanstalt, Graz, 24–59.
  • Uotila P (2017) Notes on the morphology and taxonomy of Chenopodiastrum (Chenopodiaceae/Amaranthaceae s. lato), with two new combinations, C. erosum from Australia and C. gracilispicum from China. Annales Botanici Fennici 54(4–6): 345–352.
  • Watson S (1871) United States Geological Explorations of the fortieth parallel. Botany, Vol. 5. Government Printing Office, Washington.
  • White TJ, Bruns T, Lee S, Taylor J (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (Eds) PCR Protocols: a guide to methods and applications.Academic Press, New York, 315–322.
  • Wilson PG (1984) Chenopodiaceae. In: George AS (Ed.) Flora of Australia, Vol.4. Australian Government Publishing Service, Canberra, 81–317.
  • Zacharias EH, Baldwin BG (2010) A molecular phylogeny of North American Atripliceae (Chenopodiaceae), with implications for floral and photosynthetic pathway evolution. Systematic Botany 35(4): 839–857.
  • Zhu GL, Sanderson SC (2017) Genera and a new evolutionary system of World Chenopodiaceae. Science Press, Beijing.
  • Zuloaga FO, Morrone O (1999) Catálogo de las plantas de la República Argentina II (Acanthaceae-Euphorbiaceae). Missouri Botanical Garden, St. Louis.