Delimitation Of Taxa Research Articles

Molecular diversity and species delimitation in the genus Mideopsis Neuman, 1880 in Europe (Acari, Hydrachnidia, Mideopsidae)

Water mites of the genus Mideopsis are often a very abundant member of running and standing water communities whose taxonomy has been based almost exclusively on traditional morphological studies. In this study, we present a species-level phylogeny of the genus in Europe using 71 cytochrome c oxidase subunit I (COI) barcodes available in the BOLD database. In addition to morphological identification, we applied two different molecular taxon delimitation approaches (Assemble Species by Automatic Partitioning - ASAP and multi-rate Poisson tree processes). The ASAP molecular delimitation revealed the presence of five molecular operational taxonomic units (MOTU), i.e., M. crassipes Soar, 1904, M. milankovici Pešić & Smit, 2020, M. roztoczensis Biesiadka & Kowalik, 1979 and two distinct M. orbicularis MOTUs, both widely distributed and sympatric in Central and Northern Europe. Morphological analysis revealed that specimens of Clade 1 match the description given by Biesiadka & Kowalik (1979) for Mideopsis orbicularis. We highlight the need for a thorough revision of the genus Mideopsis in Europe by integrating morphological and molecular data.

The peculiar case of Myxicola infundibulum (Polychaeta: Sabellidae): echo from a science 200 years old and description of four new taxa in the Mediterranean Sea

Myxicola infundibulum Montagu, 1808 is the most reported species of its genus, showing an unusually wide distribution from the Mediterranean area to Australia, North Europe, and North America, a situation deriving from a wide synonymizing of numerous species with M. infundibulum. Recently, genetic analysis confirmed that the Australian form of this species is an introduced taxon from the Mediterranean area, while the examined North American specimens were genetically and morphologically different. In the present paper we travel through the history of M. infundibulum from the first descriptions, trying to trace both the origin of this taxon and the origin of its wide distribution, through an analysis of the descriptions of all valid and invalid taxa to date. We also examined material present in the collection of one of the authors previously identified as M. infundibulum, comparing Mediterranean material to some from the English Channel, and material from North America. This led to the erection of four taxa new to science from material recently collected along the Italian coasts, and the restoration of Myxicola pacifica Johnson, 1901. Delimitation of taxa is based only on morphology, and we propose new morphological features to be considered; however, a molecular examination is planned in the near future. http://zoobank.org/urn:lsid:zoobank.org:pub:7CF64CB2-8B9C-4001-BE57-199B5F95213B

Trichomes in the megadiverse genus Croton (Euphorbiaceae): a revised classification, identification parameters and standardized terminology

Abstract Trichomes are key functional traits that protect plants against abiotic stresses, herbivores and pathogens. In addition to their ecological roles, trichomes show high morphological variability in many lineages, providing useful characters for species characterization and taxon delimitation. Here, we focus on trichomes in Croton, a megadiverse genus (c. 1200 spp.) of Euphorbiaceae, in which these structures are ubiquitous and exhibit significant variation in form, location on the plant body, density and function. Owing to their functional and taxonomic relevance and the current need for further standardization of their terminology and classification, we revised previous trichome classifications used in the genus. We also provide new trichome data by expanding taxon sampling and using different methodological approaches in plant anatomy to improve understanding of the structural patterns of the trichome types present in the genus. On the basis of our results and literature review, we propose a new classification for trichomes in Croton based on well-defined parameters; this clarifies existing redundancies, is consistent with anatomical evidence and can be easily updated as new types are revealed in future surveys. This contribution will improve communication among taxonomists and promote more meaningful morphological comparability across systematics studies, including those focusing on morphological evolution and functional traits.

Diversity of Water Frogs Pelophylax spp. in Turkey: Do Mating Vocalizations Mirror Nominal Taxon Delimitation?

Informed conservation management requires exact knowledge on the species diversity of the taxon group in focus within a geographic area, specifically on the occurrence of endemics. In Turkey, there are three water frog taxa of the genus Pelophylax; one is the widespread P. bedriagae, the other two are geographically restricted to either Thrace (P. ridibundus) or to the Anatolian Lake district (P. caralitanus). The species status of the Beyşehir frog P. caralitanus has been questioned since its proposal in 2001. We recorded and analyzed advertisement and release vocalizations at representative populations of Pelophylax taxa to assess the degree of inter-taxon differentiation and the potential for premating isolation. We found that P. bedriagae and P. caralitanus have much more similar vocalizations than both have compared to P. ridibundus. A functional bioacoustic premating barrier between bedriagae and caralitanus in syntopy does not exist according to our study. The low degree of bioacoustic differentiation mirrors earlier genetic, karyological, and morphological findings. We conclude that the Beyşehir frogs do not deserve species status and that P. caralitanus should be considered a junior synonym of P. bedriagae. Therefore, the number of endemic anuran species in Turkey decreases to one.

Petiole micromorphology in Brassicaceous taxa and its potential for accurate taxonomic identification

Petiole anatomy is considered one of the important diagnostic characteristics that can be effectively employed in taxa discrimination at the species level. In this study, comprehensive petiole anatomy of 25 wild Brassicaceae taxa from Northern Baluchistan was carried out to examine variations in petiole anatomical features that are significant in the identification and delimitation of species. The current research first time reported Goldbachia pendula from Pakistan. The study also includes endemic taxa Farsetia hamiltonii. Variations observed among qualitative (shapes of petiole, epidermis, collenchyma, chlorenchyma, sclerenchyma, trichome, cuticle, xylem vessel, phloem, collenchyma, chlorenchyma, sclerenchyma, arrangement and several vascular bundles, presence/absence of pith, the sub-epidermal ring of collenchyma) and quantitative (diameter of petiole, pith, vascular bundles) characteristics of the petiole. Observed shapes of petiole were sulcate, flat, oval or circular with blunt or acute wings. Vascular bundles in petioles were collateral closed, collateral open, bi-collateral, or hadrocentric types with arrangements of single, 1 + 2 (one large central, two lateral) and numerous (2–20). The surfaces of petioles were marked with three types of trichomes unicellular, uniseriate, and multiseriate. Petiole of Physorrhynchus brahuicus was the largest (length 2561.8 µm, width 2004 µm). The highest numbers of vascular bundles (20) were observed in the Alyssum desertorum. Conringia orientalis possessed the largest pith (length 1711.6 µm 850.4 µm). The parameters were collected into a matrix and statistically analyzed the ability of variables to segregate taxa using Past 4.03. PCA clustering, UPGMA dendrogram revealed comparability and negative correlation at genus, among species of the same genus and distinct species. Via documentation of distinct microscopic petiolar anatomical variables, the study will be significant for the characterization and delimitation of taxa at genus and species level in the family Brassicaceae, the exploration of evolutionary and microclimatic effects on designing anatomy of taxa in distinct floristic regions.

Genomic, spatial and morphometric data for discrimination of four species in the Mediterranean Tamus clade of yams (Dioscorea, Dioscoreaceae).

Among the numerous pantropical species of the yam genus, Dioscorea, only a small group occurs in the Mediterranean basin, including two narrow Pyrenean endemics (Borderea clade) and two Mediterranean-wide species (D. communis and D. orientalis, Tamus clade). However, several currently unrecognized species and infraspecific taxa have been described in the Tamus clade due to significant morphological variation associated with D. communis. Our overarching aim was to investigate taxon delimitation in the Tamus clade using an integrative approach combining phylogenomic, spatial and morphological data. We analysed 76 herbarium samples using Hyb-Seq genomic capture to sequence 260 low-copy nuclear genes and plastomes, together with morphometric and environmental modelling approaches. Phylogenomic reconstructions confirmed that the two previously accepted species of the Tamus clade, D. communis and D. orientalis, are monophyletic and form sister clades. Three subclades showing distinctive geographic patterns were identified within D. communis. These subclades were also identifiable from morphometric and climatic data, and introgression patterns were inferred between subclades in the eastern part of the distribution of D. communis. We propose a taxonomy that maintains D. orientalis, endemic to the eastern Mediterranean region, and splits D. communis sensu lato into three species: D. edulis, endemic to Macaronesia (Canary Islands and Madeira); D. cretica, endemic to the eastern Mediterranean region; and D. communis sensu stricto, widespread across western and central Europe. Introgression inferred between D. communis s.s. and D. cretica is likely to be explained by their relatively recent speciation at the end of the Miocene, disjunct isolation in eastern and western Mediterranean glacial refugia and a subsequent westward recolonization of D. communis s.s. Our study shows that the use of integrated genomic, spatial and morphological approaches allows a more robust definition of species boundaries and the identification of species that previous systematic studies failed to uncover.

Taxonomic revision of the cultivated species of Mimusops (Sapotaceae) in Egypt, with new records

During the process of updating horticultural records of this genus in Egypt, five problems were identified: lack of publications, lack of clarity between species, numerous errors of identifications, loss of earlier documented records of identity, as well as, the introduction and cultivation of new plants during the 19th Century added to the complexity of the problem. In this study, the taxonomic aspects of genus Mimusops, were thoroughly studied to identify the most reliable characters for taxon delimitation. Our assessment was based on morphological characters representing habit, leaves, petioles, flowering pedicels, buds, floral parts, fruit and seed. Fieldwork have revealed the presence of four species, of which Mimusops kummel and M. zeyheri are new records. The latter species is represented in Egypt by M. zeyheri var. laurifolia. This variety has been neglected by many authors. Additionally, Mimusops elengi L. was believed to be cultivated in Egypt, but no materials have been encountered that could confirm it. The specimens earlier identified as M. elengi actually belong either to M. kummel or to M. laurifolia. A detailed description of the genus and species with photographs, an identification key, and synonymy for each taxon are provided.

DNA barcoding unveils a high diversity of caddisflies (Trichoptera) in the Mount Halimun Salak National Park (West Java; Indonesia).

Trichoptera are one of the most diverse groups of freshwater insects worldwide and one of the main bioindicators for freshwater quality. However, in many areas, caddisflies remain understudied due to lack of taxonomic expertise. Meanwhile, globally increasing anthropogenic stress on freshwater streams also threatens Trichoptera diversity. To assess the Trichoptera diversity of the area within and around the Mount Halimun Salak National Park (MHSNP or Taman Nasional Gunung Halimun Salak) in West Java (Indonesia), we conducted a molecular-morphological study on Trichoptera diversity using larvae from a benthic survey and adults from hand-netting. In addition to morphological identification, we applied four different molecular taxon delimitation approaches (Generalized Mixed Yule Coalescent, Bayesian Poisson Tree Processes, Automatic Barcode Gap Discovery and Assemble Species by Automatic Partitioning) based on DNA barcoding of Cytochrome-C-Oxidase I (COI). The molecular delimitation detected 72 to 81 Operational Taxonomic Units (OTU). Only five OTUs could be identified to species level by comparing sequences against the BOLD database using BLAST, and four more to the genus level. Adults and larvae could be successfully associated in 18 cases across six families. The high diversity of Trichoptera in this area highlights their potential as bioindicators for water quality assessment. This study provides an example of how molecular approaches can benefit the exploration of hidden diversity in unexplored areas and can be a valuable tool to link life stages. However, our study also highlights the need to improve DNA barcode reference libraries of Trichoptera for the Oriental region.

A long-flowering Hechtia (Bromeliaceae): Hechtia sanchezii, a new species from San Luis Potosí, Mexico

Background: Hechtia is known among Bromeliaceae by its unisexual, sexually dimorphic, mainly fragrant flowers and dioecy; delimitation of taxa particularly on those with lateral inflorescence, requires qualitative morphological evidence from both sexes, because dimensions of structures change during its growth.
 Hypotheses: Hechtia species are delimitated based on a combination of discrete morphological characters from both sexes, associated with narrow geographical distributions. If examination of populations of San Luis Potosí shows characters that place the taxon in the genus and distinguish it from other species in Hechtia, the taxon will be described as new.
 Taxon: Hechtioideae, Hechtia sp. nov.
 Study site and dates: Mexican State of San Luis Potosí and vicinities, 2015-2021.
 Methods: Live plants as well as herbarium material of the new taxon and the most morphological similar species, were analyzed, with examination of inflorescences and flowers of both sexes, fruits, and seeds. Geographical distribution was mapped and conservation status using IUCN criteria is reported for the new species.
 Results: Hechtia sanchezii has been confused with H. glomerata since both share lateral, glomerulate-like infructescences, but H. sanchezii shows red to ferruginous indumenta on floral bracts and sepals (vs. white), these red (vs. greenish or brownish), pink petals (vs. white), scentless (vs. fragrant) flowers, stamens with filaments of two lengths, three epipetalous, and three alternating with petals (vs. two lengths but all filaments epipetalous).
 Conclusions: Morphological and geographical evidence allow the recognition of H. sanchezii as a new species native from San Luis Potosí, Mexico.

Comparative Morpho-Anatomical Investigation of Leaves of Triumfetta tomentosa Boj. and Triumfetta rhomboidea Jacq.

The plant species Triumfetta tomentosa Boj. and Triumfetta rhomboidea Jacq using Standard procedures were investigated on morphological characters. The morphological assessment of the species revealed great similarities in their habit, indumentum, nature and type of stem and leaf apices. The differences were seen in their habitat and the number of flowers in the racemose inflorescence. In the foliar anatomy of the species, anisocytic stomata type, the presence of stellate trichomes on both surfaces and the presence of calcium crystals were common in both species. The differences existed in the amphistomatic distribution in T. rhomboidea and hypostomatic distribution in T. tomentosa. The number, length and width of the stomata, stomata pore and guard cells, the number, length and width of the epidermal cells of and the length of trichomes varied greatly in both species. A combination of morphological and anatomical data alongside others bring about authentication in the delimitation of taxa.

Palynological diversity of highly medicinal rare, endangered, and threatened plants from Western Himalaya, India

The present study investigated the palynological diversity of highly medicinal Rare, Endangered, and Threatened (RET) plant species dwelling in higher altitudes of Western Himalaya, India. The pollen morphology of 32 plant species covering 29 genera, 23 families, and 18 orders of Angiosperms was analyzed by Light Microscopy (LM) and Scanning Electron Microscopy (SEM). The families of the studied plant species have been arranged and discussed following the evolutionary sequence as per the updated version of Angiosperm Phylogeny Group ІV. The studied pollen characters were found to be helpful in the delimitation of taxa at the species level. In the studied monocots, the species belonging to order Zingiberales, Asparagales, and Liliales followed the general trend of having primitive inaperturate to advance monosulcate pollen except for Alismatales which had inaperturate pollen and placed after the orders mentioned above in the APG ІV classification system. The pollen aperture of the eudicot group in the present study followed the evolutionary pattern from tricolpate to tricolporate and triporate, which corroborated previous reports. All the investigated species of both monocot and eudicot groups had monad pollen units suggesting their primitiveness on the evolutionary scale except for the Rhododendron companulatum (Ericales), having evolutionarily advanced tetrad arrangement. The current study found primitive exine ornamentation in Ranunculales to advance in Asterales, Lamiales, Gentianales, and Boraginales and confirms the results of the previous studies. The data on the pollen morphological features of the studied species generated in the present study will help understand these important high-altitude plant species' reproductive biology and conservation aspects.

Phylogenomic analysis of 997 nuclear genes reveals the need for extensive generic re-delimitation in Caesalpinioideae (Leguminosae).

Subfamily Caesalpinioideae with ca. 4,600 species in 152 genera is the second-largest subfamily of legumes (Leguminosae) and forms an ecologically and economically important group of trees, shrubs and lianas with a pantropical distribution. Despite major advances in the last few decades towards aligning genera with clades across Caesalpinioideae, generic delimitation remains in a state of considerable flux, especially across the mimosoid clade. We test the monophyly of genera across Caesalpinioideae via phylogenomic analysis of 997 nuclear genes sequenced via targeted enrichment (Hybseq) for 420 species and 147 of the 152 genera currently recognised in the subfamily. We show that 22 genera are non-monophyletic or nested in other genera and that non-monophyly is concentrated in the mimosoid clade where ca. 25% of the 90 genera are found to be non-monophyletic. We suggest two main reasons for this pervasive generic non-monophyly: (i) extensive morphological homoplasy that we document here for a handful of important traits and, particularly, the repeated evolution of distinctive fruit types that were historically emphasised in delimiting genera and (ii) this is an artefact of the lack of pantropical taxonomic syntheses and sampling in previous phylogenies and the consequent failure to identify clades that span the Old World and New World or conversely amphi-Atlantic genera that are non-monophyletic, both of which are critical for delimiting genera across this large pantropical clade. Finally, we discuss taxon delimitation in the phylogenomic era and especially how assessing patterns of gene tree conflict can provide additional insights into generic delimitation. This new phylogenomic framework provides the foundations for a series of papers reclassifying genera that are presented here in Advances in Legume Systematics (ALS) 14 Part 1, for establishing a new higher-level phylogenetic tribal and clade-based classification of Caesalpinioideae that is the focus of ALS14 Part 2 and for downstream analyses of evolutionary diversification and biogeography of this important group of legumes which are presented elsewhere.

Comparative leaf blade anatomical analysis of the annual Polygonum s. str. taxa from the Balkan Peninsula and the Pannonian Plain

Leaf blade anatomy in six annual plant taxa of the genus Polygonum from the western and central regions of the Balkan Peninsula and the southern region of the Pannonian Plain was analyzed. The aim was to compare the anatomical characteristics of the leaf blades and identify the diagnostic significance of these traits in the taxonomy of the studied taxa. The analyses included 32 populations, and focused on 18 quantitative (14 basic and 4 derived) and 5 qualitative traits. A detailed description of the leaf anatomy was also provided for all examined taxa. Based on the statistical analysis and tests conducted on the quantitative leaf blade anatomical traits, it is possible to distinguish P. albanicum from the remaining taxa (P. arenarium subsp. arenarium, P. arenarium subsp. pulchellum, P. arenastrum, P. aviculare, and P. graminifolium). However, the analyzed quantitative characteristics did not contribute to the delimitation of the remaining taxa or to the formation of new groups within this genus. Consequently, they are insufficient for the separation of the examined taxa, but can provide important additional taxonomic information. On the other hand, the results yielded by nonparametric statistical analyses confirm that the analyzed qualitative traits, the midrib protrusion in particular, and the presence and level of protrusion of the lateral ribs, are valuable in taxa delimitation.

Leaf anatomical characters variation of Strobilanthes s.l. from Sumatra, Indonesia and its taxonomic implications

Abstract. Suratman, Suranto, Muzzazinah, Purnomo. 2022. Leaf anatomical characters variation of Strobilanthes s.l. from Sumatra, Indonesia and its taxonomic implications. Biodiversitas 23: 3705-3720. The objective of this study was to evaluate leaf anatomical character variation among species of Strobilanthes s.l. from Sumatra. A total of 35 species from four genera previously recognized within the subtribe Strobilanthineae (Strobilanthes, Hemigraphis, Sericocalyx, Semnostachya) were used for leaf paradermal section observations. A total of seventeen leaf anatomical characters consisting of ten quantitative and seven qualitative characters were selected for leaf anatomical comparison. The quantitative and qualitative character analysis showed great variability in the majority of tested leaf anatomical characters. This result indicates the large diversity of leaf anatomical characters occurs among species of Strobilanthes s.l. A similarity dendrogram among species of Strobilanthes s.l. based leaf anatomical character data revealed two major clusters. The first cluster consists of eleven species with regular epidermal cell shape and straight cell wall with a similarity coefficient of 0.67. The second cluster consists of twenty four species that differed from species in the first cluster due to their irregular epidermal cell shape and undulate anticlinal cell wall with a similarity coefficient of 0.59. This study indicates that leaf anatomical characters are valuable taxonomic features in taxa delimitation at the species level. The results of this study also support earlier works through molecular studies that all members of the Strobilanthinae then accepted as Strobilanthes s.l. group which could not be easily split into smaller component genera.

Genome Size Variation in Dianthus sylvestris Wulfen sensu lato (Caryophyllaceae).

Genome size (GS) is an important characteristic that may be helpful in delimitation of taxa, and multiple studies have shown correlations between intraspecific GS variation and morphological or environmental factors, as well as its geographical segregation. We estimated a relative GS (RGS) of 707 individuals from 162 populations of Dianthus sylvestris with a geographic focus on the Balkan Peninsula, but also including several populations from the European Alps. Dianthus sylvestris is morphologically variable species thriving in various habitats and six subspecies have been recognized from the Balkan Peninsula. Our RGS data backed-up with chromosome counts revealed that the majority of populations were diploid (2n = 30), but ten tetraploid populations have been recorded in D. sylvestris subsp. sylvestris from Istria (Croatia, Italy). Their monoploid RGS is significantly lower than that of the diploids, indicating genome downsizing. In addition, the tetraploids significantly differ from their diploid counterparts in an array of morphological and environmental characteristics. Within the diploid populations, the RGS is geographically and only partly taxonomically correlated, with the highest RGS inferred in the southern Balkan Peninsula and the Alps. We demonstrate greater RGS variation among the Balkan populations compared to the Alps, which is likely a result of more pronounced evolutionary differentiation within the Balkan Peninsula. In addition, a deep RGS divergence within the Alps likely points to persistence of the alpine populations in different Pleistocene refugia.

Macro-Morphological and Ecological Variation in Rosa sericea Complex

Taxon delimitation and identification are important in many areas of biology, especially in taxonomy and conservation. Taxonomic treatment is required to establish and justify recommendations in conservation biology for the group being considered. Imperfect and controversial taxonomy can undermine conservation assessment. We studied 71 populations; 665 individuals corresponding to the morphology of the Rosa sericea complex (including six taxa, one of which has extremely narrow distributions) were collected from sympatric, parapatric, and allopatric populations distributed in China. This study aims to investigate whether the complex species are macromorphologically different species and evaluate the rare taxa of the complex for conservation priority. The morphological characters and principal component analysis (PCA) of the R. sericea complex showed that the complex species have overlapping characters but can distinguish morphologically. The species of R. sericea complex systematics status based on previous DNA sequencing is controversial. The ecological habitat’s current morphological characters only delimit the R. morrisonensis (in Taiwan). To evade mistakes in species conservation, we recommend that taxonomical knowledge be needed to ensure success in protecting target species. Thus, the complementarity of systemic and conservation assurance makes conservation actions more necessary for the complex’s rare taxa. The ecological niche modelling (ENM) results showed that habitats of these conspecific taxa would be shrunken. With the presence of snapshots in time, the geography of taxa might decrease rapidly in representative entirely of the Geographic space (G-space) and Environmental space (E-space) that such taxa are bright to inhabit. So far, the significant inferences meant for the niche occupy the most incredible comparative research, taking the impermanent nature of taxa distributions and undertaking that such species are at a state of stability. If the artificially identified species (rarely distributed) are based on morphological identification, they must be conserved.

Taxonomic and nomenclatural update of Cenostigma (Leguminosae: Caesalpinioideae) in Cuba

Caesalpinia s.l. is a traditionally polymorphous and unnatural genus, which was finally segregated into 27 genera based on robust phylogenetic analysis. Three of the Caesalpinia species recognized in the Flora of the Republic of Cuba were transferred to Cenostigma, while the infraspecific taxa of the two endemic species were not accepted. In this sense, the delimitation of taxa and nomenclature of Cenostigma in Cuba is reviewed. Only Cenostigma myabense var. clementis is recognized as an infraspecific taxon in Cenostigma myabense and the new combination is presented. The infraspecific classification of Caesalpinia pinnata is accepted and three new combinations are presented: Cenostigma pinnatum subsp. oblongifolium, Cenostigma pinnatum var. oblongifolium and Cenostigma pinnatum var. savannarum. The lectotypes for five names are designated: Caesalpinia myabensis, Libidibia pauciflora var. puberula, Caesalpinia hermeliae, Caesalpinia hornei, and Caesalpinia savannarum. The second step lectotype of Poincianella clementis is designated. The diagnosis of all taxa is presented, and nomenclatural information and geographic distribution are included here. In this way, worldwide the Cenostigma genus is composed of 14 species (three in Cuba, two endemic), one subspecies (endemic to Cuba) and nine varieties (two endemic to Cuba).

Significance of seed morphology and anatomy in the systematics of Musaceae

AbstractThe paper deals with the seed morphology and anatomy of 32 wild Indian Musaceae by using light microscopy (LM) and scanning electron microscopy (SEM). This is the first comprehensive investigation into the seed micro-morphological and anatomical aspects of two genera of the family. Seed characters including shape, size, surface sculpturing (LM and SEM), seed coat thickness, layer characters and chalazal chamber column were considered. Seed characters play a significant role in the delimitation of taxa as they are more stable than vegetative (anatomical) and pollen features. Four types of seeds (oblate, ovoid, sub-globose and ellipsoid) were observed in the family, oblate seeds being the most common. LM revealed that most of the seeds have verrucate surface sculpturing, but some are smooth-verrucate or smooth. Seed size also plays an important role in the identification of the taxa to some extent. Number of layers and seed coat thickness are directly proportional to seed size. However, the thickness of endotesta, tegmen and inner endosperm layers (aleurone layers) differ in small and large seeds. The present study revealed eight types of outer sculpturing and three inner sculpturing patterns with diverse nature of anticlinal and periclinal cell walls. Based on the seed characters, a phenetic analysis was also carried out.

Molecular, micromorphological and anatomical study of rangeland species of Atriplex (Chenopodiaceae) in Iran

Atriplex, as the largest genus of the Chenopodiaceae, is well known for its taxonomic complexity resulting from overlapping morphological characters. This halophytic perennial is distributed in salty and dry soils of Eurasia, America and Australia. Atriplex is one of the most widely cultivated rangeland species in Iran, which improves and revitalizes the rangelands. These unique characteristics of Atriplex make it a valuable plant. The present study is the first micromorphological investigation of this genus in Iran. In this study, the molecular evidence, micromorphological and anatomical structure of four species of Atriplex have been considered to evaluate their relationships. The basic shape of the pollen grains in most taxa is subprolate, however prolate and spheroidal pollen grains were recorded for A. lentiformis and A. canescens. One type of trichome (glandular) is described. Here, among the glandular trichomes, density and size of trichomes are considered as valuable characteristics. Micromorphology of epidermis illustrated three types of epidermal cells including puzzle-shaped, polygonal and irregular. Stem cross sections showed rounded shape, but the margins are diff erent between four species. Using nuclear and plastid markers (nrDNA ITS and rpl32-trnL(UAG)), we reconstructed phylogenetic relationships within four species of Atriplex. This data set was analyzed by phylogenetic methods including Bayesian inference, maximum likelihood and maximum parsimony. In phylogenetic analyses, all members of four species formed a well-supported clade (PP = 1; ML/BS = 100/100), divided into three major subclades (I, II and III). The results of the present study showed the usefulness of micromorphological, anatomical and molecular characteristics in taxon delimitation at specific levels.

Molecular, micromorphological and anatomical study of rangeland species of Atriplex (Chenopodiaceae) in Iran

Atriplex, as the largest genus of the Chenopodiaceae, is well known for its taxonomic complexity resulting from overlapping morphological characters. This halophytic perennial is distributed in salty and dry soils of Eurasia, America and Australia. Atriplex is one of the most widely cultivated rangeland species in Iran, which improves and revitalizes the rangelands. These unique characteristics of Atriplex make it a valuable plant. The present study is the first micromorphological investigation of this genus in Iran. In this study, the molecular evidence, micromorphological and anatomical structure of four species of Atriplex have been considered to evaluate their relationships. The basic shape of the pollen grains in most taxa is subprolate, however prolate and spheroidal pollen grains were recorded for A. lentiformis and A. canescens. One type of trichome (glandular) is described. Here, among the glandular trichomes, density and size of trichomes are considered as valuable characteristics. Micromorphology of epidermis illustrated three types of epidermal cells including puzzle-shaped, polygonal and irregular. Stem cross sections showed rounded shape, but the margins are diff erent between four species. Using nuclear and plastid markers (nrDNA ITS and rpl32-trnL(UAG)), we reconstructed phylogenetic relationships within four species of Atriplex. This data set was analyzed by phylogenetic methods including Bayesian inference, maximum likelihood and maximum parsimony. In phylogenetic analyses, all members of four species formed a well-supported clade (PP = 1; ML/BS = 100/100), divided into three major subclades (I, II and III). The results of the present study showed the usefulness of micromorphological, anatomical and molecular characteristics in taxon delimitation at specific levels.