Ihsan A. Al-Shehbaz

Instituto de Botánica Darwinion, Darwin, Río Negro, Argentina

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Publications (92)132.53 Total impact

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    ABSTRACT: Tribe Eudemeae comprises a group of genera distributed along the Andes.•Phylogenetic analyses included species of all genera and four loci.•Eudemeae s.str. (excluding Delpinophytum) represents a monophyletic group.•Two main lineages differentiated in their geographical distribution are present.•Multiple gains or losses of the diagnostic morphological characters were recovered.
    Molecular Phylogenetics and Evolution 01/2015; 82. · 4.07 Impact Factor
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    ABSTRACT: A general review of the taxonomic status of Thlaspi past and present is given, and a critical evaluations of its segregates based on both morphological and molecular data are presented. ITS molecular phylogenetic study of Thlaspi aghricum and related species, as well as seed-coat morphology and anatomy strongly support the placement of the species in Noccaea. The new combination N. aghrica is proposed, and detailed description and distribution of the species are given.
    Phytotaxa 09/2014; 178(4):287-297. · 1.38 Impact Factor
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    ABSTRACT: The Malcolmia s.l. complex was so broadly delimited that it included at least five genera in four tribes. As delimited herein, it includes Malcolmia s.str. (12 taxa, 6 spp.) of the tribe Malcolmieae, Maresia (5 spp.) and the new genus Marcus-Kochia (4 spp.) of the tribe Anastaticeae, Strigosella (23 spp.) of the tribe Euclidieae, and Zuvanda (3 spp.) of the tribe Conringieae. The new combinations M.-K. arenaria, M.-K. littorea, M.-K. ramosissima, and M.-K. triloba are proposed. Detailed generic descriptions, key to genera and their species, and data on type collections of all recognized taxa are provided. Second-step lectotypes are designated keys for Strigosella hispida, S. scorpioides, and Zuvanda meyeri. All taxa previously placed in Malcolmia are listed, and their current tribal, generic, and species assignments are given.
    Harvard Papers in Botany 07/2014; 19(1):53-71.
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    Diego L. Salariato, Ihsan A. Al-Shehbaz
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    ABSTRACT: Abstract— Zuloagocardamum jujuyensis , a new genus and species of Brassicaceae from Jujuy Province in Argentina, is described and illustrated, and its phylogenetic relationships to nearest relatives are demonstrated. It resembles some genera of the tribe Thelypodieae, such as Chilocardamum and Weberbauera, but differs mainly by having a well-developed woody caudex with reduced leafless stems, rosulate, awl-shaped or linear, sessile, parallel-veined basal leaves conspicuously ciliate with simple trichomes, racemes much shorter than the basal leaves, torulose fruits, and mucilaginous seeds. Phylogenetic analyses, based on DNA sequences of nuclear ITS and plastid ndhF and trnL-F regions, place Z. jujuyensis in the tribe Thelypodieae, where it is related to species of Weberbauera, Englerocharis, and Parodiodoxa. However, it is morphologically different from species of all four genera by the character combinations above.
    Systematic Botany 01/2014; 39(2). · 1.29 Impact Factor
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    ABSTRACT: Erysimum includes 150–350 species distributed in the Northern Hemisphere, with Eurasia being the centre of greatest diversity. It is well known for its taxonomic complexity as a result of overlapping morphological characters. We present the first densely sampled phylogenetic analysis of Erysimum using internal transcribed spacer (ITS) DNA sequences from c. 85% of the species (117 for the first time), representing the full range of morphological variation and geographical distribution. We used several approaches to reconstruct phylogenetic relationships, dating of diversification and patterns of evolution of morphological characters in the genus. Ancestral-state reconstructions of four morphological diagnostic characters were performed using maximum parsimony, maximum likelihood and Bayesian methods. Our phylogenetic framework strongly supports the monophyly of Erysimum and recovers some well-supported clades that are geographically, rather than morphologically, correlated. Our study confirms the placement of Erysimum in lineage I and reveals two Malcolmia spp. (M. maritima and M. orsiniana) as its sister taxa. The results suggest that the biennial duration and caespitose habit (vs. annual or perennial duration and herbaceous or woody habit) and large, yellow, glabrous (vs. small, non-yellow, pubescent) petals are ancestral in Erysimum. The ancestral-state reconstruction results show that annual vs. perennial and woody vs. herbaceous features have been independently derived several times. The dating analyses suggest an early radiation of Erysimum during the late Pliocene or early Pleistocene.
    Botanical Journal of the Linnean Society 01/2014; 175:497-522. · 2.59 Impact Factor
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    ABSTRACT: The Brassicaceae family (mustards or crucifers) includes Arabidopsis thaliana as one of the most important model species in plant biology and a number of important crop plants such as the various Brassica species (e.g. cabbage, canola, mustard). Moreover, the family comprises an increasing number of species that serve as study systems in many fields of plant science and evolutionary research. However, systematics and taxonomy of the family are very complex and access to scientifically valuable and reliable information linked to species and genus names and its interpretation are often difficult. BrassiBase is a continuously developing and growing knowledge database (http://brassibase.cos.uni-heidelberg.de) that aims at providing direct access to many different types of information ranging from taxonomy and systematics to phylo- and cytogenetics. Providing critically revised key information, the database intends to optimize comparative evolutionary research in this family and supports the introduction of the Brassicaceae as the model family for evolutionary biology and plant sciences. The new version 1.1.9. has now implemented some features that should help to accomplish these goals within a comprehensive taxonomic framework. A "phylogenetic placement tool" should help to identify critical accessions and germplasm and provide a first visualization of phylogenetic relationships. The "cytogenetics tool" provides in-depth information on genome sizes, chromosome numbers and polyploidy and sets this information into a Brassicaceae-wide context.
    Plant and Cell Physiology 11/2013; · 4.98 Impact Factor
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    ABSTRACT: Draba includes over 390 species distributed globally, mostly in extreme ecosystems at high elevations and latitudes making it the most successful and species-rich genus of the Brassicaceae, particularly in mountain and alpine regions. In this analysis, species richness data were collected from floras and checklists, and species distribution patterns were compared on a global scale for 367 of the species. A compilation of the geographical distribution of the entire genus using a presence/absence matrix was generated and displayed upon geographical maps. The three areas of highest species richness are the northern Andes (48 spp.), central Rocky Mountains (49 spp.), and Tibetan Plateau/C-SW Chinese (Hengduan) mountains (52 spp.). Previous phylogenetic analyses are in congruence with the area cladogram shown herein. It is shown that Draba has a diverse range of distribution patterns from widely spread to narrowly endemic. Species with wider distributions are frequently found in the Arctic, while those with a more narrow distribution are restricted to high elevations. However, ploidy-level information as well as recently presented genetic data convincingly indicates that the European and West Asian biota have served as a primary source and center of origin of the large diversity in the genus. A complete list of accepted Draba species is provided.
    Alpine Botany 09/2013; · 1.77 Impact Factor
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    ABSTRACT: Six new species of Brassicaceae (Brayopsis chacasensis Al-Shehbaz & A. Cano, Descurainia canoensis Al-Shehbaz, Draba canoensis Al-Shehbaz, Trinidad, Ed. Navarro & D. Rodr.-Paredes, D. punoensis Al-Shehbaz, Ed. Navarro, Trinidad & A. Cano, Neuontobotrys camanaensis Al-Shehbaz & A. Cano, and Weberbauera ayacuchoensis Al-Shehbaz, A. Cano & Trindad) are described and illustrated, and their distinguishing characters from nearest relatives are discussed. Brief notes on the diversity of these five genera in South America, especially Peru, are discussed.
    Kew Bulletin 06/2013; 68(2).
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    Taxon 04/2013; 62:343-356. · 2.78 Impact Factor
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    ABSTRACT: Boechera (Brassicaceae) is a diverse genus of ± 70 sexual diploid species and numerous apomictic hybrids concentrated in western North America. It is the largest genus in tribe Boechereae, which also includes seven other small genera. Boechera is closely related to Arabidopsis and is becoming a model genus for diverse studies, focusing particularly on apomixis and hybrid speciation. As part of an ongoing effort to clarify the taxonomy of the group, we present phylogenetic analyses of Boechereae, including all genera of the tribe and most of the sexual diploid species of Boechera. Ten loci are used, including two plastid loci, nrDNA ITS, and seven low-copy nuclear loci. These analyses indicate that Boechera, as currently circumscribed, is polyphyletic, comprising three main clades. Eastern North American species previously assigned to Boechera form a distinct clade with the Asian taxon Borodinia macrophylla and are herein transferred to the genus Borodinia, resulting in seven new combinations (Borodinia burkii, Borodinia canadensis, Borodinia dentata, Borodinia laevigata, Borodinia missouriensis, Borodinia perstellata, and Borodinia serotina). Boechera repanda, a morphologically aberrant species endemic to the Sierra Nevada, is recognized in the new genus Yosemitea (as Yosemitea repanda). A primarily western North American clade comprising all remaining species is strongly supported and retains the name Boechera. Although resolution within Boechera sensu stricto is limited, a number of well-supported clades are identified.
    Systematic Botany 03/2013; 38(1):192-209. · 1.29 Impact Factor
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    ABSTRACT: We are developing an online-accessible knowledge and database system of cross-referenced information and resources on Brassicaceae (Cruciferae) taxonomy, systematics and evolution, including chromosome numbers, traits and characters, germplasm resources, and accurate enumeration of all species, genera and tribes. Biological, molecular and evolutionary knowledge is exponentially increasing in the mustard family. However, because of the complex and overwhelming biological diversity of the family, it is difficult to assess research results within a larger evolutionary framework. Many species have proven to be remarkable study objects but are rarely available. Biological material and resources, either collected directly in the wild or held in germplasm collections, have often been taxonomically misidentified; and only very rarely has the material been further characterized and documented. There is also no comprehensive survey of character and trait distribution among Brassicaceae lineages, though family-wide phylogenies are meanwhile available. In order to close these gaps, we will make accessible to the scientific community the research data focusing on adaptive characters and their evolution in the Brassicaceae. In this context, we will also provide a comprehensive documentation of the taxonomy and systematics of the entire family. This will include a database with all relevant taxonomic, systematic and phylogenetic literature, a comprehensive data collection of characters and traits, a DNA-based identification tool for genera and species, electronic interactive keys for the identification of genera and species, and a setup of a carefully selected and documented germplasm collection representing main lineages of the family. This knowledge database, hereafter BrassiBase, has been launched within the framework of the DFG priority programme SSP 1529 “Adaptomics – Evolutionary plant solutions to ecological challenges/Molecular mechanisms underlying adaptive traits in the Brassicaceae s.l.”
    Taxon 10/2012; 61(5):1001-1009. · 2.78 Impact Factor
  • Ihsan A. Al-Shehbaz, Eduardo Navarro, Asunción Cano
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    ABSTRACT: A synopsis of the South American genus Aschersoniodoxa Gilg & Muschl. is presented, and the new species A. peruviana Al-Shehbaz, Eduardo Navarro & A. Cano is described and illustrated. An updated generic description of Aschersoniodoxa, a discussion of its tribal placement, and a key to its four species are given.
    Kew Bulletin 09/2012; 67(3).
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    ABSTRACT: Gametophytic apomixis is a common form of asexual reproduction in plants. Virtually all gametophytic apomicts are polyploids, and some view polyploidy as a prerequisite for the transition to apomixis. However, any causal link between apomixis and polyploidy is complicated by the fact that most apomictic polyploids are allopolyploids, leading some to speculate that hybridization, rather than polyploidy, enables apomixis. Diploid apomixis presents a rare opportunity to isolate the role of hybridization, and a number of diploid apomicts have been documented in the genus Boechera (Brassicaceae). Here, we present the results of a microsatellite study of 1393 morphologically and geographically diverse diploid individuals, evaluating the hypothesis that diploid Boechera apomicts are hybrids. This genus-wide dataset was made possible by the applicability of a core set of microsatellite loci in 69 of the 70 diploid Boechera species and by our ability to successfully genotype herbarium specimens of widely varying ages. With few exceptions, diploid apomicts exhibited markedly high levels of heterozygosity resulting from the combination of disparate genomes. This strongly suggests that most apomictic diploid Boechera lineages are of hybrid origin, and that the genomic consequences of hybridization allow for the transition to gametophytic apomixis in this genus.
    Evolution 04/2012; 66(4):985-95. · 4.86 Impact Factor
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    ABSTRACT: Parodiodoxa is a monotypic genus of Brassicaceae endemic to northwestern Argentina. It is poorly known and until now remained the only South American genus of the family that had not been assigned to a particular tribe. Sequence data from the nuclear ribosomal ITS region and the chloroplast trnL intron/trnL-F spacer region were used in this study to determine the systematic position of Parodiodoxa. For this purpose, taxa were sampled both at the tribal and generic levels. Results from tribal-level sampling support the inclusion of Parodiodoxa in the tribe Thelypodieae, whereas those at the generic level reveal a relationship to Weberbauera (W. rosulans and W. herzogii). Topologies within the Thelypodieae were poorly resolved, in agreement with previous studies. Morphological characteristics of Parodiodoxa are also discussed in relation to other genera of the tribe.
    Plant Systematics and Evolution 02/2012; 299(2). · 1.31 Impact Factor
  • Ihsan A. Al-Shehbaz
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    ABSTRACT: The new species Englerocharis dentata and Eudema peruviana are described, illustrated, and their relationships to nearest relatives are discussed. The former is readily distinguished from its other congeners by it broadly spatulate, 7–9-dentate leaves (vs. narrower, entire leaves). Eudema peruviana is the smallest plant in the genus and is hardly 1 cm tall and with linear, glabrous leaves, unbranched caudex without leaf remains, persistent sepals, and broadly globose, angustiseptate fruits. Keys to species of Englerocharis and to the Peruvian species of Eudema are given.
    Harvard Papers in Botany 01/2012;
  • Ihsan A Al-Shehbaz, Asunción Cano, Huber Trinidad
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    ABSTRACT: A synopsis of the largely Peruvian genus Englerocharis Muschl. is presented, and the new species E. ancashensis Al-Shehbaz, A. Cano & Trinidad is described and illustrated. An updated generic description of Englerocharis and a key to its four species are given. The generic differences between Englerocharis and Brayopsis Gilg & Muschl. are discussed.
    Kew Bulletin 01/2012; Kew Bulletin(67):1-5.
  • I. A. Al-Shehbaz, K. Mummenhoff
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    ABSTRACT: The genus Stubendorffia (Brassicaceae) is distinguished from Lepidium solely by the dehiscent vs. indehiscent angustiseptate fruits. By contrast, Winklera is separated from Lepidium by a combination of perennial habit, pinnatisect leaves, yellow flowers, and wingless fruits, characters all of which occur individually and in various combinations within Lepidium. Extensive molecular studies strongly show that Winklera and polyphyletic Stubendorffia are nested within the earlier-published Lepidium and, therefore, the three genera are herein formally united. The new name Lepidium pavlovii and 10 new combinations, L. afghanicum, L. apterum, L. botschantzevii, L. curvinervium, L. lipskyi, L. olgae, L. orientalis, L. patrinoides, L. pterocarpum, and L. silaifolium, are proposed. Lepidium apterum is lectotypified. A complete generic synonymy of Lepidium and an expanded generic description are presented.
    Edinburgh Journal of Botany 06/2011; 68(02):165 - 171.
  • Suzanne I. Warwick, Ihsan A. Al-Shehbaz, Connie A. Sauder
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    ABSTRACT: Sequence data from the nuclear ribosomal internal transcribed spacer (ITS) region of 45 taxa were used to determine the phylogenetic relationship of Arabis arenicola to Arabis, Arabidopsis, Braya, and Eutrema, and that of Eutrema to the purportedly related genera Aphragmus, Lignariella, Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella. Arabis arenicola was originally described as Eutrema in 1830, transferred to Arabis in 1898, and has remained in Arabis to the present, even though it is morphologically more similar to Arabidopsis, Braya, and Eutrema. Sequence data were obtained from representative taxa of Arabis, Arabidopsis, and related Boechera and Catolobus, Braya and Neotorularia, and Eutrema, Aphragmus, Lignariella, Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella. The five Arabis arenicola accessions examined had ITS sequences that were identical to each other and to four Arabidopsis lyrata accessions. In both maximum parsimony and maximum likelihood analyses, Arabis arenicola fell within the Arabidopsis clade and was closely aligned with Arabidopsis lyrata. Two of six purportedly related genera were not closely related to Eutrema. Both analyses placed Lignariella within a separate well-supported clade with Aphragmus, while the other four genera, Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella, fell within a well-supported clade with Eutrema. Morphology and molecular data strongly suggest transferring Arabis arenicola to Arabidopsis, expanding Aphragmus to include Lignariella, and expanding Eutrema to include Neomartinella, Platycraspedum, Taphrospermum, and Thellungiella. New combinations in Arabidopsis and Aphragmus are proposed.
    Canadian Journal of Botany 03/2011; 84(2):269-281. · 1.40 Impact Factor
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    ABSTRACT: Based on extensive molecular studies and critical evaluation of morphological characters, the tribe Stevenieae and the genus Pseudodraba are described as new to science. The Stevenieae include the genera Macropodium, Pseudoturritis, and Stevenia with a total of 11 species; a key separating these three genera is presented. Draba hystrix is placed in the monotypic Pseudodraba due to its morphological distinctness supported by molecular data. Arabis tenuisiliqua and A. tibetica are transferred to the genus Crucihimalaya. Three new combinations, i.e. Pseudodraba hystrix, Crucihimalaya tenuisiliqua, and C. tibetica are formed.
    Plant Diversity and Evolution. 03/2011; 129(1):71-76.
  • Ihsan A. Al-Shehbaz
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    ABSTRACT: A second species of the Chilean endemic Ivania, I. juncalensis, is described and illustrated. It is readily distinguished from the generic type I. cremnophila, which is also known only from the type collection, by its pinnatifid and oblong to lanceolate (vs. entire or dentate and cordate to subreniform) basal leaves, smaller flowers (ovate sepals 2.5–3 mm long and spatulate petals 6–7.5 × 2.5–3 mm vs. oblong sepals 5–6 mm long and broadly obovate petals 11–13 × 5–6 mm), and strongly 2-lobed (vs. entire) stigma.
    Harvard Papers in Botany 02/2011;

Publication Stats

1k Citations
132.53 Total Impact Points

Institutions

  • 2014
    • Instituto de Botánica Darwinion
      Darwin, Río Negro, Argentina
  • 2000–2014
    • Missouri Botanical Garden
      San Luis, Missouri, United States
  • 2010–2013
    • Universität Heidelberg
      • • Division of Biodiversity and Plant Systematics
      • • Centre of Organismal Studies (COS)
      Heidelburg, Baden-Württemberg, Germany
  • 2009
    • Universidad Nacional de La Pampa
      Pampa Almirón, Chaco, Argentina
    • Universität Osnabrück
      • Botanical Garden
      Osnabrück, Lower Saxony, Germany
    • University of San Diego
      San Diego, California, United States
  • 2006
    • New Mexico State University
      • Department of Biology
      Las Cruces, NM, United States