Latest Articles from PhytoKeys Latest 37 Articles from PhytoKeys https://phytokeys.pensoft.net/ Thu, 28 Mar 2024 22:53:30 +0200 Pensoft FeedCreator https://phytokeys.pensoft.net/i/logo.jpg Latest Articles from PhytoKeys https://phytokeys.pensoft.net/ Two new diatom species of the genus Gomphonemopsis (Bacillariophyceae) from the coast of China and two new combinations for the genus https://phytokeys.pensoft.net/article/114018/ PhytoKeys 239: 255-266

DOI: 10.3897/phytokeys.239.114018

Authors: Lang Li, Qun-Zhuan Nong, Chang-Ping Chen, Yu-Hang Li, Jun-Xiang Lai

Abstract: Two new diatom species belonging to the genus Gomphonemopsis are described, Gomphonemopsis nana sp. nov. and Gomphonemopsis gaoi sp. nov. These two species were compared in detail with congeners. Gomphonemopsis nana is distinguished by its high stria density and small size. This species was found so far to be epiphytic only on the eelgrass collected from Qingdao Bay (Yellow Sea). Gomphonemopsis gaoi is characterized by its isopolar valves, simple proximal raphe endings and acutely rounded apices. This taxon was separated from the exoskeleton of marine copepods sampled from the Futian Mangrove Nature Reserve (South China Sea). In addition, two new combinations, Gomphonemopsis oahuensis (Hustedt) Lang Li, Yuhang Li & Changping Chen, comb. nov. and Gomphonemopsis platypus (Østrup) Lang Li, Yuhang Li & Junxiang Lai, comb. nov. are proposed. This study increases the records and knowledge of Gomphonemopsis along the coast of China.

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Research Article Tue, 26 Mar 2024 19:41:03 +0200
A new freshwater species of Pinnularia (Bacillariophyta) from Hunan Province, China https://phytokeys.pensoft.net/article/116946/ PhytoKeys 237: 179-189

DOI: 10.3897/phytokeys.237.116946

Authors: San-Mei Xu, Bing Liu, Patrick Rioual, Man-Qi Yi, Yi-Dan Ma

Abstract: This study describes a new species of Pinnularia, P. hupingensis sp. nov., on the basis of light and scanning electron microscope images. Pinnularia hupingensis sp. nov. is characterised by its linear valve outline, extremely divergent striae, and very large hexagonal central area occupying ca. 1/5–1/8 of the valve length. The primary and secondary sides of the valve and the internal proximal raphe fissures are discussed. The new species is compared to similar taxa of the genus Pinnularia.

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Research Article Tue, 23 Jan 2024 14:44:10 +0200
A new species of genus Crenotia (Bacillariophyta) from Tibet, China https://phytokeys.pensoft.net/article/112939/ PhytoKeys 237: 23-35

DOI: 10.3897/phytokeys.237.112939

Authors: Xinyuan Na, Jiaming Liu, Ying Zhang, John Patrick Kociolek, Maxim Kulikovskiy, Xinxin Lu, Fengyang Sui, Huan Zhu, Guoxiang Liu, Yawen Fan, Yan Liu

Abstract: During the investigation of the freshwater diatoms from Tibet, a monoraphid species was observed from a hot spring near Anduo County, located on a plateau in the central portion of Tibet. This species shares the diagnostic features of Crenotia, such as the valve bent along the transapical axis, striae uniseriate to biseriate from centre to the apices and areolae with special structures located at the end of each stria. We compared the morphological characters of this new species with the others in this genus and show it to be new; it is named Crenotia tibetia sp. nov. This species has small valves with slightly protracted ends with nearly capitate apices, lanceolate axial area, central area unilaterally expanded to the margin, striae uniseriate to biseriate, but, in some valves, the striae are only uniseriate. Areolae are round small to irregular in shape and, at the end of each stria, there is a horseshoe-shaped areola present. Observations of developing valves show all the striae begin biseriate, then they become covered by silica to form uniseriate striae. Comparisons are made amongst the species in this genus and with genera assigned to the Achnanthidiaceae.

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Research Article Thu, 11 Jan 2024 18:59:30 +0200
Description of five new Luticola D.G.Mann (Bacillariophyta, Diadesmidaceae) species from Indonesia with comments on the morphological boundaries of the genus https://phytokeys.pensoft.net/article/113773/ PhytoKeys 237: 1-22

DOI: 10.3897/phytokeys.237.113773

Authors: Mateusz Rybak, Łukasz Peszek, Oktiyas Muzaky Luthfi, Sulastri Arsad, John Patrick Kociolek, Andrzej Witkowski

Abstract: During a survey of the Indonesian diatoms, five Luticola D.G.Mann taxa that could not be identified, based on the available literature were discovered. Based on light microscopy, scanning electron microscope observations and comparisons with similar taxa, all of them are described as new species. All taxa were found on mosses growing on tree trunks and concrete on the islands of Banda Besar and Seram and from spring on Java Island. Luticola insularis sp. nov. is most similar to L. aequatorialis and L. simplex, but it can easily be distinguished from both taxa, based on the lower striae density, the narrower valves and the well-developed silica ridges on the valve face/mantle junction. Luticola bandanensis sp. nov. resembles L. frequentissima, but they can be easily distinguished, based on their valve widths and the direction of the grooves located on the distal and proximal raphe endings. Luticola elliptica sp. nov. is most similar to L. sparsipunctata, L. tenuis and L. bryophila. Amongst all the species compared, L. elliptica sp. nov. is the only one with a highly asymmetrical central area, with the isolated pore located on the wider side. Luticola malukuana sp. nov. shares similarities with L. dismutica and L. areolata, but it has a notably higher stria density. From L. areolata, it can also be separated by the morphology of striae and the lack of ghost areolae in the central area. Luticola poliporea sp. nov. is unique in the whole genus due to the presence of multiple isolated pores.

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Research Article Fri, 5 Jan 2024 14:19:12 +0200
Craspedostauros nazmii sp. nov., a new diatom species (Bacillariophyta) from the Turkish Coast of the Black Sea https://phytokeys.pensoft.net/article/106545/ PhytoKeys 232: 77-88

DOI: 10.3897/phytokeys.232.106545

Authors: Elif Yılmaz, Andrzej Witkowski, Neslihan Özdelice, Cüneyt Nadir Solak, Romain Gastineau, Turgay Durmuş

Abstract: Craspedostauros E.J. Cox is a diatom genus comprising 17 taxa reported from various regions of the world. While many species of Craspedostauros are epibiontic, the taxa have variable ecological preferences. In this study we formally describe Craspedostauros nazmii sp. nov., an epilithic species discovered along the Turkish Black Sea Coast, based on light and scanning electron microscopy. Craspedostauros nazmii sp. nov. is characterized by valves that are lanceolate to narrowly lanceolate, slightly constricted near the apices with uniseriate, parallel throughout the whole valve, transapical striae and and the presence of an apical silica flap. The areolae are distributed over the valve face and the mantle. The differences and similarities between C. nazmii sp. nov. and established species of Craspedostauros are discussed. Based on shape and morphometrics, the most similar species is Craspedostauros capensis, but it is easily distinguished from C. nazmii sp. nov. by its lack of an apical silica flap.

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Research Article Mon, 11 Sep 2023 10:29:22 +0300
Seven Epithemia taxa (Bacillariophyta) from Lake Akan (Japan) and their salinity tolerances https://phytokeys.pensoft.net/article/104449/ PhytoKeys 229: 139-155

DOI: 10.3897/phytokeys.229.104449

Authors: Takashi Chiba, Yoshifumi Horie, Akihiro Tuji

Abstract: The ecologies (salinity tolerance) of many diatoms are largely unknown, despite their potential to contribute to more detailed paleoenvironmental reconstructions. This study therefore aimed to investigate the relationship between diatom species and salinity. We cultured seven cosmopolitan benthic diatom species obtained from Lake Akan, a freshwater inland lake in Japan: Epithemia adnata, E. frickei, E. gibba, E. operculata, E. sorex, E. sp. and E. turgida. Each species was cultured at eleven salinities between 0‰ and 50‰. Epithemia adnata, E. frickei and E. sorex had the highest growth rate at a salinity of 3‰, with no further increase observed above 25‰. However, E. gibba had the highest growth rate at a salinity of 5‰, with no increase at salinities ≥ 30‰. These results suggest that E. adnata, E. frickei, E. gibba, and E. sorex grow in freshwater to brackish-water environments. Epithemia operculata and E. sp. proliferated at all salinities, indicating that they can adapt to hypersaline environments. However, E. turgida did not survive in salinities >10‰, making it the species with the narrowest salinity tolerance range. These results provide new knowledge that improves the understanding of the ecology of these species in modern environments and offer insights into paleoenvironmental reconstructions through diatom analysis.

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Research Article Tue, 18 Jul 2023 18:05:41 +0300
The diatom genus Ulnaria (Bacillariophyta) in China https://phytokeys.pensoft.net/article/101080/ PhytoKeys 228: 1-118

DOI: 10.3897/phytokeys.228.101080

Authors: Bing Liu

Abstract: This study deals with Ulnaria species found and described from two regions of China with large climate differences during the period of 2014–2022. The first region, located in the Wuling Mountains and Hunan province, has a subtropical climate and the second in Qinghai, a northwest province of China, has a highland continental climate which is characterized by a cold and long winter and warm, short summer. Previously there were nine new Ulnaria species published from the first region. This study describes 14 additional new Ulnaria taxa, nine of which were found in the first region and five of which were found in the second region. A key to the Ulnaria species that have been described from China is provided. The main morphological characteristics for 63 Ulnaria taxa are summarized in Appendices which allow the division of these Ulnaria taxa into three groups: the seven members of group one all possess both uniseriate striae and valve marginal spines, the 42 members of group two all possess uniseriate or mostly uniseriate striae but without the valve marginal spines, and the 14 members of group three all possess mostly biseriate striae and without valve marginal spines. To summarize the morphological characters of the published Ulnaria taxa and 14 taxa described in this study several conclusions for the characterization of Ulnaria are drawn: 1) each cell has two valve-appressed, long plate-like plastids; 2) living cells of many Ulnaria species often lie in girdle view on a slide because they have deep mantles and some copulae associated with either the epivalve or the hypovalve so that the cell depth is often larger than the valve width; 3) the basic structures forming a valve include sternum, virgae, and vimines/viminules; 4) the valvocopula is a closed hoop which has a similar ultrastructure in all Ulnaria taxa but differs from the other copulae in structure; 5) the configuration of girdle bands is a common condition; 6) the life history of Ulnaria can be divided into the four series of successive stages: auxospore, initial cell, pre-normal vegetative cell, and normal vegetative cell, which is very similar to the life history of Hannaea inaequidentata (Lagerstedt) Genkal and Kharitonov; 7) the closed valvocopula is proposed as a definition character for the genus Ulnaria because demonstrating all girdle bands closed is impracticable.

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Monograph Fri, 23 Jun 2023 18:25:40 +0300
Morphology and molecular phylogeny of Pleurosigma pacificum sp. nov. (Pleurosigmataceae), a new tropical pelagic species from the Western Pacific Ocean https://phytokeys.pensoft.net/article/103890/ PhytoKeys 227: 99-108

DOI: 10.3897/phytokeys.227.103890

Authors: Fei-Chao Du, Yu-Hang Li, Kui-Dong Xu

Abstract: A new species of pelagic diatom, Pleurosigma pacificum sp. nov., is described from the tropical Western Pacific Ocean. It has the typical features of Pleurosigma, including a slightly sigmoid raphe, intersected transverse and oblique striae, and loculate areolae with external opening slits and internal poroids. Morphologically, P. pacificum belongs to a species group of Pleurosigma with lanceolate valves, including P. atlanticum Heiden & Kolbe, P. nubecula W. Smith, P. indicum Simonsen, and P. simonsenii Hasle. However, P. pacificum differs by its smaller lanceolate valve and smaller intersection angle as well as elliptical areolae without a silica bar. The SSU rDNA and rbcL sequence data place P. pacificum in a basal position relative to other species of Pleurosigma. Our molecular phylogenetic analyses did not support the monophyly of lanceolate and slightly sigmoid species. Thus, the sigmoidality of valve outline cannot be considered as a criterion to define the species group.

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Research Article Fri, 2 Jun 2023 18:42:28 +0300
Checklist of the diatoms (Bacillariophyta) from Lake Naivasha, Kenya, with some historical notes https://phytokeys.pensoft.net/article/98168/ PhytoKeys 224: 101-174

DOI: 10.3897/phytokeys.224.98168

Authors: Christine Cocquyt, Dirk Verschuren

Abstract: Lake Naivasha is one of only two large freshwater lakes in the Eastern Rift Valley of Kenya, East Africa. Together with its satellite lakes Crescent Island Crater, Oloidien and Sonachi, it comprises a great variety of pelagic and benthic habitats for aquatic biota, and its sediment record represents a unique archive of past climate change and long-term ecosystem dynamics in equatorial East Africa. This is particularly so because local paleoenvironmental reconstructions can be checked against historical data on the composition of aquatic fauna and flora collected in Lake Naivasha since the early 20th century. Some of the most prominent biological proxies for reconstructing past changes in lakes are diatoms (Bacillariophyta), a group of unicellular autotrophic eukaryotes of which the siliceous skeletons (valves) preserve well in lake sediments and are good indicators for, among others, climate-driven changes in salinity. However, diatom taxonomy and species concepts have changed a lot in recent decades, making it sometimes difficult for non-taxonomists to know which species are concerned in different published studies. This paper provides the currently accepted taxonomic names of the 310 specific and infraspecific diatom taxa reported from Lake Naivasha and its satellite lakes to date, together with their synonyms used in literature concerning these lakes as well as other, commonly used synonyms. Further, a short overview is given of the history of diatom research conducted on materials from Lake Naivasha and its satellite lakes. The present checklist may facilitate the identification and interpretation aspects of future diatom studies on the wider Lake Naivasha ecosystem and on other East African lakes that are less well studied.

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Checklist Fri, 7 Apr 2023 17:47:17 +0300
Diatoma sinensis: a new diatom species (Bacillariophyta) found in the brackish Lake Qinghai, China https://phytokeys.pensoft.net/article/90438/ PhytoKeys 210: 93-108

DOI: 10.3897/phytokeys.210.90438

Authors: Li Yuan, Bing Liu, Patrick Rioual, Ji-Yan Long, Yu-Mei Peng

Abstract: Lake Qinghai is an ancient brackish water lake in which several endemic diatom species have been discovered. In this study, a species of Diatoma is observed under light and scanning electron microscopy and described as new, Diatoma sinensis sp. nov. The living cells of D. sinensis always lie in girdle view due to the cell depth being much larger than valve width (3.3–8.8 vs. 2.0–3.0 μm). The valves of D. sinensis are characterized by their narrow, linear-lanceolate outline, with capitate to subcapitate apices, the presence of two rimoportulae, one at each apex, embedded in the last rib or located among striae and a 4:2 configuration of girdle bands in normal vegetative cells, with four bands assigned to the epivalve and two to the hypovalve. The new taxon is compared with similar species from the genera Diatoma and Distrionella.

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Research Article Wed, 5 Oct 2022 18:03:30 +0300
A new marine epipsammic diatom species, Ambo dajingensis sp. nov. (Bacillariophyceae), from the coast of Southeast China https://phytokeys.pensoft.net/article/90876/ PhytoKeys 210: 23-34

DOI: 10.3897/phytokeys.210.90876

Authors: Honghan Liu, Zhen Wang, Weiwei Wu, Chenhong Li, Jiawei Zhang, Yahui Gao, Xuesong Li, Lin Sun, Junrong Liang, Jun Zhang, Changping Chen

Abstract: Ambo dajingensis HH Liu, Z Wang, YH Gao & CP Chen, sp. nov. is described as a new species in samples collected from sand grains at Dajing Beach, Ningde City, Fujian Province, China. Morphological details of the new species with respect to valve shape, size and valve ultrastructure are presented based on light microscopy (LM) and scanning electron microscopy (SEM). The main features of Ambo dajingensis under a light microscope are elongated elliptic valves with rounded apices, two internal costae on the valve and rectangular in girdle views. SEM observation showed that externally, the frustules are comprised of two valves with a relatively deep mantle and a transition between the valve faces. Small, flabelliform spines are present along the valve margin. Internally, the valves are divided into three sectors by robust costae, which penetrate the whole valve lumen and are thickest at the mantle interior and thinner toward the center. The sternum is narrow and linear, visible only in the valve apex, set off by costae. The striae are comprised of small, round areolae and they are parallel in the middle to slightly radiate at the apices. The new species is compared with other species in the genus Ambo.

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Research Article Wed, 28 Sep 2022 10:47:38 +0300
Revision of Ardissoneaceae (Bacillariophyta, Mediophyceae) from Micronesian populations, with descriptions of two new genera, Ardissoneopsis and Grunowago, and new species in Ardissonea, Synedrosphenia and Climacosphenia https://phytokeys.pensoft.net/article/89913/ PhytoKeys 208: 103-184

DOI: 10.3897/phytokeys.208.89913

Authors: Christopher S. Lobban, Matt P. Ashworth, Terance Camacho, Daryl W. Lam, Edward C. Theriot

Abstract: Ardissonea was resurrected from Synedra in 1986 and was included as a genus by Round, Crawford and Mann (“The Diatoms”) in its own Family and Order. They commented that there might be several genera involved since the type species of the genus possesses a double-walled structure and other taxa placed in Ardissonea have only a single-walled structure. Two other genera of “big sticks,” Toxarium and Climacosphenia, were placed in their own Families and Orders but share many characters with Ardissoneaceae, especially growth from a bifacial annulus. Eighteen taxa (11 new species) from Micronesia were compared with the literature and remnant material from Grunow’s Honduras Sargassum sample to address the concepts of Ardissonea and Ardissoneaceae. Phylogenetic and morphological analyses showed three clades within Ardissonea sensu lato: Ardissonea emend. for the double-walled taxa, Synedrosphenia emend. and Ardissoneopsis gen. nov. for single-walled taxa. New species include Ardissonea densistriata sp. nov.; Synedrosphenia bikarensis sp. nov., S. licmophoropsis sp. nov., S. parva sp. nov., and S. recta sp. nov.; Ardissoneopsis fulgicans sp. nov., A. appressata sp. nov., and A. gracilis sp. nov. Transfers include Synedrosphenia crystallina comb. nov. and S. fulgens comb. nov. Synedra undosa, seen for the first time in SEM in Grunow’s material, is transferred to Ardissoneopsis undosa comb. nov. Three more genera have similar structure: Toxarium, Climacosphenia and Grunowago gen. nov., erected for Synedra bacillaris and a lanceolate species, G. pacifica sp. nov. Morphological characters of Toxarium in our region support separation of Toxarium hennedyanum and T. undulatum and suggest additional species here and elsewhere. Climacosphenia moniligera was not found but we clarify its characters based on the literature and distinguish C. soulonalis sp. nov. from it. Climacosphenia elongata and a very long, slender C. elegantissima sp. nov., previously identified as C. elongata, were present along with C. scimiter. Morphological and molecular phylogenetics strongly suggested that all these genera belong in one family and we propose to include them in the Ardissoneacae and to reinstate the Order Ardissoneales Round.

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Monograph Wed, 21 Sep 2022 14:42:34 +0300
A new freshwater species Achnanthidium kangdingnese (Bacillariophyta, Achnanthidiaceae) from Sichuan Province, China https://phytokeys.pensoft.net/article/89690/ PhytoKeys 204: 97-108

DOI: 10.3897/phytokeys.204.89690

Authors: Pan Yu, Qingmin You, Yonghong Bi, Quanxi Wang

Abstract: A new freshwater diatom species, Achnanthidium kangdingnese Yu, You & Wang, sp. nov. from Sichuan Province, China, is described. The morphology of this species was analyzed with scanning electron microscopy (SEM) and light microscopy (LM). A. kangdingnese belongs to the A. initium-like subgroup, which has external distal raphe ends curved in opposite directions of the valve. The main characteristics of A. kangdingnese are its linear shape, rounded apices and transpically-elongated areolae on the both valves. The central area is well defined with one or two spaced striae of the raphe valve. And on the internal valve, areolae are occluded by hymens perforated by delicate slits, and each hymen is closely joined with the adjacent hymen. We compared the new species with other similar species of Achnanthidium, A. kangdingnese is considered to be sufficiently different from other similar species based on valve outline, shape of the axial and center areas, and striae density. The new species is known only from its type locality, a mountain lake in Kangding County.

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Research Article Fri, 12 Aug 2022 19:16:18 +0300
Two new freshwater species of Surirella (Bacillariophyta) from the Wuling Mountains, China https://phytokeys.pensoft.net/article/79626/ PhytoKeys 201: 35-49

DOI: 10.3897/phytokeys.201.79626

Authors: Ji-Yan Long, John Patrick Kociolek, David M. Williams, Bing Liu, Wen-Hui Mo, Jin-Hua Chen

Abstract: Two sympatric Surirella species found at the same specific locality in the Wuling Mountains of China are documented with light and scanning electron microscope. Both species are new to science and named S. wufluminensis sp. nov. and S. suiningensis sp. nov. Surirella wufluminensis has large frustules that are either clockwise or counterclockwise twisted when viewed with the light microscope, and possesses distinctive fibulae, mound-like outgrowths on the valve surface throughout, raised longitudinal ridges on both sides of the raphe, and two helictoglossa-like processes at one apex internally. Surirella suiningensis has narrowly ovate valve outline, distinctive fibulae, troughs alternating with crests from pole to pole, and two helictoglossa-like processes at one apex internally. These two species do not produce costae on the valve surface in contrast to many species in Surirella. This study provides a further two examples of the wide range of morphological diversity in the genus Surirella.

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Research Article Mon, 20 Jun 2022 18:02:38 +0300
Two new Halamphora (Bacillariophyta) species from the marine coasts off Livingston Island, Antarctica https://phytokeys.pensoft.net/article/81632/ PhytoKeys 195: 161-174

DOI: 10.3897/phytokeys.195.81632

Authors: Ralitsa Zidarova, Plamen Ivanov, Nina Dzhembekova, Myriam de Haan, Bart Van de Vijver

Abstract: During a survey of the marine benthic diatom flora on the coasts off Livingston Island (South Shetland Islands, Maritime Antarctic Region), two Halamphora species that could not be identified based on the currently available literature, were observed. Detailed light and scanning electron microscopy observations and thorough comparison with similar taxa in the literature revealed that both taxa should be described as new species. The first taxon, Halamphora kenderoviana sp. nov., was most likely misidentified in past Antarctic studies, and included within the range of another taxon, Halamphora coffeaeformis. Analysis of literature data showed that the second new taxon, Halamphora moncheviana sp. nov., has been previously reported from the Antarctic Continent (but as an unidentified species). The new taxa are compared with similar Halamphora taxa worldwide. Data on their ecology and distribution are also provided.

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Research Article Wed, 11 May 2022 11:48:33 +0300
Two new freshwater species of the genus Achnanthidium (Bacillariophyta, Achnanthidiaceae) from Qingxi River, China https://phytokeys.pensoft.net/article/78489/ PhytoKeys 192: 11-28

DOI: 10.3897/phytokeys.191.78489

Authors: Pan Yu, Qingmin You, Wanting Pang, Quanxi Wang

Abstract: We describe two new Achnanthidium species, A. anhuense sp. nov. and A. qingxiense sp. nov., from Qingxi River, Anhui Province, China, based on light and scanning electron microscopy. Both species belong to the “A. pyrenaicum complex” of the Achnanthidium genus, based on their possession of transapically-elongated areolae and deflected external distal raphe fissures. A. anhuense sp. nov. has a slightly irregular linear-lanceolate valve with rounded or weakly protracted apices and a transapically rectangular or bow tie central area on the raphe valve. A. qingxiense sp. nov. has a linear-lanceolate valve with rounded apices and the axial area distinct expanded apices on the rapheless valve. Both species differ sufficiently from other similar species, based on valve outline, shape of the axial and central areas and striae density. These new species were all collected from stone substratum.

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Research Article Fri, 4 Mar 2022 16:33:28 +0200
Two new species of Navicula (Bacillariophyta) from Southeast Asia https://phytokeys.pensoft.net/article/78164/ PhytoKeys 190: 69-85

DOI: 10.3897/phytokeys.190.78164

Authors: Maxim S. Kulikovskiy, Dmitry A. Chudaev, Anton M. Glushchenko, Irina V. Kuznetsova, John Patrick Kociolek

Abstract: We present light and scanning electron microscopical observations on two new species of Navicula Bory sensu stricto from Southeast Asia. Navicula winoniformis Chudaev, Glushchenko, Kulikovskiy & Kociolek, sp. nov. differs from taxa with similar outline and size by the combination of simple drop-like external raphe endings deflected to the primary valve side, presence of well-developed external longitudinal grooves and relatively low lineolae density. Navicula sparsilineolata Chudaev, Glushchenko, Kulikovskiy & Kociolek, sp. nov. can be discriminated from the taxa of similar valve shape and size by consistently lower lineolae density, and from the majority of them also by the structure of external proximal raphe endings with small projections in proximal parts and larger triangular insertions in distal parts. Some remarks on Navicula species diversity and its distribution in the Southeast Asia are given.

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Research Article Fri, 18 Feb 2022 10:50:28 +0200
Ultrastructure of three Species of Entomoneis (Bacillariophyta) from Lake Qinghai of China, with reference to the external areola occlusions https://phytokeys.pensoft.net/article/78149/ PhytoKeys 189: 29-50

DOI: 10.3897/phytokeys.189.78149

Authors: Ji-Yan Long, David M. Williams, Bing Liu, Wen-Hui Mo, Si-Jin Quan

Abstract: Three sympatric Entomoneis species, found at the same specific locality in Lake Qinghai, China, are studied by using light and scanning electron microscope. Two species are proposed as new to science and named as E. sinensis sp. nov. and E. qinghainensis sp. nov. The third species is identified as E. paludosa (W. Smith) Reimer. Entomoneis sinensis has a linear-lanceolate valve outline and Ƨ-shaped keel, bears two distinct 8-shaped loops formed by the valvocopula pars media in each cell and each of its stria is composed of either a long hymen strip or a long hymen strip plus one separated areola close to the raphe. Its hymen strip belongs to Type Two, which is a siliceous membrane strip perforated by two rows of linear pores next to transapical costae and two rows of rounded pores between these two rows of linear pores. Entomoneis qinghainensis has large cells, very high keel and evident hymen strip regions like a U-shaped neck pillow at the middle of valve face. Its hymen strip belongs to Type One, which is a siliceous membrane strip perforated by irregularly distributed round pores. Entomoneis paludosa also has the hymen strip regions that are worm-like and close to the raphe canal. Its hymen strip is same as that of E. qinghainensis. The two kinds of the outside areola occlusions in Entomoneis are compared, summarised and discussed.

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Research Article Tue, 25 Jan 2022 10:49:47 +0200
Achnanthidium bratanense sp. nov. (Bacillariophyceae, Achnanthidiaceae), a new diatom from the Lake Bratan (Bali, Indonesia) https://phytokeys.pensoft.net/article/77882/ PhytoKeys 188: 167-175

DOI: 10.3897/phytokeys.188.77882

Authors: Dmitry A. Kapustin, Anton M. Glushchenko, Maxim S. Kulikovskiy

Abstract: A new species, Achnanthidium bratanense, is described from Lake Bratan, located on the island of Bali (Indonesia). The morphology of this species was analyzed with light (LM) and scanning electron microscopy (SEM). A. bratanense is characterized by linear-elliptic to nearly elliptic valves with convex margins and rounded, broadly subcapitate apices. The striae of this species are hardly discernable under LM; they are weakly radiate throughout the valve and composed of one to four large transapically elongated areolae of different length and shape. The most similar taxon to A. bratanense is A. macrocephalum, a species described from Sumatra, another Indonesian island. The differences of A. bratanense from similar taxa are discussed.

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Research Article Fri, 21 Jan 2022 10:50:54 +0200
Achnanthidium gladius sp. nov. (Bacillariophyceae) – a new monoraphid diatom species from Indonesia https://phytokeys.pensoft.net/article/73913/ PhytoKeys 187: 129-140

DOI: 10.3897/phytokeys.187.73913

Authors: Natalia D. Tseplik, Yevhen I. Maltsev, Anton M. Glushchenko, Irina V. Kuznetsova, Sergei I. Genkal, Evgeniy S. Gusev, Maxim S. Kulikovskiy

Abstract: A new monoraphid diatom species Achnanthidium gladius sp. nov. is described from Indonesia. The description is based on molecular data (18SV4), morphological analysis and comparison with similar species. According to molecular data, Achnanthidium gladius sp. nov. is closely related to Achnanthidium minutissimum. Morphologically, the new species differs from similar species by the absence of a fascia on raphe valve, cell size, and striae density and pattern. The new species is only known from the type locality in Indonesia. Comparison with close related species is given.

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Research Article Fri, 17 Dec 2021 11:03:15 +0200
New and poorly known “araphid” diatom species (Bacillariophyta) from regions near Lake Titicaca, South America and a discussion on the continued use of morphological characters in “araphid” diatom taxonomy https://phytokeys.pensoft.net/article/73338/ PhytoKeys 187: 23-70

DOI: 10.3897/phytokeys.187.73338

Authors: Eduardo A. Morales, Carlos E. Wetzel, Luc Ector

Abstract: Based on two Andean Altiplano samples and on light and scanning electron microscopy analyses, we present six new species of “araphid” diatoms in the genus Pseudostaurosira, P. aedes sp. nov., P. frankenae sp. nov., P. heteropolaris sp. nov., P. oblonga sp. nov., P. occulta sp. nov., and P. pulchra sp. nov. Additional data are provided for four other known taxa, Nanofrustulum cataractarum, N. rarissimum, P. sajamaensis and P. vulpina, the latter species corresponding to a stat. nov. based on a variety of P. laucensis. Each taxon is described morphologically and compared with closely related published taxa, using characters such as axial area, virgae, vimines, areolar shape, volae, internal striae depositions, spines, flaps and apical pore fields, which are not usually used for species distinction within the genus. It is our intention that the detailed morphological descriptions of each taxon and the elaborate comparative tables we provide serve as a basis for correction of neo and paleo-databases for the Altiplano to produce a better account of autecological data and ecological change in the region. Some arguments for our continued use of a morphologically based approach are given in the context of rapid environmental degradation in the Andes and the difficulties in applying molecular approaches in countries such as Bolivia.

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Research Article Mon, 13 Dec 2021 16:00:04 +0200
Marine and brackish Luticola D.G.Mann (Bacillariophyta) species from the Java Sea and South China Sea coasts with the description of three new species https://phytokeys.pensoft.net/article/71049/ PhytoKeys 183: 115-142

DOI: 10.3897/phytokeys.183.71049

Authors: Mateusz Rybak, Andrzej Witkowski, Łukasz Peszek, John P. Kociolek, Yenny Risjani, Duc Hung Nguyen, Jinpeng Zhang, Yunianta, Van Duy Nguyen, Romain Gastineau, Thi Thuy Duong, Philippe Rosa, Vona Meleder

Abstract: In this study, samples were collected from the Java Sea coasts, from the South China Sea in Hainan Island coasts and Quảng Yên region and Rú Chá mangrove near Hue in Central Vietnam. In studied samples a total of eight Luticola species have been observed. Three of the taxa studied are described herein as species new to science – Luticola orientalis sp. nov., L. cribriareolata sp. nov. and L. halongiana sp. nov. Under light microscopy (LM) L. orientalis sp. nov. and L. cribriareolata sp. nov. are similar with rhombic-lanceolate to rhombic/ elliptic-lanceolate to elliptic valve shapes and narrowly rounded apices. Both species can be easily distinguished by stria density (higher density in L. orientalis). Under SEM L. cribriareolata is characterized by cribrate areola occlusions, a character thus far observed only in three established species. The remaining species of the whole genus known thus far are characterized by hymenate areola. Similar morphology Luticola species have been observed from tropical mangrove forests from Madagascar but they all can be easily distinguished based on the lack of grooves in the central area. The third species – L. halongiana sp. nov. has rhombic-elliptic to rhombic-lanceolate valves with broadly rounded to slightly protracted apices in larger specimens. This species has a relatively broad central area. Also unique among brackish-water Luticola is the small, rounded stigma positioned almost midway between the valve center and valve margin. In the habitats from which the new species are described we also identified five established Luticola taxa including, L. belawanensis, L. celebesica, L. inserata, L. seposita and L. tropica. For those species we provide detailed SEM characteristics of valve ultrastructure, as well as the range of environmental conditions and geographic distribution within the study area.

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Research Article Fri, 22 Oct 2021 17:20:05 +0300
Cymbopleura natellia – a new species from Transbaikal area (Russia, Siberia) described on the basis of molecular and morphological investigation https://phytokeys.pensoft.net/article/72285/ PhytoKeys 183: 95-105

DOI: 10.3897/phytokeys.183.72285

Authors: Anton Glushchenko, Evgeniy Gusev, Yevhen Maltsev, John Patrick Kociolek, Irina Kuznetsova, Maxim Kulikovskiy

Abstract: A new cymbelloid diatom species from the genus Cymbopleura (Krammer) Krammer is described on the basis of molecular and morphological investigations. Cymbopleura natellia Glushchenko, Kulikovskiy & Kociolek, sp. nov. is, on the basis of results with molecular data, close to C. naviculiformis (Auerswald ex Heiberg) Krammer. The two species differ both by molecular distance and morphological features. Morphologically, C. natellia sp. nov. is compared with several other species in the genus. This work is a pioneer investigation of cymbelloid taxa using molecular tool from Transbaikal area.

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Research Article Tue, 19 Oct 2021 10:20:17 +0300
Description of four new terrestrial diatom species from Luticola and Microcostatus genera from South Africa https://phytokeys.pensoft.net/article/65326/ PhytoKeys 182: 1-26

DOI: 10.3897/phytokeys.181.65326

Authors: Mateusz Rybak, Natalia Kochman-Kędziora, Łukasz Peszek

Abstract: The knowledge about terrestrial diatom assemblages in southern Africa is rather limited, despite a long history of diatom research in this area. Terrestrial habitats are places of characteristic diatom floras, dominated by species resistant to desiccation which are able to thrive in conditions of limited water availability. The presented work expands the knowledge about these unique habitats. During the study on terrestrial moss-inhabiting diatoms from Western Cape Province (South Africa), four taxa with a unique set of valve features have been found and described herein as new species, based on light and scanning electron microscopy. These new species are: Luticola microcephala M. Rybak, Peszek & Kochman-Kędziora, sp. nov., Luticola asymmetrica M. Rybak, Kochman-Kędziora & Peszek, sp. nov., Luticola terrestris Kochman-Kędziora, M. Rybak & Peszek, sp. nov. and Microcostatus meridionalis Peszek, M. Rybak & Kochman-Kędziora, sp. nov. Algal community composition had low species richness (9–15 taxa per sample) and samples were dominated by: Humidophila contenta, Nitzschia brevissima and Eunotia aff. pseudominor. The three new Luticola species formed numerous populations, exceeding 10% of the share, whereas Microcostatus meridionalis reached 5.4%. Basic morphological data of associated diatom flora together with detailed micrographs are also provided.

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Research Article Tue, 14 Sep 2021 15:47:43 +0300
Centric diatom diversity in the lower part of the Southern Bug river (Ukraine): the transitional zone at Mykolaiv city https://phytokeys.pensoft.net/article/64426/ PhytoKeys 178: 31-69

DOI: 10.3897/phytokeys.178.64426

Authors: Olena P. Bilous, Sergey I. Genkal, Jonas Zimmermann, Wolf-Henning Kusber, Regine Jahn

Abstract: The diversity of centric diatoms is documented for the transitional zone of the lower part of the Southern Bug River (Ukraine) just before entering the Dnipro-Bug Estuary and compared to earlier results from the upstream sampling sites of the same river system. Benthic samples of the following sites were investigated: north of Mykolaiv City (approximately 5 km), in Mykolaiv City (near Varvarivskyi Bridge), and 5 km south of the city. Twenty-four centric diatom taxa belonging to 11 genera were identified, analysed, and documented by scanning electron microscopy (SEM) and light microscopy (LM). Among them, Aulacoseira nivalis is the first report for Ukraine, A. islandica and is the first confirmed record for the studied area since the 1930s. The maximum number of centric diatom taxa found in one station was 21, the minimum 10. Melosira subglobosa was the most common (documented in 57–80% of sites with centric diatoms) and abundant species 7.3–15.7% in relative abundance to all diatom taxa. The discovered diversity of taxa and its comparison with previous results is discussed with regard to the relevance of estuary zones in the research of diatoms.

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Research Article Thu, 20 May 2021 11:16:19 +0300
Encyonopsis indonesica sp. nov. (Bacillariophyceae, Cymbellales), a new diatom from the ancient lake Matano (Sulawesi, Indonesia) https://phytokeys.pensoft.net/article/61044/ PhytoKeys 175: 1-11

DOI: 10.3897/phytokeys.175.61044

Authors: Dmitry A. Kapustin, Anton M. Glushchenko, John P. Kociolek, Maxim S. Kulikovskiy

Abstract: A new species, Encyonopsis indonesica, is described from the ancient lake Matano, Sulawesi island, Indonesia. The morphology of this species was studied by means of light and scanning electron microscopy. E. indonesica has a remarkable valve ultrastructure. The valve surface is ornamented with numerous longitudinal siliceous ribs and siliceous verrucae. Valve face delineated from the mantle by a thickened marginal ridge. Raised sterna border the raphe branches. Raphe is distinctly undulate with distal ends hooked strongly to the ventral side. The only similar species to E. indonesica is Amphora dissimilis described from New Caledonia. Comparison of both taxa is given and A. dissimilis is transferred to Encyonopsis. The taxonomic placement of both taxa is evaluated, and the phenomenon of external siliceous ornamentation is discussed.

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Research Article Wed, 17 Mar 2021 12:22:48 +0200
Achnanthidium tinea sp. nov. – a new monoraphid diatom (Bacillariophyceae) species, described on the basis of molecular and morphological approaches https://phytokeys.pensoft.net/article/60337/ PhytoKeys 174: 147-163

DOI: 10.3897/phytokeys.174.60337

Authors: Natalia D. Tseplik, Yevhen I. Maltsev, Anton M. Glushchenko, Irina V. Kuznetsova, Sergei I. Genkal, John Patrick Kociolek, Maxim S. Kulikovskiy

Abstract: A new monoraphid diatom species Achnanthidium tinea Tseplik, Kulikovskiy, Kociolek & Maltsev, sp. nov. is described from Indonesia. The species is described on the basis of molecular and morphological analyses. According to molecular data the new species belongs to the clade that includes strains of Achnanthidium minutissimum, Achnanthidium saprophilum and Achnanthidium digitatum. Morphologically, the new species differs quite significantly from other species of the same genus because of linear-elliptic valves with almost parallel sides and strongly radiate striae and a butterfly-shaped fascia on the raphe valve. The morphology and phylogeny of the new species are discussed, and thoughts on the current state of the taxonomy of the genus Achnanthidium are expressed. Our work shows the importance of using molecular data in diatom systematics and also demonstrates the need to investigate rarely studied regions of our planet.

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Research Article Fri, 12 Mar 2021 11:23:25 +0200
From chaos to order: the life history of Hannaea inaequidentata (Lagerstedt) Genkal and Kharitonov (Bacillariophyta), from initial cells to vegetative cells https://phytokeys.pensoft.net/article/56136/ PhytoKeys 162: 81-112

DOI: 10.3897/phytokeys.162.56136

Authors: Bing Liu, David M. Williams

Abstract: This study presents observations on three species of Hannaea and documents and illustrates the life history of H. inaequidentata. We have divided the life history of H. inaequidentata into the following four series of successive stages: auxospore, initial cell, pre-normal vegetative cell, and normal vegetative cell. The initial cell has a cylinder-like and a frequently twisted outline, a longitudinal perizonium wholly covering the valve surface, and a disc-shaped incunabular scale, but lacks any transverse perizonium bands. The pre-normal vegetative cell cannot form ribbon-like colonies, has a wide variety of irregular outlines and is composed of two cell types: one with its epivalve composed of either the initial epivalve or the initial hypovalve, its hypovalve being newly formed, the other with both its epivalve and hypovalve newly formed. The normal vegetative cell has a regular outline and exhibits a significant length reduction so that the largest valve is at least four times longer than the smallest. From initial cell to normal vegetative cell, the developmental sequence goes from ‘chaos to order’ as happens in many phenomena in the universe. The lack of transverse perizonium bands may be the cause of the initial ‘chaos’ process during its developing period from the initial cell to the normal vegetative cell. The development of frustule/valve shape, central area, sternum, virga, vimine, rimoportula and ocellulimbus etc. during the life circle is summarised. In the genus Hannaea, some taxa lack the strongly buttressed central area as in H. inaequidentata, which also has almost parallel valve margins.

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Research Article Fri, 9 Oct 2020 09:59:07 +0300
Four new species from the diatom (Bacillariophyceae) genus Adlafia Moser, Lange-Bertalot & Metzeltin from waterbodies of Vietnam https://phytokeys.pensoft.net/article/57657/ PhytoKeys 162: 13-27

DOI: 10.3897/phytokeys.162.57657

Authors: Anton M. Glushchenko, John Patrick Kociolek, Irina V. Kuznetsova, Maxim S. Kulikovskiy

Abstract: Four species of the diatom genus Adlafia were found from waterbodies of Vietnam and described as new to science. Their formal descriptions are presented herein and they are illustrated by light and scanning electron micrographs. These new species are: A. lamdongiensis Glushch., Kulik. & Kociolek, sp. nov., A. babeiensis Glushch., Kulik. & Kociolek, sp. nov., A. vietnamensis Glushch., Kulik. & Kociolek, sp. nov. and A. dauiensis Glushch., Kulik. & Kociolek, sp. nov. These species are then compared to other similar taxa. Our new findings add to the number of species in this interesting genus and contribute to our understanding of the unique diatom flora found in Vietnam.

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Research Article Wed, 7 Oct 2020 10:18:34 +0300
Continental diatom biodiversity discovery and description in China: 1848 through 2019 https://phytokeys.pensoft.net/article/54193/ PhytoKeys 160: 45-97

DOI: 10.3897/phytokeys.160.54193

Authors: J. Patrick Kociolek, Qingmin You, Qi Liu, Yan Liu, Quanxi Wang

Abstract: In this paper we inventory the continental diatom taxa described from inland waters in China, from the first species descriptions dating back to 1848 through 2019. China’s geography and hydrography are complex, including the world’s highest mountains, many large rivers, salty lakes, and large karst regions. From this area, a total of 1128 taxa have been described from China over this time period. We examine the number of taxa described in ca. 20-year intervals and note the periods of time of no to few descriptions, versus time intervals with many taxon descriptions. Early on, taxon descriptions of freshwater diatoms from China were done by mostly by Europeans working alone, and the time frame of 1948 to 1967 had few descriptions, as a devasting famine and the cultural revolution impacted scientific work and productivity. B.V. Skvortzov produced a large number of taxon descriptions, during his time in residence in Harbin, later while in Sao Paulo, Brazil, and even posthumously. More recently, a wide range of labs and collaborations across China, and with a diverse array of international partners, is ushering in a new, robust era of research on the biodiversity of continental diatoms. A few areas of research and work for the future are discussed.

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Review Article Tue, 8 Sep 2020 14:45:10 +0300
Freshwater diatoms in the Democratic Republic of the Congo: a historical overview of the research and publications https://phytokeys.pensoft.net/article/47386/ PhytoKeys 136: 107-125

DOI: 10.3897/phytokeys.136.47386

Authors: Christine Cocquyt, Edit Lokele Ndjombo, Simon Tutu Tsamemba, Hippolyte Nshimba Seya wa Malale

Abstract: An overview of the diatom research in the DR Congo is given based on literature data starting in 1938 with the work of Zanon and excluding the East African Lakes as these were already discussed in previous papers. For each literature record the diatom genera mentioned are presented as well as all diatom taxa described from the Congo as new. In total, 106 new taxa were documented, of which Nitzschia with 40 taxa is far the most important genus followed by Navicula s.l. and Pinnularia and with 15 and 13 taxa respectively. Particular attention was paid to the local research of students found in unpublished theses at bachelor, licentiate, master and PhD level. Diatom records in these works are almost all restricted to genus level, although in the last decade an attempt to delimit species can be observed. This accompanies the renewed taxonomic interest in the Congo basin during the last decade. Renewed taxonomic interest can also be seen in the genera: the first period being situated during the lumping period, while more recent works follow the current taxonomic classification, for example Navicula s.l. versus Navicula, Cavinula, Craticula, Diadesmis, Geissleria, Humidophila, Luticola, etc.

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Checklist Mon, 23 Dec 2019 10:30:26 +0200
The genus Eunotia Ehrenb. (Bacillariophyta) in the Cheremsky Nature Reserve, Ukrainian Polissya, and refined terminology relevant to the raphe system morphology https://phytokeys.pensoft.net/article/35566/ PhytoKeys 128: 1-31

DOI: 10.3897/phytokeys.128.35566

Authors: Lyudmila N. Bukhtiyarova

Abstract: Numerous species of Eunotia Ehrenb., widely distributed in the world flora, prefer acidic, dystrophic or oligotrophic freshwater habitats with low conductivity and usually occur in epiphytic or epilithic hydrotopes. In Ukraine, only 32 species and eight varieties of Eunotia were known until this study. For the first time, 9 more species have been recorded mainly from the Cheremsky Nature Reserve, located in Ukrainian Polissya. New findings include 2 species widely distributed in the world flora on most continents and 7 rare species known from several locations, among them E. genuflexa, E. jarensis and E. ruzickae, which are probably European endemics as they have not been reported from other continents. For the present time in the Cheremsky Nature Reserve, the 20 species recorded here, the highest species richness of Eunotia in Ukraine, bring the total number of Eunotia in Ukraine to 41 species, which comprises only 7% of Eunotia species in the world flora. This is indirect evidence of insufficient investigation of the wetlands in Ukraine where Eunotia usually is represented with high species richness. Several definitions are suggested to describe morphological features that are peculiar to the diatom frustule particular to the Eunotia species. The genus Eunotia possesses a mirror-symmetric, mantle-offset, brevisslit raphe system, which may or may not have terminal raphe fissures. Morphological analysis provided in this study revealed the absence of terminal raphe fissures for many species of Eunotia. Instead, the distal ends of the raphe slits finish on the outer valve surface by funnel holes, sometimes pore-like ones, connected with the helictoglossae. However, in the literature those distal ends of the raphe slits were described erroneously as terminal raphe fissures. For the first time different types of raphe system are grounded. Two species Eunotia implicata Nörpel-Schempp et al. in Alles et al. and Eunotia incisa W. Smith ex Gregory were lectotypified.

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Research Article Tue, 23 Jul 2019 13:33:38 +0300
Diatoms from Wrangell-St. Elias National Park, Alaska, USA https://phytokeys.pensoft.net/article/29456/ PhytoKeys 113: 33-57

DOI: 10.3897/phytokeys.113.29456

Authors: Loren Bahls, Tara Luna

Abstract: As a contribution to our knowledge of diatom biodiversity and biogeography in the United States, high resolution light microscope images are provided for 139 diatom taxa recorded from lake, stream, spring and glacier habitats in Wrangell-St. Elias National Park, Alaska. The spring had the highest taxa richness of the four habitats that were sampled, likely owing to the relative stability of this habitat compared to the others. Most of the taxa were described from northern and alpine locations in Europe and North America and are typical of habitats in the northern Rocky Mountains, with two notable exceptions. Surirella arctica had been reported previously only from locations in the High Arctic of North America, north of 68°N latitude. Gomphonema caperatum has a disjunct distribution in montane regions of the eastern and far western contiguous United States. This may be the first record of this taxon from Alaska.

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Research Article Thu, 6 Dec 2018 14:16:51 +0200
Evidence from checklists for a Holarctic (circumboreal) kingdom of diatoms https://phytokeys.pensoft.net/article/26277/ PhytoKeys 108: 13-24

DOI: 10.3897/phytokeys.108.26277

Authors: Loren Bahls

Abstract: Published checklists of freshwater diatoms that represent the American Northwest, Laurentian Great Lakes, Germany and the South Polar Region were compared systematically and the numbers of taxa shared by two or more of these regions were noted. There is a higher level of floristic correspondence between the American Northwest and Germany (71%) and between the American Northwest and the Laurentian Great Lakes (64%) than between the American Northwest and the South Polar Region (45%). These findings support a Holarctic Kingdom of diatoms that is parallel to the Holarctic Kingdom of flowering plants. Mountains and coastal areas and/or inland waters of high salinity may explain why the American Northwest and Germany have more taxa in common than the American Northwest and the Laurentian Great Lakes. Common riverine diatom taxa in the American Northwest are similar to those reported from nationwide monitoring stations. The number of truly cosmopolitan species – those found on all continents – is probably less than 300. The terms “cosmopolitan”, “endemic” and “native” are often misused when applied to diatoms and the first two terms always need to be qualified.

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Research Article Mon, 13 Aug 2018 11:36:55 +0300
Differentiating Iconella from Surirella (Bacillariophyceae): typifying four Ehrenberg names and a preliminary checklist of the African taxa https://phytokeys.pensoft.net/article/13542/ PhytoKeys 82: 73-112

DOI: 10.3897/phytokeys.82.13542

Authors: Regine Jahn, Wolf-Henning Kusber, Christine Cocquyt

Abstract: To comply with the new phylogeny within the Surirellales as supported by molecular and morphological data, re-evaluations and re-combinations of taxa from and within the genera Surirella, Cymatopleura, and Stenopterobia and with the re-established genus Iconella are necessary. Since the African diatom flora is rich with taxa from these genera, especially Iconella, and the authors have studied these taxa recently, describing also new taxa, a preliminary checklist of African Iconella and Surirella is here presented. 94 names are contained on this list. 57 taxa have been transferred to Iconella; 55 taxa were formerly ranked within Surirella and two taxa within Stenopterobia. 10 taxa have stayed within Surirella and six taxa have been transferred from Cymatopleura to Surirella. 20 Surirella and 1 Stenopterobia names are listed which are either unrevised or unrevisable since morphological data is missing. Four names and taxa described by Ehrenberg are here typified. Two had been transferred to Iconella already: Iconella bifrons (Ehrenb.) Ruck & Nakov and Iconella splendida (Ehrenb.) Ruck & Nakov. Two are re-transferred from Cymatopleura to Surirella: Surirella librile (Ehrenb.) Ehrenb. and Surirella undulata (Ehrenb.) Ehrenb.; both taxa are currently known by their younger synonyms: Cymatopleura solea (Bréb.) W. Smith and Cymatopleura elliptica (Bréb. ex Kützing) W. Smith. Lectotypes for Iconella bifrons, I. splendida, Surirella librile, and S. undulata were designated.

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Research Article Mon, 3 Jul 2017 09:21:11 +0300
Typification and taxonomic status re-evaluation of 15 taxon names within the species complex Cymbella affinis/tumidula/turgidula (Cymbellaceae, Bacillariophyta) https://phytokeys.pensoft.net/article/4782/ PhytoKeys 53: 1-25

DOI: 10.3897/phytokeys.53.4782

Authors: Weliton José da Silva, Regine Jahn, Thelma Alvim Veiga Ludwig, Friedel Hinz, Mariângela Menezes

Abstract: Specimens belonging to the C. affinis / C. tumidula / C. turgidula species complex have many taxonomic problems, due to their high morphological variability and lack of type designations. Fifteen taxon names of this complex, distributed in five species, were re-evaluated concerning their taxonomic status, and lectotypified based on original material. In addition to light microscopy, some material was analyzed by electron microscopy. Four new combinations are proposed in order to reposition infraspecific taxa.

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Research Article Tue, 21 Jul 2015 00:25:45 +0300
Diatoms from Brazil: the taxa recorded by Christian Gottfried Ehrenberg https://phytokeys.pensoft.net/article/1446/ PhytoKeys 18: 19-37

DOI: 10.3897/phytokeys.18.3653

Authors: Weliton da Silva, Regine Jahn, Mariângela Menezes

Abstract: The flora of diatoms from Brazil has been studied by several authors from the beginning of the 19th up to now. Some of the old lists and descriptions are unknown or have been ignored by Brazilian researchers and the situation of the names cited was not assessed. Here we compiled a list of 101 taxa of diatoms from Brazil registered by Christian Gottfried Ehrenberg during the 19th century. We checked the current nomenclatural status of those taxa and lectotypified species from Brazil described by this author. For this, we accessed the Ehrenberg collection in the Museum für Naturkunde, Berlin, Germany, where 11 samples from Brazil studied by Ehrenberg are housed and published in different papers. Using these samples, we found 101 taxa (specific and infraspecific) published by Ehrenberg from Brazil. Five species (Eunotia bidens Ehrenb., E. depressa Ehrenb., E. elephas Ehrenb., Pinnularia microstauron Ehrenb., and Terpsinoe brasiliensis Ehrenb.) were new descriptions and were lectotypified here. The other species cited for Brazil were described initially from other places. However, 23 names were invalid and one illegitimate.

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Catalogue Mon, 19 Nov 2012 00:00:00 +0200