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Karen S. Renzaglia - One of the best experts on this subject based on the ideXlab platform.
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Structure and development of Nostoc strands in Leiosporoceros dussii (Anthocerotophyta): a novel symbiosis in land plants
American Journal of Botany, 2006Co-Authors: A Juan Carlos Villarreal, Karen S. RenzagliaAbstract:The presence of Nostoc in longitudinally oriented schizogenous canals is a feature that separates Leiosporoceros from all other hornworts and represents a novel symbiotic arrangement in land plants. In surface view, Nostoc canals are visible as elongated, dichotomously branched blue-green strands. All other hornworts develop numerous discrete globose colonies through continuous production of mucilage clefts as avenues for multiple invasions within a single thallus. To elucidate the anatomy and development of the unusual Nostoc strands in Leiosporoceros, we examined sporeling development in culture and the structure of strands in field-collected plants using light and electron microscopy. Rosette-like sporelings have mucilage clefts scattered along swollen apices. All field specimens were strap-shaped, contained Nostoc, and lacked mucilage clefts. Nostoc strands are located in the center of the thallus and develop behind the apical cell by separation of the middle lamella between apical derivatives. Strands elongate and branch in synchrony with apical growth, and thus only a single invasion is required for strand production. Two distinct ultrastructural morphotypes in the collections suggest nonspecificity of Nostoc. We speculate that Nostoc enters the thallus in the sporeling stage through mucilage clefts, and once colonies are established, cleft production ceases.
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LEIOSPOROCEROS DUSSII (Anthocerotophyta): A NOVEL SYMBIOSIS IN LAND PLANTS 1
2006Co-Authors: A Juan Carlos Villarreal, Karen S. RenzagliaAbstract:The presence of Nostoc in longitudinally oriented schizogenous canals is a feature that separates Leiosporoceros from all other hornworts and represents a novel symbiotic arrangement in land plants. In surface view, Nostoc canals are visible as elongated, dichotomously branched blue-green strands. All other hornworts develop numerous discrete globose colonies through continuous production of mucilage clefts as avenues for multiple invasions within a single thallus. To elucidate the anatomy and development of the unusual Nostoc strands in Leiosporoceros, we examined sporeling development in culture and the structure of strands in field-collected plants using light and electron microscopy. Rosette-like sporelings have mucilage clefts scattered along swollen apices. All field specimens were strap-shaped, contained Nostoc, and lacked mucilage clefts. Nostoc strands are located in the center of the thallus and develop behind the apical cell by separation of the middle lamella between apical derivatives. Strands elongate and branch in synchrony with apical growth, and thus only a single invasion is required for strand production. Two distinct ultrastructural morphotypes in the collections suggest nonspecificity of Nostoc. We speculate that Nostoc enters the thallus in the sporeling stage through mucilage clefts, and once colonies are established, cleft production ceases.
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the sporophyte gametophyte junction in the hornwort dendroceros tubercularis hatt Anthocerotophyta
New Phytologist, 1990Co-Authors: R. Ligrone, Karen S. RenzagliaAbstract:SUMMARY The placenta of the anthocerote, Dendroceros tubercularis Hatt., consists of long and branched haustorial cells, that arise from the foot and gametophyte transfer cells. Both cell types contain electron-dense vacuolar deposits that were digested by pronase and therefore are assumed to be protein. These deposits were negative to the PATAg test for carbohydrates. Protein bodies were also found in the parenchyma cells of the foot and younger meristematic cells at the base of the capsule. Vacuolar deposits of osmiophilic material in the gametophyte cells external to the placenta were stained non-specifically with PATAg method and were not affected by pronase. The haustorial cells have pleomorphic plastids lacking starch and a thylakoid system, whereas the transfer cells have well developed chloroplasts. No pronase-sensitive material was detected in the apoplastic space separating gametophyte and sporophyte cells. These results suggest that protein is synthesized in the haustorial cells, perhaps from precursors provided by transfer cells, and is then transferred, via plasmodesmata, to the parenchyma cells of the foot and eventually to the cells of the growing capsule.
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The sporophyte–gametophyte junction in the hornwort, Dendroceros tubercularis Hatt (Anthocerotophyta)
New Phytologist, 1990Co-Authors: R. Ligrone, Karen S. RenzagliaAbstract:SUMMARY The placenta of the anthocerote, Dendroceros tubercularis Hatt., consists of long and branched haustorial cells, that arise from the foot and gametophyte transfer cells. Both cell types contain electron-dense vacuolar deposits that were digested by pronase and therefore are assumed to be protein. These deposits were negative to the PATAg test for carbohydrates. Protein bodies were also found in the parenchyma cells of the foot and younger meristematic cells at the base of the capsule. Vacuolar deposits of osmiophilic material in the gametophyte cells external to the placenta were stained non-specifically with PATAg method and were not affected by pronase. The haustorial cells have pleomorphic plastids lacking starch and a thylakoid system, whereas the transfer cells have well developed chloroplasts. No pronase-sensitive material was detected in the apoplastic space separating gametophyte and sporophyte cells. These results suggest that protein is synthesized in the haustorial cells, perhaps from precursors provided by transfer cells, and is then transferred, via plasmodesmata, to the parenchyma cells of the foot and eventually to the cells of the growing capsule.
R. Ligrone - One of the best experts on this subject based on the ideXlab platform.
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the sporophyte gametophyte junction in the hornwort dendroceros tubercularis hatt Anthocerotophyta
New Phytologist, 1990Co-Authors: R. Ligrone, Karen S. RenzagliaAbstract:SUMMARY The placenta of the anthocerote, Dendroceros tubercularis Hatt., consists of long and branched haustorial cells, that arise from the foot and gametophyte transfer cells. Both cell types contain electron-dense vacuolar deposits that were digested by pronase and therefore are assumed to be protein. These deposits were negative to the PATAg test for carbohydrates. Protein bodies were also found in the parenchyma cells of the foot and younger meristematic cells at the base of the capsule. Vacuolar deposits of osmiophilic material in the gametophyte cells external to the placenta were stained non-specifically with PATAg method and were not affected by pronase. The haustorial cells have pleomorphic plastids lacking starch and a thylakoid system, whereas the transfer cells have well developed chloroplasts. No pronase-sensitive material was detected in the apoplastic space separating gametophyte and sporophyte cells. These results suggest that protein is synthesized in the haustorial cells, perhaps from precursors provided by transfer cells, and is then transferred, via plasmodesmata, to the parenchyma cells of the foot and eventually to the cells of the growing capsule.
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The sporophyte–gametophyte junction in the hornwort, Dendroceros tubercularis Hatt (Anthocerotophyta)
New Phytologist, 1990Co-Authors: R. Ligrone, Karen S. RenzagliaAbstract:SUMMARY The placenta of the anthocerote, Dendroceros tubercularis Hatt., consists of long and branched haustorial cells, that arise from the foot and gametophyte transfer cells. Both cell types contain electron-dense vacuolar deposits that were digested by pronase and therefore are assumed to be protein. These deposits were negative to the PATAg test for carbohydrates. Protein bodies were also found in the parenchyma cells of the foot and younger meristematic cells at the base of the capsule. Vacuolar deposits of osmiophilic material in the gametophyte cells external to the placenta were stained non-specifically with PATAg method and were not affected by pronase. The haustorial cells have pleomorphic plastids lacking starch and a thylakoid system, whereas the transfer cells have well developed chloroplasts. No pronase-sensitive material was detected in the apoplastic space separating gametophyte and sporophyte cells. These results suggest that protein is synthesized in the haustorial cells, perhaps from precursors provided by transfer cells, and is then transferred, via plasmodesmata, to the parenchyma cells of the foot and eventually to the cells of the growing capsule.
Christine Cargill - One of the best experts on this subject based on the ideXlab platform.
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Notes on Early Land Plants Today. 70. Nomenclatural notes in hornworts (Anthocerotophyta)
Phytotaxa, 2015Co-Authors: Juan Carlos Villarreal, Christine Cargill, Lars Söderström, Anders Hagborg, Matt Von KonratAbstract:Prior to the publication of the world checklist of hornworts and liverworts (Soderstrom et al ., in press) some taxa still need to be validated, transferred or synonymized. We are here dealing with the remaining nomenclatural issues among the Anthocerotophyta. Several taxa have not been typified properly and we are here suggesting several new lectotypes to stabilize the nomenclature.
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nuevos registros de antocerotes Anthocerotophyta rothm ex stotler crand stotler en cuba
Ciencia en su PC, 2011Co-Authors: Yoira Riveraqueralta, Christine CargillAbstract:Resumen es: Los antocerotes (Anthocerotophyta) son un grupo poco estudiado en Cuba, si se compara con el nivel de conocimiento que se tiene de los musgos y las hepat...
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nuevos registros de antocerotes Anthocerotophyta rothm
2011Co-Authors: Yoira Riveraqueralta, Christine Cargill, Ex Stotler, Investigaciones BotanicasAbstract:The hornworts (Anthocerotophyta) are poorly studied in Cuba, compared to mosses and liverworts (Bryophyta and Marchantophyta). This study is based on the revision of herbarium material; literature consultation and the use of the optic and electronic microscopy of Scanning (JEOL LSM 6400 SEMs). After this study, the species: Anthoceros hispidus Steph. (Anthocerotaceae) and Phaeoceros oreganos (Aust.) Steph. (Notothyladaceae) were recognized and recorded for the first time in Cuba. Also, this study offered a characterization of them, photos and
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nuevos registros de antocerotes Anthocerotophyta rothm ex stotler crand stotler en cuba new records of hornworts Anthocerotophyta rothman
2011Co-Authors: Christine CargillAbstract:The hornworts (Anthocerotophyta) are poorly studied in Cuba, compared to mosses and liverworts (Bryophyta and Marchantophyta). This study is based on the revision of herbarium material; literature consultation and the use of the optic and electronic microscopy of Scanning (JEOL LSM 6400 SEMs). After this study, the species: Anthoceros hispidus Steph. (Anthocerotaceae) and Phaeoceros oreganos (Aust.) Steph. (Notothyladaceae) were recognized and recorded for the first time in Cuba. Also, this study offered a characterization of them, photos and
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nuevos registros de antocerotes Anthocerotophyta rothm ex stotler crand stotler en cuba new records of hornworts Anthocerotophyta rothman stotlar crand ex stotlar in cuba
Ciencia en su PC, 2011Co-Authors: Yoira Riveraqueralta, Christine CargillAbstract:Los antocerotes (Anthocerotophyta) son un grupo poco estudiado en Cuba, si se compara con el nivel de conocimiento que se tiene de los musgos y las hepaticas (Bryophyta y Marchantophyta). En el presente estudio, a partir de la revision de material de herbario, la consulta de literatura especializada y el empleo de la microscopia optica y electronica de barrido (JEOL LSM 6400 SEMs) se registran y se reconocen por primera vez en Cuba las especies Anthoceros hispidus Steph. (Anthocerotaceae) y Phaeoceros oreganus (Aust.) Steph. (Notothyladaceae); ademas, se ofrece su caracterizacion, fotos y fotomicrografias de las esporas. Se mapifica su distribucion y se ofrecen datos sobre la autecologia de las especies, asi como propuestas para la conservacion de las especies estudiadas. ABSTRACT The hornworts (Anthocerotophyta) are poorly studied in Cuba, compared to mosses and liverworts (Bryophyta and Marchantophyta). This study is based on the revision of herbarium material; literature consultation and the use of the optic and electronic microscopy of Scanning (JEOL LSM 6400 SEMs). After this study, the species: Anthoceros hispidus Steph. (Anthocerotaceae) and Phaeoceros oreganos (Aust.) Steph. (Notothyladaceae) were recognized and recorded for the first time in Cuba. Also, this study offered a characterization of them, photos and spores photomicrographs. Distribution maps are shown and the data on autecology species are offered; as well as proposals for the conservation of the species studied.
Sahut Chantanaorrapint - One of the best experts on this subject based on the ideXlab platform.
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Taxonomic Studies on Thai Anthocerotophyta II. The Genus Notothylas (Notothyladaceae)
Cryptogamie Bryologie, 2015Co-Authors: Sahut ChantanaorrapintAbstract:Abstract The genus Notothylas Sull. in Thailand is reviewed, based on herbarium specimens and field surveys. Eight species of the genus are recognized and two of them, N. pandei Udar et V. Chandra and N. yunannensis T. Peng et R.L. Zhu, are newly recorded in the country. The new species Notothylas frahmii Chantanaorr. is described and illustrated. A key to species, brief descriptions and selected illustrations for the species of Notothylas of Thailand are provided.
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taxonomic studies on thai Anthocerotophyta i the genera dendroceros and megaceros dendrocerotaceae
TAIWANIA, 2014Co-Authors: Sahut ChantanaorrapintAbstract:A taxonomic review of the hornwort genera ＂Dendroceros＂ Nees and ＂Megaceros＂ Campb. in Thailand is presented, based on herbarium specimens and field surveys. Three species are recognized, namely ＂D. cucullatus＂ Steph., ＂D. suplanus＂ Steph. and ＂M. flagellaris＂ (Mitt.) Steph. A key, descriptions and line drawings and notes on the ecology and geographical distribution of the species are provided.
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Reappraisal of Dendroceros cucullatus (Dendrocerotaceae, Anthocerotophyta)
Phytotaxa, 2014Co-Authors: Sahut Chantanaorrapint, Tao Peng, Rui-liang ZhuAbstract:Dendroceros is an epiphytic or epiphyllous genus within Anthocerotophyta, with about 48 extremely specialised species in having endosporic germination (Villarreal et al. 2010 ; Garcia et al. 2012). Dendroceros difficilis was originally described by Stephani (1917: 1009), based on a collection made by V. Schiffner from Java, Indonesia. Hasegawa (1980) reduced a little-known species D. cucullatus Stephani (1923: 429) from the Philippines, to its synonym. An examination of the holotypes of both species, however, reveals that D. cucullatus is quite different from D. difficilis in thallus margin, structure of costa and epidermal cells of capsule. Dendroceros cucullatus is thus reinstated as a separate species. Based on Schuster’s (1987) treatment, these two species belong to subgenus Apoceros Schuster (1987: 195) based on the cavernous costa in both. Dendroceros difficilis has been described and illustrated by Hasegawa (1980) and Piippo (1993). The following description of D. cucullatus is based on the holotype kept in Geneva Herbarium (G) and recently collections from Thailand.
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NOTOTHYLAS IRREGULARIS (NOTOTHYLADACEAE, Anthocerotophyta), A NEW SPECIES OF HORNWORT FROM NORTHERN THAILAND
Acta Botanica Hungarica, 2014Co-Authors: Sahut ChantanaorrapintAbstract:Notothylas irregularis Chantanaorr. is described and illustrated from Doi Chiang Dao Wildlife Sanctuary, Chiang Dao District, Chiang Mai Province, northern Thailand. It is similar to Notothylas yunnanensis T. Peng et R. L. Zhu, but differs in its capsules with a line of incrassate cells.
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Liverworts and hornworts of Thailand: an updated checklist and bryofloristic accounts
Annales Botanici Fennici, 2008Co-Authors: Ming-jou Lai, Rui-liang Zhu, Sahut ChantanaorrapintAbstract:An updated checklist of liverworts (Marchantiophyta) and hornworts (Anthocerotophyta) of Thailand is presented. The checklist is based on published literature and some recent collections. The liverwort and hornwort flora of Thailand consists of 386 species belonging to 90 genera in 37 families. The largest family is Lejeuneaceae (123 spp., 25 genera). The genera with over ten species are Cololejeunea (38 spp.), Plagiochila (37 spp.), Frullania (37 spp.), Bazzania (34 spp.), and Radula (21 spp.). Sixteen species are known only from Thailand, but no genera are endemic to the country. A new name (Cololejeunea gradsteinii M.J. Lai & R.L. Zhu, nom. nov.) and a new combination (Heteroscyphus inflatus (Steph.) S.C. Srivast. & A. Srivast. var. fragilissimus (N. Kitag.) M.J. Lai & R.L. Zhu, comb, nova) are proposed. Eleven species are reported for Thailand for the first time. Vegetation and bryofloristic accounts of Thailand are also discussed.
Raymond E. Stotler - One of the best experts on this subject based on the ideXlab platform.
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On Anthoceros phymatodes M. Howe and the hornwort genus Phymatoceros stotler, W. T. Doyle & crand.-stotl. (Anthocerotophyta)
Cryptogamie Bryologie, 2006Co-Authors: Barbara Crandall-stotler, Raymond E. Stotler, William T. DoyleAbstract:Based upon our study of type specimens, we confirm that Anthoceros phymatodes M. Howe from California is synonymous with Phaeoceros bulbiculosus (Brot.) Prosk. from Portugal. Furthermore, this taxon forms the basis for the recently named, monotypic genus Phymatoceros Stotler, W. T. Doyle & Crand.-Stotl. Our observations of the morphology, anatomy, and phenology of living populations from both California and Portugal reveal a suite of characters that discriminate this taxon, not only from Phaeoceros Prosk., but also from all other hornwort genera. These include rounded to spindle-shaped chloroplasts with abundant, bulging starch grains that may obscure a pyrenoid; highly dimorphic, dioicous thalli; a single antheridium per antheridial chamber, rather than 2 to 4 as in Phaeoceros; and spores that are fuscous at maturity.
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on anthoceros phymatodes m howe and the hornwort genus phymatoceros stotler w t doyle crand stotl Anthocerotophyta
Cryptogamie Bryologie, 2006Co-Authors: Barbara Crandallstotler, Raymond E. Stotler, William T. DoyleAbstract:Based upon our study of type specimens, we confirm that Anthoceros phymatodes M. Howe from California is synonymous with Phaeoceros bulbiculosus (Brot.) Prosk. from Portugal. Furthermore, this taxon forms the basis for the recently named, monotypic genus Phymatoceros Stotler, W. T. Doyle & Crand.-Stotl. Our observations of the morphology, anatomy, and phenology of living populations from both California and Portugal reveal a suite of characters that discriminate this taxon, not only from Phaeoceros Prosk., but also from all other hornwort genera. These include rounded to spindle-shaped chloroplasts with abundant, bulging starch grains that may obscure a pyrenoid; highly dimorphic, dioicous thalli; a single antheridium per antheridial chamber, rather than 2 to 4 as in Phaeoceros; and spores that are fuscous at maturity.
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A Revised Classification of the Anthocerotophyta and a Checklist of the Hornworts of North America, North of Mexico
The Bryologist, 2005Co-Authors: Raymond E. Stotler, Barbara Crandall-stotlerAbstract:A hornwort classification that recognizes 11 genera, comprising a hierarchy of two classes, three orders, and four families is proposed. The updated checklist of these bryophytes for North America has been expanded from 11 species in three genera to 17 species in five genera. Application of the genus name Anthoceros in the traditional sense is clarified.
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1596 1597 proposals to conserve the name anthoceros with a conserved type and the name anthoceros agrestis against a nagasakiensis Anthocerotophyta
Taxon, 2003Co-Authors: Raymond E. Stotler, Barbara CrandallstotlerAbstract:When Linnaeus (Sp. PI.: 1139. 1753) named the genus Anthoceros he included three species, namely, A. punctatus, A. laevis, and A. multifidus. Anthoceros multifidus was later removed from the genus and transferred to Riccardia by Gray (Nat. Arr. Brit. PI.: 684. 1821 'Riccardius') leaving two of the original species in the genus Anthoceros. Anthoceros punctatus was selected as the generitype by Proskauer (Ann. Bot., n.s. 12: 259. 1948). His selection remained uncontested until Schuster (J. Hattori Bot. Lab. 26: 299. 1963) suggested that Proskauer should have selected A. laevis as the type rather than A. punctatus. That is because Proskauer later decided (Bull. Torrey Bot. Club 78: 346, 1951) that these two original species of Anthoceros actually represented two different genera. Since he had selected A. punctatus as the type, it had to remain with Anthoceros, so he transferred A. laevis to his new genus Phaeoceros (Proskauer I.c., 1951). Anthoceros punctatus had long been considered to be conspecific with Aspiromitus husnotii Steph., the generitype of Aspiromitus Steph. (Proskauer, I.c., 1948: 262), and Schuster (I.c., 1963) stated that "Aspiromitus, typified by A. husnotii (= A. punctatus) must be used for one of the two elements originally included in Anthoceros by Linnaeus, and Anthoceros must be retained for the other ('law of residues')". Following his logic, the two species of Linnaeus would then be Anthoceros laevis and Aspiromitus punctatus; he did not, however, make any new combinations in 1963. Schljakov (Novosti Sist. Niz. Rast. 13: 225. 1976) agreed with Schuster (I.c., 1963) and implicitly lectotypified Anthoceros with Anthoceros laevis, making the new combination Aspiromitus punctatus (L.) Schljak. Grolle (Acta Bot. Fenn. 121: 5. 1983) pointed out that such a later lectotypification was contrary to the provisions of the ICBN, particularly with the removal of any appeal to the "law of residues" in the edition adopted at the Sydney Congress of 1981 (Voss & al., Regnum Veg. 111. 1983) and had to be rejected. That would have been the case except for the provision of the ICBN, first adopted at the Seattle Congress in 1969 (cf. Art. 8 (last clause) in Stafleu & al., Regnum Veg. 82. 1972), and now expressed as Article 10.5(b) of the ICBN (Greuter & al., Regnum Veg. 138. 2000) that a choice of lectotype for the name of a genus or subdivision of a genus may be superseded if ". . . it was based on a largely mechanical method of selection". The selection by Proskauer (l.c., 1948: 262) was obviously mechanical since he wrote: "Anthoceros punctatus was described by Linne (1753) as the first species of Anthoceros. It is here, therefore, considered as the type of the genus". Although the actions of Schuster (l.c., 1963) and Schljakov (l.c.) do not represent formal designation of a type as required by Art. 7.11 of the ICBN, more recently Schuster (Hepaticae and Anthocerotae of North America 6: 745. 1992), following his description of Anthoceros, wrote: "Type. Anthoceros laevis L. The reasons for the present type designation are discussed at length, below". Although this later designation was based solely upon the "law of residues" with no mention whatsoever of the mechanical choice by Proskauer (l.c. 1948: 262), Art. 10 Ex. 7, a "voted example", makes clear that any later type designation that meets the requirements of Art. 7.11 supersedes a choice "based on a largely mechanical method of selections". Therefore, unless the Proskauer designation of A. punctatus is conserved as the type of the name Anthoceros, it must be considered to have been superseded by Schuster's (I.c. 1992: 745) choice of A. laevis. With A. laevis as the generitype, the species of Phaeoceros must either be returned to or transferred to Anthoceros and all species now considered to be members of Anthoceros must be transferred to Aspiromitus. Schuster (l.c., 1992) and Schljakov (l.c.) have already begun this lengthy task to a very limited extent. Not only will the number of new combinations be high, including well over 100 of the 293 binomials listed by Bonner (in Index Hepat. 2. 1962) under Anthoceros, the confusion this will cause will be unprecedented. This will likewise result in changing the generic name for 131 sequences
