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Eric H Roalson - One of the best experts on this subject based on the ideXlab platform.
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Eleocharis endounifascis a new species of Eleocharis subgenus limnochloa cyperaceae from northern south america
Phytotaxa, 2013Co-Authors: Cody E. Hinchliff, Stephanie Petersen, Eric H RoalsonAbstract:A new species, Eleocharis endounifascis, is described and illustrated. This species inhabits standing water in disturbed, open habitats, occurring among a mosaic of wet forest, and probably also flourishes in sunny, seasonally inundated wetlands from Belize to southeastern Venezuela and Guyana to Brazil. It was previously confused with Eleocharis interstincta in herbarium collections and floristic works.
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phylogenetic relationships in Eleocharis cyperaceae c4 photosynthesis origins and patterns of diversification in the spikerushes
Systematic Botany, 2010Co-Authors: Eric H Roalson, Cody E. Hinchliff, Rafael Trevisan, Carlos Roberto Maximiano Da SilvaAbstract:Abstract Eleocharis (Cyperaceae) is a morphologically and physiologically diverse lineage of 250 + species with a cosmopolitan distribution. We here explore phylogenetic relationships in this lineage using maximum parsimony and Bayesian inference analyses of nrDNA ITS and cpDNA tmC-ycf6 and ycf6-psbM sequence data with the goals of comparing our phylogenetic hypotheses to previous classifications, morphological variation, and photosynthetic pathway variation. Our results suggest that in Eleocharis C4 photosynthesis has been derived at least three times, with several cases of possible reversion to C3-like or intermediate pathways and several additional origins of C3–C4 intermediate photosynthetic pathways, as inferred by carbon isotope ratio measurements. Many classification units currently recognized in Eleocharis are not monophyletic, however, E. subgenus Limnochloa and E. subgenus Scirpidium are monophyletic. Other classification units largely corresponding to clades include E. subgenus Zinserlingia, E....
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The origins of Eleocharis (Cyperaceae) and the status of Websteria, Egleria, and Chillania
TAXON, 2010Co-Authors: Cody E. Hinchliff, Ariel Lliully, Timothy Carey, Eric H RoalsonAbstract:Eleocharis R. Br. is an ecologically and economically important genus that contains about 250 species of annual and perennial sedges, with centers of diversity in seasonally wet tropical to subtropical regions. Phylogenetic relationships in the genus are poorly understood, particularly in relation to three monotypic genera—Egleria L.T. Eiten, Chillania Roivainen, and Websteria (Poir.) S. Hooper—which have been variously included or excluded from Eleocharis in different classifications. These genera, while morphologically distinct, show characteristics that fall within the range of variation seen in Eleocharis. The relationship between the clade containing Eleocharis and these segregate genera (i.e., Eleocharideae) and the rest of Cyperaceae has also been difficult to determine from previous studies, and numerous conflicting hypotheses have been suggested. To address these uncertainties, we sequenced cpDNA from the ndhF and psbB-psbH marker regions and used it to reconstruct the phylogenetic history of Eleocharis and a broad sample of other Cyperaceae. We found that Egleria and Websteria are derived from within Eleocharis, and that this clade, representing the Eleocharideae, is sister to the Abildgaardieae. Chillania could not be included in the molecular dataset, but its morphology suggests it should be included in Eleocharis. New nomenclature is suggested to place the species of Chillania, Egleria, and Websteria in Eleocharis. Our phylogenetic reconstructions also indicate several other instances of generic paraphyly in other Cyperaceae lineages.
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stem architecture in Eleocharis subgenus limnochloa cyperaceae evidence of dynamic morphological evolution in a group of pantropical sedges
American Journal of Botany, 2009Co-Authors: Cody E. Hinchliff, Eric H RoalsonAbstract:We examined phylogenetic relationships and patterns of stem structural evolution in Eleocharis subgenus Limnochloa , an ecologically and economically important group of tropical to temperate-growing sedges, whose stems serve as the primary photosynthetic organs. We used maximum parsimony, likelihood, and Bayesian inference to develop phylogenetic trees and stochastic mapping and a Markov one-rate model to develop character history reconstructions of stem architecture. A complex history of stem shape evolution characterized by a high degree of homoplasy and rapid rates of change (an average of 13 transitions per character history for about 25 species) was identifi ed across subgenus Limnochloa . Character states transition much more frequently in some lineages than others, but tend to follow a consistent directional pattern of evolutionary change. Our data also suggest that changes in stem shape and anatomy may be associated with speciation events in the subgenus (Pagel ’ s κ = 0.3503, P = 0.04579) and may have some adaptive signifi cance. The potential adaptive roles of stem structural traits are unclear, but may be elucidated by further studies. This work serves as a starting point for future evolutionary studies of stem shape and structure in monocots and provides important background knowledge for further studies of ecological adaptations of Eleocharis .
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diversity and plasticity of c4 photosynthesis in Eleocharis cyperaceae
Functional Plant Biology, 2007Co-Authors: Lesley R Murphy, Eric H Roalson, Joao Barroca, Vincent R Franceschi, Raymond W Lee, Gerald E EdwardsAbstract:Eleocharis contains many amphibious species, and displays diversity of photosynthetic mechanism (C3, C4 or C3-C4 intermediates). A unique feature of Eleocharis is the plasticity in the photosynthetic mechanism of some species in response to the environment. In this study, we have examined the culm anatomy and photosynthetic property of several Eleocharis species grown terrestrially and the changes in the newly produced culms over a short period time frame after switching from terrestrial to submerged condition. Eleocharis baldwinii (Torrey) Chapman is C4-like in terrestrial habitat, exhibiting O2 inhibition of photosynthesis with Rubisco expressed in both mesophyll and bundle sheath cells and PEPC strictly in the mesophyll cells, but switches to C3-C4 intermediacy when submerged. In addition to Eleocharis vivipara Link type 1 (which switches from C4-like to C3), two other photosynthetic types examined in this study were shown to have different responses to growth in either terrestrial or submerged conditions. E. vivipara type 2 is a typical C4 plant in the terrestrial habitat, but becomes a C3-C4 intermediate under submerged conditions. Further, terrestrially, E. vivipara type 3 is a C3-C4 intermediate, but when submerged the δ13C value increases to -6.7‰, indicating its use of bicarbonate as a major carbon source. The submerged form of this plant exhibited about three times higher photosynthetic O2 evolution rate, compared to the C3 species Eleocharis erythropoda Steudel. These Eleocharis species possess different molecular switches for regulating C4 gene expression in response to environmental stimuli both between different species, and in E. vivipara among different populations. The apparent expression of a bicarbonate transport system by E. vivipara type 3 while submerged represents a unique adaptation to low CO2 availability.
Jan Kosnar - One of the best experts on this subject based on the ideXlab platform.
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natural hybridization in tropical spikerushes of Eleocharis subgenus limnochloa cyperaceae evidence from morphology and dna markers
American Journal of Botany, 2010Co-Authors: Eliska Rejmankova, Jan Kosnar, Miroslava Herbstova, Petr Macek, Milan StechAbstract:PREMISE OF THE STUDY: Natural hybridization represents an important force driving plant evolution and affecting community structure and functioning. Hybridization may be overlooked, however, among morphologically highly uniform congeners. An excellent example of such a group is Eleocharis subgenus Limnochloa, which has no reliably proven hybrids. Does this reflect biological barriers to interspecific crosses or difficulties in detecting the hybrids? We tested the hypothesis that hybridization occurs among sympatric Eleocharis cellulosa, E. interstincta, and E. mutata in northern Belize, Central America. • METHODS: Morphometric study (407 plants) was followed by examination of inter-simple sequence repeat (ISSR) polymorphisms (44 plants) and ITS sequence variation (33 plants). • KEY RESULTS: Two putatively hybrid morphotypes were discerned-E. cellulosa-resembling and E. interstincta-resembling. DNA markers of E. cellulosa and E. interstincta displayed additive constitution in plants from one E. cellulosa-resembling population only. The other putatively hybrid populations contained ISSR and ITS markers of the species they resembled morphologically, several unique ISSR markers, and ITS sequences of an undescribed South American Limnochloa entity. DNA markers of E. mutata were absent in the putative hybrids. • CONCLUSIONS: Simultaneous use of various types of molecular markers can overcome many pitfalls of investigations concerning hybridization among closely related and morphologically similar species. Northern Belize represents a hybrid zone of E. cellulosa and E. interstincta. A third participant in the hybridization events occurring in this zone is an unknown Limnochloa lineage but is not E. mutata. Interspecific hybridization may play a significant role in the diversification of Eleocharis.
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natural hybridization in tropical spikerushes of Eleocharis subgenus limnochloa cyperaceae evidence from morphology and dna markers
American Journal of Botany, 2010Co-Authors: Eliska Rejmankova, Jan Kosnar, Miroslava Herbstova, Petr Macek, Milan StechAbstract:UNLABELLED PREMISE OF THE STUDY Natural hybridization represents an important force driving plant evolution and affecting community structure and functioning. Hybridization may be overlooked, however, among morphologically highly uniform congeners. An excellent example of such a group is Eleocharis subgenus Limnochloa, which has no reliably proven hybrids. Does this reflect biological barriers to interspecific crosses or difficulties in detecting the hybrids? We tested the hypothesis that hybridization occurs among sympatric Eleocharis cellulosa, E. interstincta, and E. mutata in northern Belize, Central America. • METHODS Morphometric study (407 plants) was followed by examination of inter-simple sequence repeat (ISSR) polymorphisms (44 plants) and ITS sequence variation (33 plants). • KEY RESULTS Two putatively hybrid morphotypes were discerned-E. cellulosa-resembling and E. interstincta-resembling. DNA markers of E. cellulosa and E. interstincta displayed additive constitution in plants from one E. cellulosa-resembling population only. The other putatively hybrid populations contained ISSR and ITS markers of the species they resembled morphologically, several unique ISSR markers, and ITS sequences of an undescribed South American Limnochloa entity. DNA markers of E. mutata were absent in the putative hybrids. • CONCLUSIONS Simultaneous use of various types of molecular markers can overcome many pitfalls of investigations concerning hybridization among closely related and morphologically similar species. Northern Belize represents a hybrid zone of E. cellulosa and E. interstincta. A third participant in the hybridization events occurring in this zone is an unknown Limnochloa lineage but is not E. mutata. Interspecific hybridization may play a significant role in the diversification of Eleocharis.
Cody E. Hinchliff - One of the best experts on this subject based on the ideXlab platform.
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Eleocharis endounifascis a new species of Eleocharis subgenus limnochloa cyperaceae from northern south america
Phytotaxa, 2013Co-Authors: Cody E. Hinchliff, Stephanie Petersen, Eric H RoalsonAbstract:A new species, Eleocharis endounifascis, is described and illustrated. This species inhabits standing water in disturbed, open habitats, occurring among a mosaic of wet forest, and probably also flourishes in sunny, seasonally inundated wetlands from Belize to southeastern Venezuela and Guyana to Brazil. It was previously confused with Eleocharis interstincta in herbarium collections and floristic works.
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phylogenetic relationships in Eleocharis cyperaceae c4 photosynthesis origins and patterns of diversification in the spikerushes
Systematic Botany, 2010Co-Authors: Eric H Roalson, Cody E. Hinchliff, Rafael Trevisan, Carlos Roberto Maximiano Da SilvaAbstract:Abstract Eleocharis (Cyperaceae) is a morphologically and physiologically diverse lineage of 250 + species with a cosmopolitan distribution. We here explore phylogenetic relationships in this lineage using maximum parsimony and Bayesian inference analyses of nrDNA ITS and cpDNA tmC-ycf6 and ycf6-psbM sequence data with the goals of comparing our phylogenetic hypotheses to previous classifications, morphological variation, and photosynthetic pathway variation. Our results suggest that in Eleocharis C4 photosynthesis has been derived at least three times, with several cases of possible reversion to C3-like or intermediate pathways and several additional origins of C3–C4 intermediate photosynthetic pathways, as inferred by carbon isotope ratio measurements. Many classification units currently recognized in Eleocharis are not monophyletic, however, E. subgenus Limnochloa and E. subgenus Scirpidium are monophyletic. Other classification units largely corresponding to clades include E. subgenus Zinserlingia, E....
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The origins of Eleocharis (Cyperaceae) and the status of Websteria, Egleria, and Chillania
TAXON, 2010Co-Authors: Cody E. Hinchliff, Ariel Lliully, Timothy Carey, Eric H RoalsonAbstract:Eleocharis R. Br. is an ecologically and economically important genus that contains about 250 species of annual and perennial sedges, with centers of diversity in seasonally wet tropical to subtropical regions. Phylogenetic relationships in the genus are poorly understood, particularly in relation to three monotypic genera—Egleria L.T. Eiten, Chillania Roivainen, and Websteria (Poir.) S. Hooper—which have been variously included or excluded from Eleocharis in different classifications. These genera, while morphologically distinct, show characteristics that fall within the range of variation seen in Eleocharis. The relationship between the clade containing Eleocharis and these segregate genera (i.e., Eleocharideae) and the rest of Cyperaceae has also been difficult to determine from previous studies, and numerous conflicting hypotheses have been suggested. To address these uncertainties, we sequenced cpDNA from the ndhF and psbB-psbH marker regions and used it to reconstruct the phylogenetic history of Eleocharis and a broad sample of other Cyperaceae. We found that Egleria and Websteria are derived from within Eleocharis, and that this clade, representing the Eleocharideae, is sister to the Abildgaardieae. Chillania could not be included in the molecular dataset, but its morphology suggests it should be included in Eleocharis. New nomenclature is suggested to place the species of Chillania, Egleria, and Websteria in Eleocharis. Our phylogenetic reconstructions also indicate several other instances of generic paraphyly in other Cyperaceae lineages.
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stem architecture in Eleocharis subgenus limnochloa cyperaceae evidence of dynamic morphological evolution in a group of pantropical sedges
American Journal of Botany, 2009Co-Authors: Cody E. Hinchliff, Eric H RoalsonAbstract:We examined phylogenetic relationships and patterns of stem structural evolution in Eleocharis subgenus Limnochloa , an ecologically and economically important group of tropical to temperate-growing sedges, whose stems serve as the primary photosynthetic organs. We used maximum parsimony, likelihood, and Bayesian inference to develop phylogenetic trees and stochastic mapping and a Markov one-rate model to develop character history reconstructions of stem architecture. A complex history of stem shape evolution characterized by a high degree of homoplasy and rapid rates of change (an average of 13 transitions per character history for about 25 species) was identifi ed across subgenus Limnochloa . Character states transition much more frequently in some lineages than others, but tend to follow a consistent directional pattern of evolutionary change. Our data also suggest that changes in stem shape and anatomy may be associated with speciation events in the subgenus (Pagel ’ s κ = 0.3503, P = 0.04579) and may have some adaptive signifi cance. The potential adaptive roles of stem structural traits are unclear, but may be elucidated by further studies. This work serves as a starting point for future evolutionary studies of stem shape and structure in monocots and provides important background knowledge for further studies of ecological adaptations of Eleocharis .
Milan Stech - One of the best experts on this subject based on the ideXlab platform.
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natural hybridization in tropical spikerushes of Eleocharis subgenus limnochloa cyperaceae evidence from morphology and dna markers
American Journal of Botany, 2010Co-Authors: Eliska Rejmankova, Jan Kosnar, Miroslava Herbstova, Petr Macek, Milan StechAbstract:PREMISE OF THE STUDY: Natural hybridization represents an important force driving plant evolution and affecting community structure and functioning. Hybridization may be overlooked, however, among morphologically highly uniform congeners. An excellent example of such a group is Eleocharis subgenus Limnochloa, which has no reliably proven hybrids. Does this reflect biological barriers to interspecific crosses or difficulties in detecting the hybrids? We tested the hypothesis that hybridization occurs among sympatric Eleocharis cellulosa, E. interstincta, and E. mutata in northern Belize, Central America. • METHODS: Morphometric study (407 plants) was followed by examination of inter-simple sequence repeat (ISSR) polymorphisms (44 plants) and ITS sequence variation (33 plants). • KEY RESULTS: Two putatively hybrid morphotypes were discerned-E. cellulosa-resembling and E. interstincta-resembling. DNA markers of E. cellulosa and E. interstincta displayed additive constitution in plants from one E. cellulosa-resembling population only. The other putatively hybrid populations contained ISSR and ITS markers of the species they resembled morphologically, several unique ISSR markers, and ITS sequences of an undescribed South American Limnochloa entity. DNA markers of E. mutata were absent in the putative hybrids. • CONCLUSIONS: Simultaneous use of various types of molecular markers can overcome many pitfalls of investigations concerning hybridization among closely related and morphologically similar species. Northern Belize represents a hybrid zone of E. cellulosa and E. interstincta. A third participant in the hybridization events occurring in this zone is an unknown Limnochloa lineage but is not E. mutata. Interspecific hybridization may play a significant role in the diversification of Eleocharis.
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natural hybridization in tropical spikerushes of Eleocharis subgenus limnochloa cyperaceae evidence from morphology and dna markers
American Journal of Botany, 2010Co-Authors: Eliska Rejmankova, Jan Kosnar, Miroslava Herbstova, Petr Macek, Milan StechAbstract:UNLABELLED PREMISE OF THE STUDY Natural hybridization represents an important force driving plant evolution and affecting community structure and functioning. Hybridization may be overlooked, however, among morphologically highly uniform congeners. An excellent example of such a group is Eleocharis subgenus Limnochloa, which has no reliably proven hybrids. Does this reflect biological barriers to interspecific crosses or difficulties in detecting the hybrids? We tested the hypothesis that hybridization occurs among sympatric Eleocharis cellulosa, E. interstincta, and E. mutata in northern Belize, Central America. • METHODS Morphometric study (407 plants) was followed by examination of inter-simple sequence repeat (ISSR) polymorphisms (44 plants) and ITS sequence variation (33 plants). • KEY RESULTS Two putatively hybrid morphotypes were discerned-E. cellulosa-resembling and E. interstincta-resembling. DNA markers of E. cellulosa and E. interstincta displayed additive constitution in plants from one E. cellulosa-resembling population only. The other putatively hybrid populations contained ISSR and ITS markers of the species they resembled morphologically, several unique ISSR markers, and ITS sequences of an undescribed South American Limnochloa entity. DNA markers of E. mutata were absent in the putative hybrids. • CONCLUSIONS Simultaneous use of various types of molecular markers can overcome many pitfalls of investigations concerning hybridization among closely related and morphologically similar species. Northern Belize represents a hybrid zone of E. cellulosa and E. interstincta. A third participant in the hybridization events occurring in this zone is an unknown Limnochloa lineage but is not E. mutata. Interspecific hybridization may play a significant role in the diversification of Eleocharis.
Eliska Rejmankova - One of the best experts on this subject based on the ideXlab platform.
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macrophyte root and rhizome decay the impact of nutrient enrichment and the use of live versus dead tissue in decomposition studies
Biogeochemistry, 2015Co-Authors: Jenise M Snyder, Eliska RejmankovaAbstract:The decomposition of roots and rhizomes of two macrophytes, Eleocharis cellulosa and Typha domingensis, was studied in oligotrophic phosphorus (P) limited marshes of northern Belize. The experiment was conducted in long-term control and P enriched plots in five limestone-based inland marshes. Decomposition of naturally senescent root and rhizome litter was studied over 9 months using litterbags. Belowground litter was acquired by growing plants in unenriched (control) or P enriched marsh soils for 5 months. Plants were then allowed to naturally senesce using a split root design, which promoted nutrient retranslocation. The resulting senescent litter had 30 % higher C:P and 40 % lower P content than living roots and rhizomes. There were no differences in C:N among treatments or senescent versus live litter. Litterbags, filled with control or enriched root and rhizome litter, were buried in the upper 10–14 cm soil in the corresponding plot of each marsh. Differences in the rate of decay between species were greatest for rhizome tissue, with Typha decaying more than twice as fast as Eleocharis. For both species, however, tissue P enrichment had no effect on coarse root and rhizome decay. Enhanced root production from P enrichment, coupled with no change in decay, should lead to enhanced accretion over time. Additional tests, using litterbags filled with living roots and rhizomes, yielded dramatically different results between treatments compared to senescent tissue. Results from senescent belowground tissue also differed from shoot decomposition. Caution should be exercised when inferring belowground decomposition from live tissue and aboveground rates of decay.
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natural hybridization in tropical spikerushes of Eleocharis subgenus limnochloa cyperaceae evidence from morphology and dna markers
American Journal of Botany, 2010Co-Authors: Eliska Rejmankova, Jan Kosnar, Miroslava Herbstova, Petr Macek, Milan StechAbstract:PREMISE OF THE STUDY: Natural hybridization represents an important force driving plant evolution and affecting community structure and functioning. Hybridization may be overlooked, however, among morphologically highly uniform congeners. An excellent example of such a group is Eleocharis subgenus Limnochloa, which has no reliably proven hybrids. Does this reflect biological barriers to interspecific crosses or difficulties in detecting the hybrids? We tested the hypothesis that hybridization occurs among sympatric Eleocharis cellulosa, E. interstincta, and E. mutata in northern Belize, Central America. • METHODS: Morphometric study (407 plants) was followed by examination of inter-simple sequence repeat (ISSR) polymorphisms (44 plants) and ITS sequence variation (33 plants). • KEY RESULTS: Two putatively hybrid morphotypes were discerned-E. cellulosa-resembling and E. interstincta-resembling. DNA markers of E. cellulosa and E. interstincta displayed additive constitution in plants from one E. cellulosa-resembling population only. The other putatively hybrid populations contained ISSR and ITS markers of the species they resembled morphologically, several unique ISSR markers, and ITS sequences of an undescribed South American Limnochloa entity. DNA markers of E. mutata were absent in the putative hybrids. • CONCLUSIONS: Simultaneous use of various types of molecular markers can overcome many pitfalls of investigations concerning hybridization among closely related and morphologically similar species. Northern Belize represents a hybrid zone of E. cellulosa and E. interstincta. A third participant in the hybridization events occurring in this zone is an unknown Limnochloa lineage but is not E. mutata. Interspecific hybridization may play a significant role in the diversification of Eleocharis.
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natural hybridization in tropical spikerushes of Eleocharis subgenus limnochloa cyperaceae evidence from morphology and dna markers
American Journal of Botany, 2010Co-Authors: Eliska Rejmankova, Jan Kosnar, Miroslava Herbstova, Petr Macek, Milan StechAbstract:UNLABELLED PREMISE OF THE STUDY Natural hybridization represents an important force driving plant evolution and affecting community structure and functioning. Hybridization may be overlooked, however, among morphologically highly uniform congeners. An excellent example of such a group is Eleocharis subgenus Limnochloa, which has no reliably proven hybrids. Does this reflect biological barriers to interspecific crosses or difficulties in detecting the hybrids? We tested the hypothesis that hybridization occurs among sympatric Eleocharis cellulosa, E. interstincta, and E. mutata in northern Belize, Central America. • METHODS Morphometric study (407 plants) was followed by examination of inter-simple sequence repeat (ISSR) polymorphisms (44 plants) and ITS sequence variation (33 plants). • KEY RESULTS Two putatively hybrid morphotypes were discerned-E. cellulosa-resembling and E. interstincta-resembling. DNA markers of E. cellulosa and E. interstincta displayed additive constitution in plants from one E. cellulosa-resembling population only. The other putatively hybrid populations contained ISSR and ITS markers of the species they resembled morphologically, several unique ISSR markers, and ITS sequences of an undescribed South American Limnochloa entity. DNA markers of E. mutata were absent in the putative hybrids. • CONCLUSIONS Simultaneous use of various types of molecular markers can overcome many pitfalls of investigations concerning hybridization among closely related and morphologically similar species. Northern Belize represents a hybrid zone of E. cellulosa and E. interstincta. A third participant in the hybridization events occurring in this zone is an unknown Limnochloa lineage but is not E. mutata. Interspecific hybridization may play a significant role in the diversification of Eleocharis.