Systematics and evolution of sections of the subgenus <Emphasis Type="Italic">Rohrbachia</Emphasis> (Kronf. ex Riedl) A. Krasnova of the hydrophilic genus <Emphasis Type="Italic">Typha</Emphasis> L. (Typhaceae) in Eurasia

Systematics of the three modern sections of the subgenus Rohrbachia of the genus Typha (Typhaceae) and reconstruction of evolution in different geological periods of the Cenozoic Era in Eurasia have been examined. The section Minimae was formed in the Paleogene (Eocene) on littorals of the Angarida–Beringian area; the sections Turanicae and Mongolica were formed on the border of the Paleogene–Neogene in Central Asia (Middle Asia, North China, and Manchuria).     

Interspecific differences in radial oxygen loss from the roots of three <Emphasis Type="Italic">Typha</Emphasis> species

A comparison was made of the radial oxygen loss (ROL) from the roots of three Typha species, Typha latifolia L., Typha orientalis Presl and Typha angustifolia L., which resemble each other in morphology. ROLs were evaluated in the laboratory for seedlings of T. orientalis and T. angustifolia in order to compare them with the ROL value for T. latifolia obtained in our previous study. Measurements were conducted using the highly oxygen-sensitive anthraquinone radical anion as an oxygen indicator, which enabled us to simulate the natural conditions in which the oxygen released from the root is immediately consumed by the soil. Among the three Typha species, the ROL was the highest in T. angustifolia, followed by T. latifolia and T. orientalis. Illumination significantly enhances the ROL of T. orientalis, and this effect was also observed for T. latifolia in our previous study, whereas it did not affect the ROL of T. angustifolia. These results indicate that ROL differs significantly between species, even among members of the same genus that are similar in morphology.     

On the systematics of section Engleria (Leonova) Tzvel. of hydrophilic genus <Emphasis Type="Italic">Typha</Emphasis> L.

As a result of a comparative and morphological analysis of the collection material of the herbaria of the Botanical Institute at the Russian Academy of Sciences (St. Petersburg, LE) and the Institute of Botany at the National Academy of Sciences of Ukraine (Kiev, KW), as well as herbarium materials from Irkutsk (Popov IRK herbarium) and Tomsk (Krylov TK herbarium); our own collected materials; and an analysis of literature data on hydrophilic genus Typha L., taxa of the section of Engleria (Leonova) Tzvel T. laxmannii Lepech., T. laxmannii var. getica Morariu, T. taxmannii var. bungei Krasnova & Durnikin, T. laxmannii var. turczaninovii Krasnova & Durnikin, T. veresczaginii Kryl. & Schischk., T. zerovii Klok fil. & A. Krasnova, T. pontica Klok. Fil. & A. Krasnova, and T. przewalskii Skvortsov, the subsection Mandshuriae A. Krasnova is described.     

Effects of experimental harvesting of an invasive hybrid cattail on wetland structure and function

Invasive plants, such as the hybrid cattail Typha × glauca, can reduce biodiversity and alter the ability of wetlands to provide critical ecosystem services, including nutrient cycling and carbon storage. Several approaches have been used to reduce Typha dominance and restore invaded wetlands, but long‐term studies assessing benefits of these restoration efforts are limited. A previous study demonstrated that aboveground harvesting of Typha × glauca stems and litter reduced Typha dominance 2 years post‐treatment in a Great Lakes coastal wetland. In the current study, we extended monitoring of experimental aboveground Typha harvest to 4 years post‐treatment and added assessments of treatment effects on soil nutrients, carbon emissions, and microbial community composition. Aboveground harvest treatment resulted in a dramatic reduction in Typha litter cover that persisted for 4 years, increased soil temperature, and increased abundance of the native plant genus Carex. However, aboveground harvest treatment did not significantly reduce Typha abundance, nor did it have significant effects on soil nutrient concentrations, carbon fluxes, or the taxonomic composition of soil microbial communities. We did observe differences in bacterial community composition between plots based on time since Typha invasion, which may indicate some legacy effects of Typha invasion. At the scale of this experiment (4 × 4 m plots), our results indicate that a single aboveground removal of Typha × glauca is not sufficient to restore a heavily invaded freshwater wetland ecosystem, and that periodic harvesting of Typha stems and litter may be required to maintain native plant abundance.     

Anomalies of broad-leaved cattail (<Emphasis Type="Italic">Typha</Emphasis> L., Typhaceae) in a small anthropogenic pond of the Upper Volga basin

An increased anthropogenic impact on the hydrophilic ecosystems of technogenic ponds of the Volga–Caspian basin has enhanced the migration of Typha latifolia L. and closely related species. Due to backcrossings and anomalies among bractless sections of the genus Typha, new morphological traits have been formed in T. latifolia via the stage of a nonspecific form development. Morphological anomalies revealed in an association of Typhetum latifoliae Soó 1927 of a small anthropogenic pond in the Yaroslavl region have been studied.     

Cultural Disturbances and Local Ecological Knowledge Mediate Cattail (<Emphasis Type="Italic">Typha domingensis</Emphasis>) Invasion in Lake Pátzcuaro,México

The influence of local actors and socioeconomic constraints on biological invasions is often ignored. Wetland plant harvesters appeared to intentionally influence cattail (Typha domingensis) invasion around Lake Pátzcuaro, México, by altering their harvesting regimes, according to interviews with 44 expert respondents and botanical surveys. The oldest and most experienced harvesters reported controlling Typha initially, sometimes through organized eradication efforts, in order to protect Schoenoplectus californicus, an economically and culturally valuable wetland plant. Later, outsiders commoditized Typha by introducing new weaving designs popular with tourists, while industrial products and new livelihood activities reduced Schoenoplectus harvest. Harvesters from several communities began to promote Typha re-growth. Some harvesters, however, continued to combat Typha to maintain Schoenoplectus production, especially where supply was limited. Interviews suggested novel ecological cause–effect mechanisms and restoration strategies; some local harvesting regimes could efficiently conserve rare plants. An understanding of local ecological knowledge and incentives can inform invasive species control and conservation policy at a broader scale.     

Effect of experimental phosphorus enrichment on oligotrophic tropical marshes in Belize,Central America

Sedges from genus Eleocharisdominate extensive wetlands in the sugar cane growing areas of the Caribbean. Correlative data suggest that macrophytes in these wetlands are phosphorus limited. To determine effects of increased P input that can be expected, e.g. from agricultural runoff, a common sugar cane fertilizer was applied to representative plots in four marl-based and four peat-based marshes. The plots were located in the proximity of patches of Typha domingensis, which has been reported to be able to outcompete Eleocharis under nutrient rich conditions. Responses to the fertilizer treatment were documented as changes in: Plant height, density, biomass, net primary production, nutrient resorption, decomposition, plant and soil nutrient concentrations, percent cover of cyanobacterial mats, and potential colonization by Typha. Additions of phosphorus significantly increased plant density and height and, consequently, the aboveground net primary production. Phosphorus resorption efficiency following senescence was independent of fertilizer addition in Eleocharis but decreased in Typha from the fertilized plots. Phosphorus resorption proficiency was lower in fertilized plots for both Typha and Eleocharis. Decomposition of litter and cellulose assays was significantly faster in fertilized plots. No spontaneous establishment of Typha occurred in the fertilized plots, but survival of transplanted Typha was higher in fertilized plots than in controls. Increased plant density in fertilized plots led to elimination of a key component of these ecosystems, the nitrogen fixing cyanobacterial mats.     

Expansion of <Emphasis Type="Italic">Phragmites australis</Emphasis> (Cav.) Trin. ex Steud. (Common Reed) into <Emphasis Type="Italic">Typha</Emphasis> spp. (Cattail) Wetlands in Northwestern Indiana,USA

Expansion of Phragmites australis (Cav.) Trin. ex Steud. (common reed) into stands of Typha spp. (cattail; Typha australis L. and T. x glauca) is common in the wetlands of northwestern Indiana (USA). To understand this phenomenon better, we investigated the production of shoot sprouts and proportional allocation of biomass as well as a potential role for the water table in the relative dominance of each species. The reduction in sprouts from rhizomes upon vegetative expansion of Phragmites appeared to be the most likely process causing the decline of Typha. The latter had a shoot density of 39/m² in plots without Phragmites, but this dropped to 13 shoots m⁻² in plots that had been invaded by Phramites. Such a decline was likely caused by reduced reserves; e.g., the belowground biomass of Typha decreased from 11.3 g m⁻² without Phragmites to 8.1 g m⁻² with Phragmites. The latter also reduced its belowground biomass but not its shoot density in the presence of Typha. The mean weight of Phragmites shoots was 2.9 g, and nearly all produced inflorescences. Meanwhile, Typha failed to develop spadices despite its shoots having a greater biomass (7 g). This suggests that Phragmites is more efficient than Typha in shoot growth. Springtime flooding appeared to promote the sprout of Typha shoots from shallow rhizomes (≈18 cm below the soil surface), whereas the shoot density of Phragmites showed no correlation with water level in that season. Deep-rooted Phragmites (≈39 cm) occurred on both high and low water-table sites, whereas the shallow-rooted Typha was limited to only the former. Phragmites will likely continue its expansion, by vegetative sprouts from rhizomes, into Typha wetlands.     

Aquatic plants diversity in arid zones of Northwest China: patterns, threats and conservation

We investigated aquatic plant diversity by conducting the field investigation and collecting the published data in the arid regions of Northwest China. Two hundred and twenty four taxa of vascular aquatic plants representing 64 genera and 34 families occur in this area, 8.48% of which are endemic. Among these, 1 genus and 6 species were new state records and 1 family, 9 genera and 29 species were new area records. Typhaceae, Potamogetonaceae, Juncaginaceae and Haloragaceae were the most frequent families (considering relative frequency of occurrence), whereas Cyperaceae, Potamogetonaceae and Ranuncnlaceae are the most species-rich. The most frequent genera were Typha, Potamogeton, and Triglochin, and the most species-rich were Potamogeton, Eleocharis and Scirpus. The most frequent species are Triglochin palustre, Myriophyllum spicatum, Potamogeton pectinatus and Typha angustifolia. Aquatic plants diversity is distributed unevenly in the region. The maximum species occurs in Dzungarian basin while the least species in Hexi corridor. The aquatic flora in arid zone of China is not distinctive although some endemic species are found, most species are widely distributed. Local aquatic plants diversity can be influenced by many factors such as hydrological alteration, habitat loss, over-grazing, high human population pressure, global climate change, an inappropriate economic development policy. Among them, the largest threat to aquatic plants biodiversity may be habitat loss due to hydrological alteration. In order to conserve the aquatic plants biological resources and biodiversity in this region, some strategies and measures must be suggested including strengthening scientific research and biodiversity education in the local people, balancing economic development and ecological conservation, and enhancing governmental assistance and subsidy to the local residents.     

Evaluation of AFLP markers to reveal genetic diversity in Typha

We investigated to what extent DNA-markers can assist species determination in the genus Typha. A set of AFLP markers was used to discriminate samples of the species Typha latifolia and Typha angustifolia collected in Flanders (North Belgium). The T. latifolia samples formed a compact cluster while the T. angustifolia samples were divided into smaller groups. It was not clear whether interspecific hybrids or higher levels of diversity present in the T. angustifolia dataset could account for this. As in previous surveys, using isozyme and VNTR markers, AFLP markers revealed an almost complete lack of genetic variation in Flemish T. latifolia. Despite the low degree of diversity, a significant level of genetic differentiation was found between the T. latifolia samples originating from different river basins. Whether this differentiation has any ecological relevance remains to be investigated. The methodology applied was not able to detect clonal reproduction in T. latifolia. Probably, the low levels of diversity present in this species can account for this, indicating that the usefulness of the methodology applied depends on the level of diversity present in the species studied.     

Molecular phylogenetics of Paphiopedilum (Cypripedioideae; Orchidaceae) based on nuclear ribosomal ITS and plastid sequences

Phylogenetic relationships in the genus Paphiopedilum were studied using nuclear ribosomal internal transcribed spacer (ITS) and plastid sequence data. The results confirm that the genus Paphiopedilum is monophyletic, and the division of the genus into three subgenera Parvisepalum, Brachypetalum and Paphiopedilum is well supported. Four sections of subgenus Paphiopedilum (Pardalopetalum, Cochlopetalum, Paphiopedilum and Barbata) are recovered as in a recent infrageneric treatment, with strong support. Section Coryopedilum is also recovered, with low bootstrap but high posterior probability values for support of monophyly. Relationships in section Barbata remain unresolved, and short branch lengths and the narrow geographical distribution of many species in the section suggest that it possibly underwent rapid radiation. Mapping chromosome and genome size data (including some new genome size measurements) onto the phylogenetic framework shows that there is no clear trend in increase in chromosome number in the genus. However, the diploid chromosome number of 2n = 26 in subgenera Parvisepalum and Brachypetalum suggests that this is the ancestral condition, and higher chromosome numbers in sections Cochlopetalum and Barbata suggest that centric fission has possibly occurred in parallel in these sections. The trend for genome size evolution is also unclear, although species in section Barbata have larger genome sizes than those in other sections. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170 , 176–196.     

Gas chromatography mass spectrometry based profiling of alkyl coumarates and ferulates in two species of cattail (Typha domingensis P., and Typha latifolia L.)

Several long-chain n-alkyl coumarates and ferulates were identified in cattails (Typha domingensis and Typha latifolia) from the Florida Everglades. Characterization of these compounds was achieved based on the interpretation of mass spectra obtained by GCMS as their trimethylsilyl ether derivatives, comparison with published mass spectra and available standards. Both n-alkyl p-coumarates and n-alkyl ferulates were identified in roots and leaves of both Typha species, featuring unique distribution patterns and differences between leaf and root biomass. For both Typha species, roots have higher concentrations and a much greater diversity of n-alkyl p-coumarates and ferulates but with different side chain carbon numbers ranging from C₁₄ to C₂₈. Typha domingensis leaves only contained n-alkyl ferulates with traces of n-alkyl p-coumarates, while both types of compounds were present in Typha latifolia leaf material. These chemicals were not found in the other dominant wetland vegetation, which suggests their potential for application as phytochemical tracers of fresh cattail-derived organic matter in the Everglades ecosystem.     

PHYLETIC TRENDS IN SECTIONS EUBLEPHARIS AND CALLIOPSIS OF THE GENUS COREOPSIS (COMPOSITAE)

Artificial hybridization, fertility of interspecific and intersectional hybrids, chromosome numbers, and trends in habit and morphology in taxa of sections Eublepharis and Calliopsis of the genus Coreopsis are used to consider the sectional relationships and to derive a presumed phylogeny for the two sections. The two sections are closely related and show a low level of interfertility, but this level is as high as in some interspecific crosses within sections. The sections differ in base chromosome number and achene winging. The problematic C. rosea evidently should remain in section Eublepharis. Both sections probably arose from x = 13 stock resembling C. integrifolia or C. pubescens. Descending aneuploidy was involved in the derivation of section Calliopsis, while chromosome evolution in section Eublepharis has involved polyploidy.     

Can differences in phosphorus uptake kinetics explain the distribution of cattail and sawgrass in the Florida Everglades?

Background  

Cattail (Typha domingensis) has been spreading in phosphorus (P) enriched areas of the oligotrophic Florida Everglades at the expense of sawgrass (Cladium mariscus spp. jamaicense). Abundant evidence in the literature explains how the opportunistic features of Typha might lead to a complete dominance in P-enriched areas. Less clear is how Typha can grow and acquire P at extremely low P levels, which prevail in the unimpacted areas of the Everglades.     

Phylogenetic relationships in the genus <Emphasis Type="Italic">Primula</Emphasis> L. (Primulaceae) inferred from the ITS region sequences of nuclear rDNA

The nucleotide sequences of the nuclear rDNA ITS regions were determined for 34 species of the genus Primula L. and one species of the genus Cortusa L., family Primulaceae Vent., and used to infer the phylogenetic relationships among these species. In this analysis species of the Russian flora and the flora of adjacent territories were studied for the first time. The results clarified the taxomic structure of the genus Primula and confirmed the entity of some of its sections; but not the subgenera sensu J.Richards. Our data do not support an independent status of the genus Cortusa, placing it as one of the terminal lineages of the section Cortusoides Balf. f. in the genus Primula.     

CHROMOSOME NUMBERS IN CUPHEA (LYTHRACEAE): NEW COUNTS AND A SUMMARY

The American genus Cuphea with ca. 260 species is extremely diverse with respect to chromosome number. Counts are now available for 78 species and/or varieties, or 29% of the genus. Included in this study are first reports for 15 taxa from Brazil, Cuba, Dominican Republic, Mexico, and Venezuela. Twenty-two different numbers are known for the genus, ranging from n = 6 to n = 54. The most common number in the primary center of species diversity in Brazil is n = 8, which is regarded as the base number of the genus. Two numbers are most common in the secondary center in Mexico, n = 10 and n = 12. Species with n = 14 or higher are considered to be of polyploid origin. Polyploids comprise 46% of the total species counted and appear in 9 of the 11 sections for which chromosome numbers have been reported. Aneuploid species comprise ca. 25% of the genus and are known from 7 of the 11 sections. The two subgenera are not characterized by different chromosome numbers or sequences of numbers. None of the 14 sections are circumscribed by a single chromosome number. Morphological and ecological variability in widespread, weedy species is correlated with differing chromosome numbers in some species whereas in others the chromosome number is stable. Summary of chromosome numbers by taxonomic section is presented. Section Euandra, centered in eastern Brazil, and the largest section of the genus, appears to be chromosomally most diverse. In section Trispermum, characterized by difficult, variable species with intermediate forms, two of the four species studied have polyploid races. Section Heterodon, endemic to Mexico and Central America and comprising most of the annual species of the genus, is best known chromosomally. Chromosome numbers have been counted for 25 of 28 species, and 12 different numbers are reported. The most advanced sections, Melvilla and Diploptychia, with numerous species occurring at higher altitudes, are characterized by high polyploids. Apomictic species occur in sect. Diploptycia. The cytoevolution of Cuphea is complex with frequent polyploid and aneuploid events apparently playing a significant role in speciation in both centers of diversity.     

Teratomorphs of broad-leaved cattail <Emphasis Type="Italic">Typha latifolia</Emphasis> L. in Vozhe Lake

Morphological anomalies such as hypogenesia, dystopia, and polymerization have been found and classified in communities of the broad-leaved cattail Typheta latifoliae in the specific species Typha latifolia L. in technogenically disturbed habitats of Vozhe Lake. Anomalies have also been found in other specific species in the most widespread communities of Vologda Poozer’e, such as Phramitetum australis subpurum and Typheta angustifoliae subpurum. This testifies to the deep changes in hydrophilic flora under anthropogenic influences. The tendency to teratological speciation appears in natural conditions in pure communities of Phramitetum australis, Typheta angustifoliae, and Typheta latifoliae on the northern border of coenotic and ecological areals.     

Long-term effects of prescribed fire on Cladium jamaicense crantz and Typha domingensis pers. densities

The importance of fire to the maintenance of herbaceous plant communities in Florida wetland ecosystems is widely acknowledged. However, despite the acceptance of fire as a natural and necessary disturbance, ecosystem responses to fire in these systems are still poorly understood. Of particular concern is the effect of fire on the dynamics of plant communities dominated by Cladium jamaicense Crantz and Typha domingensis Pers. High nutrient levels, primarily phosphorus, and prolonged hydroperiods have been associated with Typha expansion into Cladium dominated communities. Recent studies suggest that fire is a disturbance that may play a facilitative role in this process. The objective of this study was to monitor the long-term effects of a single prescribed fire on Cladium and Typha densities in a freshwater marsh in Florida. Transects located at two burned sites and one unburned site were sampled prior to and annually for four years following a prescribed, lightning-season fire. There was a significant increase (P < 0.01) in Typha at both burn sites for two years after the fire. However, this increase was temporary since Typha density declined to pre-burn levels in the third and fourth years post-burn. Cladium density at the burned sites either increased or remained unchanged throughout the study period. When the control site unexpectedly burned in the fourth year of the study, density changes of Typha were similar to those observed at the original burn sites. Overall, we did not see any lasting changes in Cladium and Typha as a result of the fires, even though soil nutrient levels and hydroperiods were within levels documented to enhance Typha expansion.     

Does sulphate enrichment promote the expansion of Typha domingensis (cattail) in the Florida Everglades?1

1. The expansion of Typha domingensis into areas once dominated by Cladium jamaicense in the Florida Everglades has been attributed to altered hydrology and phosphorus enrichment, although increased concentrations of sulphate and phosphorus often coincide. The potential importance of hydrogen sulphide produced from sulphate in the expansion of Typha has received little attention. The present study aimed to quantify the comparative growth and photosynthetic responses of Cladium and Typha to sulphate/sulphide. 2. Laboratory experiments showed that Cladium is less tolerant of sulphide than Typha. Cladium was adversely affected at sulphide concentrations of approximately 0.22 mm , while Typha continued to grow well and appeared healthy up to 0.69 mm sulphide. 3. Experiments in field mesocosms provided strong support for species‐specific differences in physiology and growth. Regardless of interstitial sulphide concentrations attained, Typha grew faster and had a higher photosynthetic capacity than Cladium. However, sulphide concentrations in the mesocosms reached only 0.18 mm which, based on the hydroponic study, was insufficient to affect the growth or photosynthetic responses of either species. Nevertheless, the upper range of sulphide (0.25–0.375 mm ) in Everglades’ soil is high enough, based on our results, to impact Cladium but not Typha. 4. This research supports the hypothesis that sulphide accumulation could affect plant species differentially and modify species composition. Consequently, the role of sulphate loading should be considered, in conjunction with hydroperiod, phosphorus availability and disturbances, in developing future management plans for the Everglades.     

Constraints on Sedge Meadow Self‐Restoration in Urban Wetlands

Invasive plants and urban run‐off constrain efforts to restore sedge meadow wetlands. We asked if native graminoids can self‐restore following the removal of Typha × glauca (hybrid cattail), and if not, what limits their recovery? After we harvested Typha and depleted its rhizome starch reserves, Carex spp. expanded vegetatively (approximately 1 m over 2 years) but not by recruiting seedlings. A seedling emergence experiment showed that seed banks were depleted where Typha had eliminated the sedge meadow over a decade ago (based on aerial photo analysis). Carex seedling emergence was 75–90% lower where Carex was absent than where it remained in the plant community, and at least 17 species that were abundant 30 years ago were absent from the seed bank and extant vegetation. By varying hydroperiod, we showed that prolonged flooding prevented emergence of Carex seedlings and that a fluctuating hydroperiod reduced emergence and ultimately killed all Carex seedlings. In contrast, Typha seedlings emerged and survived regardless of hydroperiod. Thus, slow vegetative expansion by Carex, depauperate seed banks, and altered hydroperiods all constrain self‐restoration. To compensate for multiple constraints on self‐restoration, we recommend a long‐term management approach that capitalizes on flooding and the capacity of Carex spp. to regrow vegetatively. We suggest annually harvesting swaths of Typha at the edges of clones, before or during flood events, to allow gradual, vegetative self‐restoration of Carex spp.