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Callitriche is a sub-cosmopolitan plant genus occurring throughout temperate regions of both hemispheres, including the peri-Antarctic islands, with 78 species worldwide. Records of Callitriche include frequent and extensive misidentification due to a combination of factors including a lack of taxonomic and nomenclatural clarification before the mid-20th century. This work aims to contribute to the taxonomic knowledge of the genus Callitriche in South America by presenting taxonomic novelties and a revision of some critical species. More specifically, seven new species are described: C. ciliata, C. concinna, C. dacryoidea, C. ecarinata, C. hegelmaieriana, C. praetermissa and C. schotsmaniana. In addition, C. marginata var. berteroana is here raised to species rank, C. mandonis, C. oblongicarpa and C. turfosa are re-established, and the names C. antarctica, C. deflexa, C. deflexa var. brauniana, C. deflexa var. glaziovii, C. deflexa var. phaeocarpa, C. heterophylla, C. heteropoda, C. terrestris and C. turfosa are typified.

This article presents information on the distribution and ecology of Callitriche species in Morocco, based on field survey, literature review, and examination of herbarium specimens. Taxa reported erroneously from the country are discussed and new information is presented on the morphology of C. mathezii and C. truncata subsp. truncata.

We present current information on the conservation of aquatic vascular plants in West and East Siberia and the Russian Far East. This includes the region from the Ural Mountains in the west to the eastern seaboard of Russia from Kamchatka and Chukotka in the north to Vladivostok in the south, including Sakhalin, the Kuril and Commander Islands. A list of aquatic vascular plant species protected in the region is presented with an indication of their conservation status derived from regional Red Data Books, combined with population trend data from the literature, as well as field observations made by the authors. The region as a whole supports a total of 246 aquatic plant species, of which 96 are listed as threatened in regional Red Lists. The main threats to these species are habitat degradation, eutrophication and pollution of water bodies as a consequence of human activity and climate change. Many species which are specialized, relict or endemic, and others occurring here on the edge of their range, are vulnerable because of these factors. The main conservation action needed includes protection of natural habitats, establishment of monitoring protocols for the most severely threatened species and research into the autecology of threatened species. There is also a need to resolve taxonomic questions obstructing conservation.

Bolboschoenus laticarpus Marhold, Hroudová, Zákravský & Ducháček (for which we suggest the common name Pedunculate Club-rush) is reported from the British Isles and the characters which distinguish it from B. maritimus (L.) Palla are given. The known English distribution is presented and placed in its wider geographical context. The ecology and history of this species in Britain are outlined and its likely status is considered. B. laticarpus is locally abundant and widely distributed in a range of natural and artificial habitats, particularly within the Somerset Levels and also in the flood plains of some larger rivers, where it is now known to have been long persistent. B. laticarpus appears to be a successful colonist, having arrived recently in several newly created, artificial habitats. The mode of introduction is unknown but believed to be natural, and indeed elsewhere in Europe it is reportedly increasing within its natural range, perhaps as a consequence of changes in land-use, eutrophication and potentially climate. We therefore regard it as a native taxon.

The article presents the results of a study of the ligule morphology of both vegetative and reproductive leaves of four species of Selaginella, i.e. S. delicatula, S. ganguliana, S. plana and S. tenera, occurring in India. Ligules of S. ganguliana, S. plana and S. tenera are described for the first time, and the occurrence of shuttlecock-like ligules is described for the first time. Ligule shape is generally constant across the species studied but some minor morphological variations are observed within species. However, in combination with other morphological characters, the ligule may be a useful tool in the taxonomic delimitation of closely related Selaginella species. In addition, we propose that ligule size may be influenced by the habitat conditions, whereas the presence of glandular cells at their tip margins possibly indicate a water secreting function.

Intermediates between Schoenoplectus lacustris and S. tabernaemontani have been recognised at least since the late 19th century and for much of that time, there has been speculation that such intermediates may involve hybridisation. In 2017 the hybrid status of a population growing in the South-Forty-foot Drain in Lincolnshire was confirmed using molecular tools. This article presents information on the hybrid, both from the Lincolnshire population and from the literature, as well as providing an indication of how hybrid populations might be recognised. The binomial Schoenoplectus × flevensis (D.Bakker) Lansdown & Rumsey is proposed for the hybrid.

Callitriche is a genus of small herbs, ranging from aquatic to amphibious and terrestrial, the taxonomy of the genus is complicated and still unresolved, and knowledge of species distribution is st...

Additional detail is provided to validate the new combination Schoenoplectus × flevensis (D.Bakker) Lansdown & Rumsey comb. & stat. nov.

New information has extended the known range of Callitriche pulchra Schotsm. (Plantaginaceae) to Cyprus. This, combined with a survey of populations on the island of Gavdos off the S coast of Crete, shows that it is less threatened than previously thought. Updated information is presented here on the distribution, status and ecology of this species. Citation: Lansdown R. V., Kefalas K. & Bazos I. 2016: New information on the status and distribution of Callitriche pulchra (Plantaginaceae), including a first record from Cyprus. — Willdenowia 46: 379–385. doi: http://dx.doi.org/10.3372/wi.46.46306 Version of record first published online on 3 November 2016 ahead of inclusion in December 2016 issue.

In recent years, awareness has risen surrounding the crucial role of plants in providing ecosystem services and on their decline – they are one of the essential foundations of healthy ecosystems that we depend on. However, significant gaps in knowledge still remain. In this context, the European Red List of lycopods and ferns provides the first ever comprehensive assessment of the extinction risk of all native lycopod and fern species to Europe. With 194 species assessed, this assessment highlights that 19.9% of lycopod and fern species are threatened with extinction in Europe. This is mainly due to urban and infrastructure development, human intrusions and disturbance, pollution, and water use and management.

Taxonomic review is provided for taxa of Callitriche L. (Callitrichaceae) occurring in North America. One new species, C. stenoptera Lansdown, is described from Arizona in the United States, and the following names are lectotypified: C. anceps Fernald, C. drummondii Hegelmaier, C. hermaphroditica L. var. bicarpellaris (Fenley ex Jepson) H. Mason, C. longipedunculata Morong, C. marginata Torrey, C. nuttallii Torrey, C. sepulta S. Watson, and C. stenocarpa Hegelmaier.

Based on a recent collection made by the authors, the presence of the endangered Pilularia minuta Durieu in Sicily (Italy) is confirmed. Critical review of relevant literature and herbarium specimens suggests that the only previous report for the island, made in 1887, can, fairly confidently, be considered to be the result of a misidentification. There is an urgent need to protect the wetland at Anguillara (near Calatafimi), where the species was found.

Taxonomic review is provided for Callitriche taxa occurring in central and eastern Asia east of the Urals and in southeastern Asia north of Irian Jaya Barat. Three new species: Callitriche fuscicarpa, C. glareosa, and C. raveniana are described from Nepal, Bhutan, and Taiwan, China, respectively. Two new varieties are also described: Callitriche palustris L. var. megalata from Siberia in Russia and Callitriche palustris L. var. strumosa from western Sumatra in Indonesia. Callitriche nana is newly referred as a synonym of C. japonica Engelmann ex Hegelmaier. Callitriche oryzetorum Petrov is transferred and reduced in rank to a variety of C. palustris L. Callitriche wightiana Wallich in Wight is lectotypified.

The names described by Linnaeus in the genus Callitriche are discussed and most are newly typified. Callitriche palustris L. is recognised, with C. verna L. as a heterotypic synonym, and the current usage of C. hermaphroditica L. is maintained.

Historically there has been confusion over the status and identification of Callitriche species in South Africa. Review of herbarium specimens and fieldwork have enabled confirmation of the presence of C. deflexa as a naturalised species in this country and confirmed that C. compressa and specimens named as C. bolusii are conspecific. Field surveys showed that C. compressa still occurs in the areas from which most historic collections were made with no evidence of a decline, it is widespread but local in Kwa-Zulu Natal and Eastern Cape Provinces and extends into eastern Western Cape Province. However because it is known from only five widely scattered sites, it is classed as Vulnerable under the IUCN Red List. We also typify here the names C. compressa and C. deflexa.

This article presents new records of water-starworts (Callitriche sp. pl.) from the Mediterranean basin, resulting from review of herbarium specimens and field work. Callitriche brutia var. naftolskyi is stated as a new combination and confirmed from Greece (Lesvos and Milos), Israel, Italy (Sardinia and Sicily), Libya, Morocco and Syria; C. lusitanica from Greece (Lesvos), Israel and Italy (Sardinia and Sicily); C. brutia var. brutia has been known from Greece for some time but is confirmed from Lesvos and Milos; C. obtusangula and C. truncata subsp. truncata are both confirmed from Sardinia and Sicily, while the latter is also confirmed from Syria. Callitriche lenisulca and C. stagnalis are confirmed from Sardinia but records of the latter from Lesvos appear to be erroneous; C. truncata subsp. occidentalis is known from Lesvos but records from Sardinia and Sicily appear to be erroneous. Records of C. regis-jubae from Sardinia are probably misidentifications for C. brutia var. naftolskyi. Records of C. brutia var. hamulata from the region are likely to be erroneous. A recent find of the alien C. terrestris in Spain is the first record for that country and the second record for Europe.

The UK government has an obligation to monitor the condition of EUNIS habitat 3260 “Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation”. To assess the potential of the MTR data collection method to provide data for this monitoring, a study was carried out by the Environment Agency on the River Itchen SAC in Hampshire involving data collection in the spring, summer and autumn each year from 2004 to 2008. Data analyses included calculation of trends in MTR scores for each survey data-set, comparison against traditional concepts of conservation value and comparison of data on water-crowfoots. MTR scores were inconsistent and it seems unlikely that that they indicate changes in trophic state. Data were unsuitable for assessment against traditional concepts of conservation value as they do not relate to comparable habitats and specifically exclude habitats outside the channel. The taxonomy of the water-crowfoots, combined with the fact that data do not relate to phytosociological units, means that they cannot be used to demonstrate trends in the abundance or health of these plants. The conclusion was reached that MTR data collection method is not a suitable means of collecting data toward monitoring the condition of EUNIS habitat 3260.