Phylogenetic placement of the monotypic Baolia (Amaranthaceae s.l.) based on morphological and molecular evidence.

BACKGROUND: Baolia H.W.Kung & G.L.Chu is a monotypic genus only known in Diebu County, Gansu Province, China. Its systematic position is contradictory, and its morphoanatomical characters deviate from all other Chenopodiaceae. Recent study has regarded Baolia as a sister group to Corispermoideae. We therefore sequenced and compared the chloroplast genomes of this species, and resolved its phylogenetic position based on both chloroplast genomes and marker sequences. RESULTS: We sequenced 18 chloroplast genomes of 16 samples from two populations of Baolia bracteata and two Corispermum species. These genomes of Baolia ranged in size from 152,499 to 152,508 bp. Simple sequence repeats (SSRs) were primarily located in the LSC region of Baolia chloroplast genomes, and most of them consisted of single nucleotide A/T repeat sequences. Notably, there were differences in the types and numbers of SSRs between the two populations of B. bracteata. Our phylogenetic analysis, based on both complete chloroplast genomes from 33 species and a combination of three markers (ITS, rbcL, and matK) from 91 species, revealed that Baolia and Corispermoideae (Agriophyllum, Anthochlamys, and Corispermum) form a well-supported clade and sister to Acroglochin. According to our molecular dating results, a major divergence event between Acroglochin, Baolia, and Corispermeae occurred during the Middle Eocene, approximately 44.49 mya. Ancestral state reconstruction analysis showed that Baolia exhibited symplesiomorphies with those found in core Corispermoideae characteristics including pericarp and seed coat. CONCLUSIONS: Comparing the chloroplast genomes of B. bracteata with those of eleven typical Chenopodioideae and Corispermoideae species, we observed a high overall similarity and a one notable noteworthy case of inversion of approximately 3,100 bp. of DNA segments only in two Atriplex and four Chenopodium species. We suggest that Corispermoideae should be considered in a broader sense, it includes Corispermeae (core Corispermoideae: Agriophyllum, Anthochlamys, and Corispermum), as well as two new monotypic tribes, Acroglochineae (Acroglochin) and Baolieae (Baolia).

Medullary bundles in Caryophyllales: form, function, and evolution.

The occurrence of conducting vascular tissue in the pith (CVTP) of tracheophytes is noteworthy. Medullary bundles, one of the remarkable examples of CVTP, evolved multiple times across angiosperms, notably in the Caryophyllales. Yet, information on the occurrence of medullary bundles is fragmented, hampering our understanding of their structure-function relationships, and evolutionary implications. Using three plastid molecular markers (matK, rbcL, and rps16 intron), a phylogeny is constructed for 561 species of Caryophyllales, and anatomical data are assembled for 856 species across 40 families to investigate the diversity of medullary bundles, their function, evolution, and diversification dynamics. Additionally, correlated evolution between medullary bundles and successive cambia was tested. Medullary bundles are ancestrally absent in Caryophyllales and evolved in core and noncore families. They are structurally diverse (e.g. number, arrangement, and types of bundles) and functionally active throughout the plant's lifespan, providing increased hydraulic conductivity, especially in herbaceous plants. Acquisition of medullary bundles does not explain diversification rate heterogeneity but is correlated to a higher diversification rate. Disparate developmental pathways were found leading to rampant convergent evolution of CVTP in Caryophyllales. These findings indicate the diversification of medullary bundles and vascular tissues as another central theme for functional and comparative molecular studies in Caryophyllales.

Taxonomic inventory and distributions of Chenopodiaceae (Amaranthaceae s.l.) in Orenburg Region, Russia.

Background: Orenburg Region is located in the South Urals, mostly in the steppe zone and is characterised by various landscapes suitable for many Chenopodiaceae. The species of Chenopodiaceae are present in all major plant communities (saline vegetation, steppes, on limestone, chalk and sand, and as degraded or ruderal communities). In the steppe zone, many native subshrubby species (Atriplexcana, Caroxylonlaricinum, Suaedaphysophora) playing a crucial role in semi-deserts (known as southern steppes in the recent Russian literature) located southwards of Orenburg Region are locally found, and several annuals (Salicorniaperennans, Suaeda spp.) are most common dominants in plant communities. Some typical semi-desert species (Kalidiumfoliatum, Bassiahyssopifolia, Sodafoliosa, Spirobassiahirsuta) are found in the easternmost part of the region. New information: We compiled a checklist of Chenopodiaceae in Orenburg Region, with two new records (Chenopodiumvirgatum, Corispermumlaxiflorum), based on our critical revision, comprehensive inventory of herbarium specimens and documented observations and field research. In total, we report 76 species in the Region, which is the third-highest number of the Chenopodiaceae species compared with other administrative territories of European Russia, North Caucasus and West Siberia. Alien and native taxa are distinguished. Zonal patterns of species distributions are confirmed. A preliminary conservation status is proposed for each native species. Three species are recommended for exclusion from the Red Data Book of Orenburg Region: Petrosimoniatriandra (because of its extensive distribution), Kalidiumfoliatum and Anabasissalsa (because of the lack of actual threat to their populations). Arthrophytumlehmannianum and Salsolarosacea are considered threatened (Vulnerable) because of their restricted occurrence and population size and because their localities are under anthropogenic pressure. Atriplexhortensis, Atriplexrosea, Chenopodiumacuminatum, C.karoi, C.praetericola, C.vulvaria, Climacopteraaffinis, C.crassa, Halimocnemiskarelinii, Salsolapaulsenii and Xylosalsolaarbuscula are excluded from the checklist, based on various reasons as discussed in the paper. Point distribution maps are provided for each species. Agriophyllumpungens (Vahl) Link is accepted as the correct authorship instead of "M.Bieb. ex C.A.Mey."

Evolution of seed characters and of dispersal modes in Aizoaceae.

The family Aizoaceae includes ~1880 species and is one of the more diverse groups within Caryophyllales, particularly in arid areas in the western part of southern Africa. Most species are dwarf succulent-leaf shrubs. In response to the harsh climatic conditions prevalent where they occur, many representatives have evolved special reproductive adaptations. These include hygrochastic capsules (mostly found in Mesembryanthemoideae and Ruschioideae), burr-like indehiscent and one-seeded, winged diaspores, and fast germination of seeds after rain. We focused on anatomical features, evolutionary trends, and the ecological significance of various morpho-anatomical structures found in the seeds. The seeds of 132 species from 61 genera were studied, and 18 diagnostic characters were discovered. All studied characters were compared with those of other families from core Caryophyllales. The seed notch and embryo shape were added to the list of characteristics distinguishing major clades within the family. In addition, the presence of longitudinal ridges and a keel on the seed are additional characters of Aizooideae and combined Ruschioideae-Apatesieae, respectively. Puzzle-like borders of testa cells are a common trait in Ruschioideae and Mesembryanthemoideae. Most taxa in Aizoaceae have a thin seed coat, which is the ancestral state within the family. This may facilitate fast germination. We observed several shifts to a medium-thick or thick seed coat in members of Ruschioideae and Acrosanthoideae. These inhabit fire-prone environments (in vegetation types known as fynbos and renosterveld), where the thickened seed coat may protect against damage by fire. Multi-seeded fruits are the ancestral state within Aizoaceae, with several shifts to one-(two-)seeded xerochastic fruits. The latter are dispersed via autochory, zoochory, or anemochory. This trait has evolved mainly in less succulent subfamilies Acrosanthoideae, Aizooideae, and Sesuvioideae. In highly succulent subfamilies Ruschioideae and Mesembryanthemoideae, fruits are almost exclusively multi-seeded and hygrochastic with ombrohydrochoric dispersal. A reduction in the number of seeds within a dispersal unit is rare. Within Apatesieae and Ruschieae, there are also a few unusual genera whose fruits fall apart into one- to two-seeded mericarps (that are mainly dispersed by wind).

A new species of Atriplex (Amaranthaceae) from the Indian subcontinent.

A new subshrubby C4-species from the lowlands and foothills of India, Pakistan and SE Afghanistan, Atriplexpseudotatarica, is described and illustrated. Previously, it was incorrectly identified as A.crassifolia auct. non C.A.Mey. belonging to a distant C3-group of the genus. A phylogenetic analysis based on nrITS and nrETS revealed its position as sister to A.schugnanica (sect. Obionopsis). Both species share aphyllous inflorescence and smooth bract-like cover, but differ in life form, leaves, seed colour, and geographical distribution. We revised native Indian Atriplex species and excluded some of them from the flora of the country. An improved checklist of the native Atriplex species in India with their corrected synonymy and nomenclature is given, and a new diagnostic key is provided.

A new classification of C4- Atriplex species in Russia, with the first alien record of Atriplexflabellum (Chenopodiaceae, Amaranthaceae) from North Siberia.

For a long time, the systematics of Atriplex was based solely on morphological characters and leaf anatomy. The latest worldwide phylogenetic study of Atriplex significantly improved our knowledge about the relationships within the genus, but a new classification has not been put forward thus far. Here we re-evaluate the taxonomy of C4-species of Atriplex that are native to Russia. Seven species are classified into two sections, A.sect.Obione (incl. A.sect.Sclerocalymma, syn. nov.) (A.altaica, A.centralasiatica, A.rosea, A.sibirica, and A.sphaeromorpha), and A.sect.Obionopsis (incl. A.sect.Psammophila, syn. nov.) (A.fominii and A.tatarica). Although the majority of Eurasian C4-species have similar morphology, leafy inflorescence is a typical character for A.sect.Obione. The members of A.sect.Obionopsis are characterised mostly by aphyllous inflorescences, but some species (A.laciniata, A.pratovii, and A.tornabenei) have leafy inflorescences. Geographically, almost all members of A.sect.Obione are confined to Central Asia, although A.rosea is a typical Mediterranean element and A.argentea occurs in North America. The representatives of A.sect.Obionopsis are distributed mostly in the Mediterranean and the Irano-Turanian floristic region. The alien status of A.rosea, A.sibirica and A.tatarica is discussed. Atriplexflabellum, a desert species from the Irano-Turanian region, is reported for the first time from Russia (Yamalo-Nenets Autonomous District, North Siberia) as a casual alien. This species occupies a phylogenetic position distant from both aforementioned sections. An identification key to all C4-species of the genus growing in Russia is given, and a sectional checklist with updated nomenclature and revised synonymy is provided.

Akhania, a new genus for Salsoladaghestanica, Caroxyloncanescens and C.carpathum (Salsoloideae, Chenopodiaceae, Amaranthaceae).

Genus Salsola s.l. was recently split into several genera of different phylogenetic placements within Salsoloideae, but both taxonomic and phylogenetic relationships of some parts of the former broadly defined Salsola still need to be clarified. A remarkable example is Salsolacanescens nom. illegit. ≡ Salsolaboissieri, a taxon with tricky taxonomic history that was only recently transferred to the genus Caroxylon (tribe Caroxyleae). Salsoladaghestanica, a narrow endemic of Central Dagestan (Russian Federation), was not even included in previous molecular studies of Salsoloideae and therefore still lacks an appropriate estimation of its relationships. Molecular phylogeny constructed here using nuclear and plastid DNA sequence data clearly placed Salsoladaghestanica and Caroxyloncarpathum as sister taxa and the clade S.daghestanica, Caroxyloncanescens (Salsolaboissieri), C.carpathum (Salsolacarpatha) as a sister of the monophyletic Caroxylon. All three species are distinct from Caroxylon from a morphological standpoint. In conclusion, a new genus, Akhania, was established for these taxa. The detailed distribution of Akhaniadaghestanica is presented for the first time.

Biogeography and Systematics of the Genus Axyris (Amaranthaceae s.l.).

Axyris is a small genus of six species with a disjunct geographic range. Five species are present in Siberia, Central Asia, the Himalayas, and Tibet, whereas Axyris caucasica has been registered in the Central Caucasus only. Axyris species diversity is the highest in the Altai Mountains (four spp.), followed by the Tian Shan and Pamir Mountains (three spp.), and the Himalayas and Tibet (two spp.). Axyris sphaerosperma, sometimes considered endemic to Southern Siberia, in fact has a disjunct range: it is present in the lowlands of Eastern Siberia and in the Altai, Tian Shan, and Pamir Mountains. It has also been found in Mongolia and China for the first time. An updated detailed distribution of Axyris in Siberia is presented on the basis of thorough herbarium revisions. One nuclear and three plastid markers were selected for phylogenetic analysis. Divergence times were estimated using a time-calibrated Bayesian approach. Axyris shows two major clades: an Axyris amaranthoides clade and a clade including the remaining species. The latter clade consists of two subclades (A. sphaerosperma/A. caucasica and A. mira/A. prostrata + A. hybrida). The crown age for Axyris dates back to the Early Pliocene (~5.11 mya, the Zanclean). The ancestral range of Axyris covers Southern Siberia, Mongolia, NW China, and the Tian Shan/Pamir Mountains, with extensions toward Eastern Siberia, the Himalayas/Tibet, and the Caucasus. Fruit and seed characteristics of Axyris are discussed with reference to the present phylogenetic results. Closely related A. sphaerosperma and A. caucasica have the thickest seed coat among all Chenopodiaceae, and these traits have probably evolved as adaptations to extremely low winter temperatures. This reproductive peculiarity may explain the disjunct range of A. sphaerosperma, which is restricted to harsh climatic conditions.

The significance of ion-exchange properties of plant root cell walls for nutrient and water uptake by plants.

This review examines the key aspects of ion exchange and diffusion in plant root cell walls and the implications of these processes for the uptake of mineral nutrients and water under both normal and adverse environmental conditions. The data available to date shows that the ion-exchange properties of plant root cell walls are influenced by the plant age and growth conditions, and also vary between species. The cell wall volume and its ability to swell, which regulate the hydraulic conductivity of the cell wall, are determined by the pH and ionic strength of the external solution. It is concluded that the analysis of physico-chemical properties of plant cell wall is an important step in the understanding of the complex processes of water and nutrient uptake.

Evolutionary relationships, biogeography and morphological characters of Glinus (Molluginaceae), with special emphasis on the genus composition in Sub-Saharan Africa.

Glinus is a small genus of Molluginaceae with 8-10 species mostly distributed in the tropics of the World. Its composition and evolutionary relationships were poorly studied. A new molecular phylogeny constructed here using nuclear (ITS) and chloroplast (rbcL, trnK-matK) markers confirmed the monophyly of the genus. Based on ITS analysis, the following well-supported lineages are present within Glinus: the G. bainesii lineage is recovered as sister to the remainder of the genus followed by G. oppositifolius. Three other clades are: G. hirtus with G. orygioides; G. radiatus and G. lotoides; the latter is represented by a sample from North America, and G. zambesiacus as sister to G. setiflorus + G. lotoides + G. dictamnoides. On the plastid gene tree, G. bainesii + G. oppositifolius form a sister clade to all other Glinus species. The next clade is formed by G. hirtus and G. orygioides followed by G. radiatus plus an American sample of G. lotoides. The next branch comprises G. setiflorus as sister to G. zambesiacus + G. lotoides + G. dictamnoides. Glinus seems to have originated from Africa around the Late Eocene or Early Miocene, with further radiations to Australia and the Americas during the Late Miocene or Late Pliocene. Compared with the previous limited character set used for the diagnostics, we have found ten new morphological and carpological traits distinguishing Glinus members. In both trees based on nuclear and plastid datasets, the major phylogenetic clades cannot be characterized by the peculiar morphological characters. Many shared character states leading to their contrasting pattern in the multivariate analysis model are interpreted as a high homoplasy in the phylogenetically distant species. We paid special attention to the composition of the genus in Sub-Saharan Africa, a region with the greatest species diversity. Our results provide new insight into the taxonomy of Glinus in this region. Glinus lotoides var. virens accepted in many previous works is a synonym of G. dictamnoides that is closely related to G. lotoides based on molecular analysis and morphological characters. The status of the American populations of G. lotoides needs further investigation due to different characters of the specimens from the Old and the New World. Many specimens previously identified as G. lotoides var. virens and as the intermediates G. lotoides × G. oppositifolius belong to G. zambesiacus sp. nov. and G. hirtus comb. nov. (≡ Mollugo hirta); the latter species is resurrected from synonymy after 200 years of unacceptance. In some African treatments, G. hirtus was known under the invalidly published name G. dahomensis. Glinus zambesiacus is distributed in the southern and eastern parts of tropical Africa, and G. hirtus previously assumed to be endemic to West Africa is indeed a species with a wide distribution across the tropical part of the continent. Glinus microphyllus previously accepted as endemic to West Tropical Africa together with other new synonyms (G. oppositifolius var. lanatus, G. herniarioides, Wycliffea rotundifolia) is considered here as G. oppositifolius var. keenaniicomb. nov. (≡ Mollugo hirta var. keenanii), a variety found across the entire distribution of G. oppositifolius (Australia, Asia, and Africa). The presence of the American G. radiatus in Africa is not confirmed, and all records of this species belong to G. hirtus. The lectotypes of some names (G. dictamnoides, G. herniarioides, Mollugo hirta, M. setiflora, Pharnaceum pentagynum, Wycliffea) as well as a neotype of G. trianthemoides are designated. A new key to the identification of all Glinus species in Sub-Saharan Africa is provided. A checklist is given of all accepted species in this region (G. bainesii, G. hirtus, G. lotoides, G. oppositifolius s.l., G. setiflorus, and G. zambesiacus) with their nomenclature, morphological description and geographical distribution.

An integrative taxonomic approach reveals a new species of Eranthis (Ranunculaceae) in North Asia.

A new endemic species, Eranthis tanhoensis sp. nov., is described from the Republic of Buryatia and Irkutsk Province, Russia. It belongs to Eranthis section Shibateranthis and is morphologically similar to E. sibirica and E. stellata. An integrative taxonomic approach, based on cytogenetical, molecular and biochemical analyses, along with morphological data, was used to delimit this new species.

The role of the cell walls in Ni binding by plant roots.

The role of the cell wall in short-term Ni uptake at different solution Ni levels was investigated in mung bean (Vigna radiata (L.) R. Wilczek) and wheat (Triticum aestivum L., cv. Inna). Both Ni-binding capacity of the CWs and roots are lower for wheat than for mung bean at all Ni levels in the solution. For both plants amounts of Ni associated with roots and root cell walls increased with Ni concentration. The contribution of CWs to Ni absorption by roots depends on Ni level in the medium and plant species. The Ni accumulated in CWs could account for total Ni content of roots (except for wheat in highest Ni treatment). Besides, mung bean plants employ the strategy of reducing Ni accumulation in the root CWs during exposure to excess but not toxic solution Ni level. According to the results, predominant Ni binding in the apoplast of mung bean and wheat roots is observed at both high and low external Ni, which suggests that apoplastic pathway is the main means of Ni transport in the root cortex of these species.

Taxonomic revision of Chenopodiaceae in Himalaya and Tibet.

The composition of many Chenopodiaceae genera in different parts of Himalaya and Tibet has been insufficiently known or contradictory. A revision of the family in Himalaya including Bhutan, Nepal, parts of India (Himachal Pradesh, Jammu and Kashmir, Sikkim and Uttarakhand) and Tibet (Xizang, China) is presented for the first time. Altogether, 57 species from 20 genera are reported, including three species new to science (Agriophyllumtibeticum, Salsolaaustrotibetica and Salsolahartmannii). Atriplexcentralasiatica, Corispermumdutreuilii and Salsolamonoptera are identified as new records for India and Chenopodiumpamiricum is recorded in China for the first time. Dysphaniaambrosioides and Sympegmaregelii are recorded for Xizang. The generic and species keys, species distributions (including maps) and taxonomic notes are provided. We indicate for the first time that the presence of short yellow hairs is the remarkable morphological characteristic of the genus Grubovia. Evident heterocarpy and heterospermy is found in Dysphania for the first time (Dysphaniatibetica). Agriophyllumpungens, Atriplexcrassifolia, Atriplexlaciniata, Atriplexsagittata, Axyrisamaranthoides, Axyrishybrida, Bassiaindica, Corispermumkorovinii, Dysphaniaschraderiana (=Chenopodiumfoetidum auct.), Halocharisviolacea and Suaedamicrosperma are excluded from the species list. Neobotrydiumcorniculatum is synonymised with Dysphaniakitiae, Neobotrydiumlongii with Dysphaniahimalaica and Neobotrydiumornithopodum seems to be conspecific with Dysphanianepalensis. Corispermumladakhianum is a new synonym of Corispermumtibeticum. Amaranthusdiandrus is added to the synonyms of Acroglochinpersicarioides, and Bassiafiedleri, previously considered as conspecific with Gruboviadasyphylla, is added to the synonymy of Bassiascoparia. Lectotypes of Anabasisglomerata (≡Halogetonglomeratus), Halogetontibeticus (=Halogetonglomeratus), Amaranthusdiandrus (=Acroglochinpersicarioides), Chenopodiumtibeticum (≡Dysphaniatibetica), Corispermumdutreuilii, Corispermumfalcatum, Corispermumlhasaense, Corispermumpamiricumvar.pilocarpum (=Corispermumgelidum, syn. nov.), Corispermumtibeticum, Kochiaindica(≡Bassiaindica), Kochiaodontoptera (≡Bassiaodontoptera) and Salsolamonoptera are selected. Out of 53 native elements, 42 are restricted in their distribution to Himalaya and Tibet at altitudes 2000-4500 m above sea level. The greatest taxonomic diversity of the Chenopodiaceae is represented in Jammu and Kashmir (India) and Xizang (China) with a continuous decrease in the number of species southwards.

Evolutionary relationships and taxonomy of Microtea (Microteaceae), a basal lineage in the core Caryophyllales.

The basal position of the small American genus Microtea within the core Caryophyllales was suggested only recently in accordance with molecular phylogeny. However, the specific relationships within the genus were not traced. The results of our phylogenetic analysis based on the matK chloroplast gene suggest the monophyly of Microtea, and Ancistrocarpus and other related genera should be included in it. Microtea is divided into two major sister clades: clade A consisting of M.glochidiata, M.maypurensis and M.tenuifolia, and clade B comprising M.debilis, M.sulcicaulis, M.scabrida, M.celosioides, and M.papillosa. The nrDNA dataset (ITS), although containing only a limited number of accessions, shows the same species number in clade A, and the remaining species studied (M.debilis, M.scabrida and M.celosioides) form clade B. Subgeneric status is assigned to clades A and B corresponding with the names Microteasubgen.Ancistrocarpus subgen. nov. and Microteasubgen.Microtea, respectively. The diagnostic characters at the subgeneric level are as follows: length of pedicels, number of flowers at each node, number of stamens and styles. A multivariate analysis of 13 distinguishing morphological characters supports the results of phylogenetic analysis. All species have similar pericarp and seed ultrasculpture and anatomy, and they share the reticulate pericarp surface (independent of presence or absence of finger-shaped outgrowths on its surface) and rugose or slightly alveolate seed ultrasculpture. On the basis of morphological characters, we accept 10 Microtea species. A checklist includes a new diagnostic key, morphological descriptions and distribution patterns of each species. Galeniacelosioides is the oldest legitimate name available for the plants previously known as Microteapaniculata, for which the combination Microteacelosioides is validated here. The neotypes of Galeniacelosioides and Microteasprengelii were designated from the collections of Prinz Wied at BR. The name M.foliosa is discussed and finally synonymized with M.scabrida. The lectotypes of Ancistrocarpusmaypurensis (≡Microteamaypurensis), Microteadebilisvar.ovata (=M.debilis), M.glochidiata, M.maypurensisvar.angustifolia (=M.tenuifolia), M.glochidiataf.lanceolata (=M.maypurensis), M.longebracteata (=M.celosioides), M.paniculatavar.latifolia (=M.scabrida), M.portoricensis, M.scabrida, M.sulcicaulis, and Potamophilaparviflora (=M.maypurensis) are designated. Microteasulcicaulis is reported for the first time as native to Bolivia, and M.maypurensis is reported from Indonesia (Java), where it is found as an alien plant with an unclear invasion status.

Diagnostics, taxonomy, nomenclature and distribution of perennial Sesuvium (Aizoaceae) in Africa.

The taxonomy of perennial Sesuvium species in Africa has been poorly investigated until now. Previously five perennial species of Sesuvium were recognised in Africa (S. congense, S. crithmoides, S. mesembryanthemoides, S. portulacastrum, and S. sesuvioides). Based on the differing number of stamens, S. ayresii is accepted here as being distinct from S. portulacastrum. Field observations in Angola also led the authors to conclude that S. crystallinum and S. mesembryanthemoides are conspecific with S. crithmoides. A new subspecies, Sesuvium portulacastrum subsp. persoonii, is described from West Africa (Cape Verde, Gambia, Guinea-Bissau, Mauritania, Senegal). The molecular phylogeny indicates the position of S. portulacastrum subsp. persoonii within the "American lineage" as a part of the Sesuvium portulacastrum complex which needs further studies. A diagnostic key and taxonomic notes are provided for the six perennial species of Sesuvium found in Africa and recognised by the authors (S. ayresii, S. congense, S. crithmoides, S. portulacastrum subsp. portulacastrum, S. portulacastrum subsp. persoonii, S. verrucosum and the facultatively short-lived S. sesuvioides). The distribution of S. crithmoides, previously considered to be endemic to Angola, is now confirmed for the seashores of Republic of Congo and DR Congo. The American species S. verrucosum is reported for the first time for Africa (the Macaronesian islands: Cape Verde and the Canaries). It is locally naturalised in Gran Canaria, being a potentially invasive species. These findings as well as new records of S. verrucosum from Asia and the Pacific Islands confirm its proneness to transcontinental introduction. Lectotypes of S. brevifolium, S. crithmoides, S. crystallinum and S. mesembryanthemoides are selected. The seed micromorphology and anatomy of the perennial African species is studied. Compared to the seeds of some annual African Sesuvium investigated earlier, those of perennial species are smooth or slightly alveolate. The aril is one-layered and parenchymatous in all species and usually tightly covers the seed. The aril detachments from the seed coat that form a white stripe near the cotyledon area easily distinguish S. verrucosum from other species under study.

Taxonomic revision and distribution of herbaceous Paramollugo (Molluginaceae) in the Eastern Hemisphere.

The genus Paramollugo with the type species Paramollugo nudicaulis (≡Mollugo nudicaulis) has recently been described after molecular investigations. Here we report two new endemic Malagasy species: Paramollugo simulans and Paramollugo elliotii, and transfer a forgotten New Caledonian endemic Mollugo digyna to Paramollugo (Paramollugo digyna). Consequently, the number of Paramollugo species in the Eastern Hemisphere is increased from three to six. Almost all genus representatives (except Paramollugo nudicaulis, which has a wide distribution in Southern Asia, Arabia and tropical Africa) are endemic to Madagascar, Somalia, or New Caledonia. Since the type of seed coat ornamentation is crucial for species delimitation, a diagnostic key with new taxonomically significant carpological characters and other new traits is provided for all the herbaceous Paramollugo. The distribution patterns of Paramollugo nudicaulis s.str., Paramollugo simulans and Paramollugo elliotii are presented.

Contribution of apoplast to short-term copper uptake by wheat and mung bean roots.

In this study we addressed the controversial issue of contribution of cell walls (CWs) to Cu binding in plant roots. We compared short-term Cu uptake at different solution Cu levels by mung bean (Vigna radiata (L.) R. Wilczek) and wheat (Triticum aestivum L., cv. Inna) and by root CWs isolated from either Cu-treated or non-treated plants. Twenty four hours of plant exposure to Cu affected Cu-binding capacity of mung bean root CWs but not wheat CWs. Amounts of Cu associated with CWs and roots increased with Cu concentration. The Cu accumulated in CWs could account for total Cu content of roots (except for wheat in highest Cu treatment). Pectin content of the CWs and their Cu-sorption capacity were positively correlated. The accumulation of Cu in root CWs is a principal response of wheat and mung bean plants to excess Cu, limiting symplastic Cu uptake in roots in short-term treatment. The contribution of CWs to Cu absorption by plant roots depends on Cu level in the medium and plant species.