Maarten Christenhusz

Plant Gateway · Research

Heptacodium miconioides, also known as ‘the seven‐son flower’, is illustrated from a plant cultivated at the Royal Botanic Gardens, Kew. Originally from China, it was discovered in the early 20th Century, but was first introduced into western horticulture in the 1980s from plants grown at the Hangzhou Botanical Garden. A detailed description is pro...

The ‘pearl of the forest’, also known as ‘yin shan’ or the ‘giant panda of the plant kingdom’, Cathaya argyrophylla is illustrated here (t. 1051) from a tree cultivated at the Royal Botanic Gardens, Kew. The discovery and phylogenetics of this species are discussed, and its introduction into horticulture is presented. A detailed description is prov...

We present a genome assembly from an individual Scutellaria galericulata (the marsh skullcap; Streptophyta; Magnoliopsida; Lamiales; Lamiaceae). The genome sequence is 328 megabases in span. Most of the assembly is scaffolded into 15 chromosomal pseudomolecules. The mitochondrial and plastid genomes have also been assembled and have lengths of 326....

Giant genomes are rare across the plant kingdom and their study has focused almostexclusively on angiosperms and gymnosperms. The scarce genetic data that are available for ferns,however, indicate differences in their genome organization and a lower dynamism compared toother plant groups. Tmesipteris is a small genus of mainly epiphytic ferns that...

Asteraceae, the daisy family, are one of the most diverse families of angiosperms and are predominant in many ecosystems, including grasslands, deserts, savannas and high-elevation mountains. They are characterized by a peculiar inflorescence, the capitulum, which mimics a flower, but is actually made up of many tightly grouped florets. The capitul...

We present a genome assembly of an Arabidopsis thaliana specimen (thale cress; Streptophyta; Magnoliopsida; Brassicales; Brassicaceae). The genome sequence spans 138 megabases. Most of the assembly (98.76%) is scaffolded into five chromosomal pseudomolecules. The mitochondrial and plastid genomes were also assembled and are 368.8 and 154.5 kilobase...

Background and aims Among the numerous pantropical species of the yam genus, Dioscorea, only a small group occurs in the Mediterranean basin, including two narrow Pyrenean endemics (Borderea clade), and two Mediterranean-wide species (D. communis and D. orientalis, Tamus clade). However, several currently unrecognized species and infraspecific taxa...

Although some authors previously questioned the circumscription of Nicotiana benthamiana, it has never been treated taxonomically as more than a single widespread, variable species. A recent study employing phylogenetic and population genetic analyses has demonstrated that N. benthamiana comprises five species that are geographically and morphologi...

One of the most commonly encountered and frequently cited laboratory organisms worldwide is classified taxonomically as Nicotiana benthamiana (Solanaceae), an accession of which, typically referred to as LAB, is renowned for its unique susceptibility to a wide range of plant viruses and hence capacity to be transformed using a variety of methods. T...

One of the most commonly encountered and frequently cited laboratory organisms worldwide is classified taxonomically as Nicotiana benthamiana (Solanaceae), an accession of which, typically referred to as LAB, is renowned for its unique susceptibility to a wide range of plant viruses and hence capacity to be transformed using a variety of methods. H...

Background and aims: The extent to which genome size and chromosome numbers evolve in concert is little understood, particularly after polyploidy (whole-genome duplication), when a genome returns to a diploid-like condition (diploidisation). We study this phenomenon in 46 species of allotetraploid Nicotiana section Suaveolentes (Solanaceae), which...

The vascular flora of Britain and Ireland is among the most extensively studied in the world, but the current knowledge base is fragmentary, with taxonomic, ecological and genetic information scattered across different resources. Here we present the first comprehensive data repository of native and alien species optimized for fast and easy online a...

For almost 30 years, there have been active discussions about the taxonomic impediment and the challenge this represents to address the current human-induced biodiversity crisis. From the start (Systematics Agenda 2000, 1994), the term ‘taxonomic impediment’ has been ambiguous, designating both the insufficiency and inadequacy of the resources put...

Nicotiana hesperis is illustrated from plants collected near the Billabong Roadhouse in north-western Western Australia, which were cultivated at the Royal Botanic Gardens, Kew. Its taxonomic history, ecology, cytology and cultivation are discussed.

The Australian species Nicotiana walpa is newly described here from plants collected at the Uluru-Kata Tjuta National Park in the Northern Territory, Australia, and illustrated from plants cultivated at the Royal Botanic Gardens, Kew. Its discovery, ecology, cytology and cultivation are discussed.

The new species Nicotiana pila is described here from plants collected in the Little Sandy Desert of Western Australia. Seeds were germinated and plants cultivated at the Royal Botanic Gardens, Kew, which were used for the illustration. Its taxonomic history, ecology, cytology and cultivation are discussed.

Nicotiana murchisonica is described here. It is illustrated from plants collected along the Murchison River and tributaries in Western Australia and cultivated at the Royal Botanic Gardens, Kew. Its discovery, ecology, cytology and cultivation are discussed.

In this volume of Curtis's Botanical Magazine, we increase the number of species recognised in Nicotiana sect. Suaveolentes to 38, up from the 21 recorded in the Flora of Australia published 39 years ago, but we estimate the final number is likely to exceed 60. We examine the reasons why so many unrecognised species exist. Several Australian and Am...

Nicotiana rosulata is illustrated from plants grown from seeds collected near Leonora in the Goldfields region of Western Australia. The plants were cultivated in the quarantine house of the Royal Botanic Gardens, Kew. The taxonomic history, ecology, cytology and cultivation of this species are discussed.

Nicotiana megalosiphon is illustrated from plants cultivated at the Royal Botanic Gardens, Kew, which were grown from seeds collected near the bridge over the Mehi River near Moree, New South Wales, Australia. Its taxonomic history, ecology, cytology, etymology and cultivation are discussed. The two subspecies previously recognised within this taxo...

The Australian species Nicotiana hoskingii from the Planchonella Nature Reserve in New South Wales is newly described and illustrated from plants cultivated at the Royal Botanic Gardens, Kew. Its discovery, ecology, cytology and cultivation are discussed.

Nicotiana monoschizocarpa is illustrated from plants collected along the banks of the Daly River in the Northern Territory (Australia) and cultivated at the Royal Botanic Gardens, Kew. Its taxonomic history, ecology, cytology and cultivation are discussed.

Nicotiana salina is described here and illustrated from plants collected at Weelhamby Lake, a salt lake in Western Australia, and cultivated at the Royal Botanic Gardens, Kew. We discuss its ecology and cultivation.

The new species Nicotiana insecticida, which is remarkable in its insect trapping abilities, is described here. It is illustrated from plants that were grown from seeds collected near the Minilya Roadhouse on the Northwest Coastal Highway in Western Australia, Australia. They were cultivated at the Royal Botanic Gardens, Kew. Its distinguishing fea...

Plants collected in Towarri National Park in New South Wales were cultivated at the Royal Botanic Gardens, Kew. It is illustrated here and described as the new species, Nicotiana notha. Its origin, cytology, taxonomic history, ecology and cultivation are discussed.

Nicotiana truncata is illustrated from plants collected between Coober Pedy and Oodnadatta in South Australia and cultivated at the Royal Botanic Gardens, Kew. Its taxonomic history, ecology, cytology and cultivation are discussed.

Nicotiana exigua is illustrated from plants collected in New South Wales, Australia, at the Narran Lake Nature Reserve and cultivated at the Royal Botanic Gardens, Kew. Its taxonomic history, ecology, cytology and cultivation are discussed.

Nicotiana ingulba is returned to species level here. It is illustrated from plants cultivated at the Royal Botanic Gardens, Kew, which were grown from seeds collected in the Uluru‐Kata Tjuta National Park in the Northern Territory, Australia. Its taxonomic history, ecology, cytology, etymology and cultivation are discussed.

Field studies of the inselberg flora of north-eastern Brazil have resulted in the discovery of much greater morphological diversity of the genus Ameroglossum, than previously envisaged. These enigmatic plants are endemic to isolated rock outcrops, which have long been surrounded by unsuitable habitat. The morphological forms are geographically isol...

Background and aims: Extant plant groups with a long fossil history are key elements in understanding vascular plant evolution. Horsetails (Equisetum, Equisetaceae) have a nearly continuous fossil record dating back to the Carboniferous, but their phylogenetic and biogeographic patterns are still poorly understood. We use here the most extensive p...

To address the polyphyly of Phaius and Calanthe in recent molecular studies, we recommend the merger of these genera along with Cephalantheropsis and Gastrorchis, which are embedded among the first two genera. Some authors have instead proposed to segregate new genera from both Phaius and Calanthe, but this results in generic concepts for which the...

Nicotiana section Suaveolentes is the largest section of Nicotiana and is a monophyletic group of allotetraploid species. Most of the species are endemic to Australia, but three species occur on islands in the South Pacific as far east as French Polynesia and one species is native to Namibia. Here, we present phylogenetic results based on genome sk...

Recent molecular evidence has confirmed that Meiostemon and Quisqualis are embedded in Combretum. While some of the species in the two former genera have already been transferred to Combretum, several combinations are still wanting. New combinations for these species in Combretum are therefore formalised here for taxa of Meiostemon and Quisqualis t...

Tiganophyton karasense, an evergreen dwarf shrub, is described as a new species. A new genus and family are also proposed for it in the order Brassicales. Phylogenetic analysis of DNA sequence data indicate that Tiganophyton is sister to Bataceae/Salvadoraceae, and all three sister to Koeberliniaceae. First realized to be undescribed in 2010, T. ka...

The 14th International Symposium on Tardigrada took place in Copenhagen, Denmark from 30 July to 3 August 2018. Approximately 140 participants, representing 28 countries from five continents attended the meeting, and there were 58 talks and 74 posters of which 20 were selected for the Symposium Proceedings published in this special issue. The studi...

Nicotiana section Suaveolentes is the largest section of Nicotiana and is a monophyletic group of allotetraploid species. Most of the species are endemic to Australia, but three species occur on islands in the South Pacific as far east as French Polynesia and one species is native to Namibia. Here, we present phylogenetic results based on genome sk...

Taxonomy faces some major challenges in the 21st Century (Godfray 2002). The threat to biodiversity comes largely from human overpopulation, but the impact of climate change is unprecedented (Pievani 2014) and increasingly a risk factor for many species. This makes it even more critical to rapidly catalogue our biodiversity to better protect it (Ma...

During field studies of the inselbergs of northeastern Brazil, two potentially new species of were discovered. They share morphological characters with several genera of Linderniaceae (Lamiales) such as Ameroglossum, Cubitanthus and Stemodiopsis, but the morphological differences are such that they do not make a good fit with any of the known gener...

In 1993, a shrub with yellow flowers reminiscent of but obviously distinct from Turnera was found near Mabura Hill in central Guyana, which was recollected in 2000. This paper offers a morphological description including leaf and wood anatomy and pollen morphology in addition to a phylogenetic analysis based on plastid DNA. Thanks to these studies,...

Horsetails (Equisetum, Equisetaceae) are one of the oldest groups of vascular plants with a nearly continuous fossil record dating back to the Carboniferous. Only a few studies have addressed relationships among and within the extant members of this fern genus. We here present the first complete phylogenetic analysis of one or more samples of all e...

Genetic structure in broadly distributed herbs may be shaped by past climate events, leading to distinct genetic lineages, and possibly to different Evolutionary Significant Units (ESUs). We identified the potential glacial refugia, postglacial (re)colonization routes, contact zones and ESUs in the widespread but locally rare Silene nutans to propo...

Repetitive DNA has an important role in angiosperm genomes and is relevant to our understanding of genome size variation, polyploidisation and genome dynamics more broadly. Much recent work has harnessed the power of high-throughput sequencing (HTS) technologies to advance the study of repetitive DNA in flowering plants. Herbarium collections provi...

Nicotiana gossei is the preferred species of Nicotiana used for chewing by native Australians. It was previously a widely traded commodity. We here describe and illustrate this formerly economically important species from plants collected in the Northern Territory of Australia and cultivated at the Royal Botanic Gardens, Kew. Its ecology, tradition...

Nicotiana faucicola is newly described and illustrated from plants collected in the Flinders Ranges of South Australia and cultivated at the Royal Botanic Gardens, Kew. Its discovery, ecology, cytology and cultivation are discussed.

Nicotiana maritima is illustrated. Its ecology, cytology and horticultural use are discussed.

Nicotiana umbratica is described and illustrated from plants collected from the Pilbara Region of Western Australia and cultivated at the Royal Botanic Gardens, Kew. Its ecology, etymology, cytology and cultivation are discussed.

This special issue highlights some of the wonderful species of native Australian tobacco (Nicotiana sect. Suaveolentes). We here present twelve species of this genus, four of which are new to science. Many Nicotiana species have a high ornamental value, and we hope that particularly the rarer Australian species will find a way into horticulture to...

Nicotiana yandinga is newly described here and illustrated from plants collected in the Gawler Ranges in South Australia and cultivated at the Royal Botanic Gardens, Kew. Its discovery, ecology, cytology and cultivation are discussed.

Nicotiana occidentalis subsp. obliqua is a highly glandular and scented tobacco widespread in Australia. It is illustrated from plants collected along the Gascoyne River and cultivated at the Royal Botanic Gardens, Kew. Its ecology, cytology and horticultural use are discussed.

Nicotiana benthamiana is described and illustrated from plants collected in northwestern Western Australia and cultivated at the Royal Botanic Gardens, Kew. It is widely used as a laboratory plant in plant virus studies, and we also discuss its cytology, cultivation and natural ecology.

Nicotiana excelsior is a species restricted to central Australia. It is illustrated here from plants grown at the Royal Botanic Gardens, Kew, from seeds collected at Kata‐Tjuta‐Uluru National Park in the Northern Territory. It is a very attractive species and makes an excellent horticultural subject. Its ecology, etymology, traditional use and cult...

Nicotiana burbidgeae is a spectacular species that is a narrow endemic from the northern part of South Australia. It is illustrated from plants collected near Dalhousie Springs (Witjira National Park) and cultivated at the Royal Botanic Gardens, Kew. Its ecology, cytology and horticultural potential are discussed.

Nicotiana karijini is newly described here and illustrated from plants collected in the Pilbara region in Western Australia and cultivated at the Royal Botanic Gardens, Kew. Its discovery, ecology, etymology and cultivation are discussed.

Nicotiana gascoynica is newly described and illustrated from plants collected in the Gascoyne region of Western Australia and cultivated at the Royal Botanic Gardens, Kew. Its discovery, ecology, cytology and cultivation are discussed.

Nicotiana stenocarpa has long been considered a synonym of N. rosulata subsp. rosulata, to which it is only distantly related. It grows in the Goldfields area of Western Australia, often sympatrically with N. rosulata subsp. rosulata. The plant illustrated here was collected on the Leonora–Agnew Road in Western Australia and cultivated at the Royal...

Background. Agave sisalana is a cultigen from Mexico. In 1833 it was brought to Florida by Henry Perrine as an experimental crop. From there it was introduced to tropical Africa and Asia in the late 19th Century, where it became established as a fiber crop. Paradoxically, in the Yucatan it meanwhile evanesced from its already scanty presence. Becau...

With a long fossil history (Taylor, Taylor & Krings 2009), Marattiaceae are among the earliest lineages of vascular land plants and are an important link to understanding land plant evolution. The family currently has a pantropical distribution, but was more widely distributed in the past. In the neotropics the family is represented by the genera M...

Changing concepts of genera have historically character- ized vascular plant taxonomy, leading to fluctuations in the size and number of genera. In ferns, the number of families and genera recognised in formal classifications have had particu- larly inconsistent circumscriptions (reviewed in Christenhusz & Chase, 2014). Unlike angiosperms, in which...

Introduction to the new plant taxonomic serial.

This article provides a visual overview of the relationships of all angiosperm families (following APG IV). The poster lists important characters for major grades and clades and these are illustrated with flower images of 269 plant families. It is presented to provide a useful educational tool. The scientific names and photo accreditation of each i...

Few plants are so cryptic as the underground orchids, Rhizanthella Rogers (1928: 1), of Australia. Unlike the species on the eastern seaboard of Australia, the Western Australian species spend their entire life cycle, including flowering, below the soil surface (only rarely with the tips of the bracts showing), making them unique among orchids and...

Two new sympatric species of Caladenia from relatively inaccessible, high lateritic plateaux in a high rainfall area in southwestern Western Australia are described here as new to science. The species occur in a restricted area, c 100 km southeast of Perth, south of Dwellingup and northeast of Waroona. The two species co-occur and are associated wi...

Plants of the World is the first book to systematically explore every vascular plant family on earth--more than four hundred and fifty of them--organized in a modern phylogenetic order. Detailed entries for each family include descriptions, distribution, evolutionary relationships, and fascinating information on economic uses of plants and etymolog...

At 50-fold the size of the human genome (3 Gb), the staggeringly huge genome of 147.3 Gb recently discovered in the fern Tmesipteris obliqua is comparable in size to those of the other plant and animal record-holders (i.e., Paris japonica, a flowering plant with a genome size of 148.8 Gb, and Protopterus aethiopicus, a lungfish with a genome of 130...

This study focuses on tribe Gilliesieae (Amaryllidaceae, Allioideae), which stand out because of their karyotype diversity, constituting a textbook example of Robertsonian translocations (RTs), in which chromosomes fuse or break at the centromere. Polyploidy (i.e. whole genome duplication, WGD) is also common in the tribe, hence making Gilliesieae...

Autumn flowering daffodils have been recorded in taxonomic history for at least 500 years. First descriptions were often merely based on hearsay, as they were often not studied alive. Consequently, many errors in interpretation of these names have occurred and taxonomic confusion, errors in identification and misapplication of names have led to an...

We report the discovery of the largest fern genome in Tmesipteris obliqua (1C = 150.61 pg), a species belonging to the whisk-fern family, Psilotaceae. Its genome size estimated by flow cytometry is comparable with the largest genome so far reported for any eukaryote, in the monocot Paris japonica (Melanthiaceae; 1C = 152.23 pg). The addition of thi...

During a study of Marattiaceae for the Flora Argentina project (www.floraargentina.edu.ar), we noticed that there is an earlier name at species rank for this neotropical fern from southern Brazil and northeastern Argentina, widely and commonly known as Eupodium kaufussii. The name Marattia raddiana Schott was published four years before Hooker publ...

Recent studies showed that a group of Hypertelis species was neither related to the type of that genus or to other members of Molluginaceae. As a result, these species were segregated as a new genus in its own family, Kewaceae. The St Helenan endemic Kewa acida (Hook.) Christenh. is illustrated here and its relationships, status, cultivation and co...

With a history dating back to the sixteenth century, modern botanic gardens have had an important role in plant conservation, most notably since the second half of the twentieth century. The formation of Botanic Gardens Conservation International in the 1980s and the development of the Global Strategy for Plant Conservation have led to many botanic...

Ranunculaceae are a nearly cosmopolitan plant family with the highest diversity in northern temperate regions and with relatively few representatives in the tropics. As a result of their position among the early diverging eudicots and their horticultural value, the family is of great phylogenetic and taxonomic interest. Despite this, many genera re...