Astragalus centralis: The Tamditau Milkvetch evaluated as Critically Endangered.

Milkvetches, Astragalus spp., are leguminous herbs of or shrubs, predominantly found in arid or semi-arid climates around the Northern Hemisphere. They are a large group of Plants, with 3082 species recognised in 2025, this is largely because many species are highly endemic (i.e. have very limited ranges). Such limited ranges can make species extremely vulnerable to extinction, though to date only 149 species of Astragalus have been formerly assessed to determine their status under the terms of the International Union for Conservation of Nature's Red List of Threatened Species, with 36% of these being determined to be threatened, and one, the Tallante's Milkvetch, Astragalus nitidiflorus, has been found to be extinct in the wild.

Thirty two species of Astragalus have been recorded in Uzbekistan, more than any other genus in the country. Most of these are found within the low mountain ranges of the Kyzylkum Desert, a notable centre of Plant endemism covering parts of Uzbekistan, Kazakhstan, and Turkmenistan. Within this desert a series of low mountain ranges (typically lower than 1000 m) form a western extension of the Central Asian Mountain Belt, creating a range of distinctive micro-habitats. promoting Plant endemism. Of the forty two species of Astragalus known from this region, six are thought to be entirely endemic. 

In a paper published in the journal Orynx on 18 February 2026, Bekhruz Khabibullaev, Khabibullo Shomurodov, and Natalya Beshko of the Institute of Botany of the Academy of Sciences of the Republic of Uzbekistan, and Giuseppe Fenu of the Department of Life and Environmental Sciences at the University of Cagliari, formally assess the conservation status of Astragalus centralis, referred to here as the Tamditau Milkvetch, an endemic species from the Kyzylkum Desert of Uzbekistan. 

The Tamditau Milkvetch is a perennial herbaceous Plant reaching about 15 cm in height, with stems covered in white hairs, paired leaves, and dense inflorescences of yellow flowers. It was formerly thought to be present in the Tamditau, Kuldzhuktau, and Auminzatau mountain ranges within the Kyzylkum Desert. However, a previous study, published in 2016, established that the populations in the Kuldzhuktau and Auminzatau mountains were in fact a separate species, which was described as Astragalus kuldzhuktauense. 

As a result of this, the known occurence of Astragalus centralis shrank to a single population in the Tamditau Mountains, prompting monitoring and censuses of the species in 2016-17, 2018-19, and 2023-24, each time assessing the number of Plants present at the peak of the flowering season.

The Tamditau Milkvetch grows on northern slopes in the Tamditau Mountains, in crevices between large boulders in gravelly and rocky limestone soils. All known members of the species are found within an area of 60 000 m². During the 2016-17 season, about 1000 Plants were recorded, but in 2018-19 this had fallen to about 600 individuals, within an increased proportion of older Plants (80% against 50% in 2016-17. In 2023-24 only 491 Plants were recorded, with 90% of these being mature.

The mountains of the Kyzylkum Desert, Uzbekistan, showing the distribution of Astragalus centralis on the northern slope of the Tamditau (Aktau) mountains. Khabibullaev et al. (2026).

The species appears to be facing a number of immediate threats. Limestone is extracted in the region, and new excavation trenches are both present and increasing in number within the range of the Tamditau Milkvetch. The population is also located close to a settlement which primarily derives its income from livestock herding, with the area where the species grows being used as a year-round pasture. Climate change appears to be making the area more arid, and Insects have been observed to consume more of the species seeds in dryer years. This drying climate is also associated with more frequent and intense spring flash floods, which can destroy younger Plants with less well established root systems. The species is also vulnerable to short-term cold anticyclones, which occur in the area every 5-6 years.

Characteristic habitat of Astragalus centralis, endemic to the Tamditau (Aktau) mountains. Khabibullo Shomurodov in Khabibullaev et al. (2026).

Based upon this, Khabibullaev et al. suggest that the Tamditau Milkvetch is becoming unable to sustain its only population, due to a low and decreasing survival rate for young Plants. For this reason they recommend that the species be classified as Critically Endangered under the terms of the International Union for Conservation of Nature's Red List of Threatened Species. 

The Tamditau Milkvetch in its habitat. Khabibullo Shomurodov in Khabibullaev et al. (2026).

Based upon this, Khabibullaev et al. recommend a series of steps to be taken in order to protect the future of the Tamditau Milkvetch. 

Firstly, the species habitat should be designated a protected area. This would not just protect this species, but also other species found in the area which have been identified as at risk, including the Kyzylkum Giant Fennel, Ferula kyzylkumica, the Aktavi Stickseed, Lappula aktaviensis, The Kyzylkum Peppergrass, Lepidium subcordatum, the Hairy Catchfly, Silene tomentella, and the Aktau Needlegrass, Stipa aktauensis. They further recommend that the Tamditau Mountains should be considered to be a significant national ecosystem, and assessed for potential inclusion on the nternational Union for Conservation of Nature's Red List of Ecosystems.

Detail of the inflorescence of the Tamditau Milkvetch, Astragalus centralis. Khabibullo Shomurodov in Khabibullaev et al. (2026).

Secondly, they recommend that an inventory of pasture resources in the region is carried out, in order to determine the sustainable grazing capacity of the area, and develop a better plan for livestock management.

Thirdly, they suggest a translocation strategy for the species, moving individual Plants to other areas identified as suitable for its survival.

Fourthly, they suggest that a cultivated population be established at the Kyzylkum Desert Experimental Station, and seeds of the species be gathered and placed in an appropriate seed bank.

Finally, they suggest that the species be included on the International Union for Conservation of Nature's Red List of Threatened Species, and an awareness campaign for the species be used to promote its conservation.

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The Holly and the Alphaproteobacterium.

The Family Phyllobacteriaceae comprises a group of 19 genera of Alphaproteobacteria, commonly associated with Plants, with many species associated with nitrogen-fixation, nutrient cycling and bioremediation (converting toxic substances into non-toxic substances), although other species are found free-living in soil or water. Strains belonging to the family Phyllobacteriaceae are usually Gram-stain-negative, rod-shaped, aerobic, non-spore forming and non-motile or motile utilising polar, subpolar or lateral flagella. Many members of the genera Mesorhizobium and Phyllobacterium have Plant-growth-promoting properties, with Mesorhizobium in particular commonly associated with the rhizosphere (root-system and associated biological community) of Legumes, where some species have been shown both to fix nitrogen, which is then utilised by the Plants, and receive carbon compounds from the Plants in return. Members of the genus Aminobacter have also been shown to be capable of fixing nitrogen and in some cases to be associated with the root-nodules of Legumes, although this genus is typically free-living in soil or water, with some species surviving entirely chemolithotropicly, utilising carbon monoxide in the process.

In a paper published in the International Journal of Systematic and Evolutionary Microbiology on 3 November 2025, Sinchan Banerjee of the School of Life Sciences at the University of Warwick, András Táncsics of the Department of Molecular Ecology at the Hungarian University of Agriculture and Life Sciences, Zeqin Wu, Tudor Stafioiu, and Jiacheng Gao, also of the School of Life Sciences at the University of Warwick, Erika Tóth of the Department of Microbiology at Eötvös Loránd University, Erzsébet Baka, also of the Department of Molecular Ecology at the Hungarian University of Agriculture and Life Sciences, and Gary Bending and Hendrik Schäfer, again of the School of Life Sciences at the University of Warwick, describe a new species of Phyllobacterium, derived from the leaves of a Holly tree, with the ability to oxidise carbon monoxide.

Carbon monoxide is a common pollutant, produced by a range of industrial and other Human activities, and deadly to both Human and most Animal life. Notably, it is a significant product of biomass burning, which many countries are looking to as a potential energy source as they try to move away from a dependence on fossil fuels. Carbon monoxide is also produced by a range of natural occurrences, from forest fires to rock weathering, but does not build up in the environment, as it is also removed by a range of biological and non-biological processes. This means that carbon monoxide does not present a global atmosphere-changing threat, in the way that carbon dioxide or methane emissions do, but that it does represent a significant hazard at the local level, and that means of reducing that hazard are of interest to a range of researchers.

The phyllosphere, that part of Plants which is above the ground, presents a novel and often challenging environment for micro-organisms, with fluctuating exposure to heat and ultraviolet radiation, nutrient supplies strictly controlled by the host-Plant, and, frequently, exposure to a range of environmental pollutants. 

Banerjee et al. collected Common Holly, Ilex aquifolium, leaves from Tocil Wood Nature Reserve in Coventry, UK. Leaf-wash preparations were made from these, and stored in vials with the headspace filled with carbon monoxide. Samples where the carbon monoxide level was found to drop were placed on agar plates, and incubated at 25°C for five days, to promote Bacterial growth. 

The resultant colonies were subject to 16S rRNA gene sequence analysis, which established that Banerjee et al. had found a novel Barcterial strain, which they identified as SB112ᵀ. This strain was then subjected to a full genome phylogenomic analysis, establishing that it was a novel species of Phyllobacterium, related to the genus Mesorhizobium. 

Since SB112ᵀ does not appear to fir into any currently designated genus, Banerjee et al. assign it to a new genus, which they name Foliimonas, which is derived from 'folium' meaning 'leaf' and 'monas' meaning 'unit' (a common suffix for Bacterial names), and give it the specific name ilicis, meaning 'of the Holly Tree'.

Phylogenomic tree constructed using Up-to-date Bacterial Core Genes (concatenated alignment of 92 core genes) showing the phylogenetic position of Foliimonas ilicis (SB112ᵀ). For inferring the tree, the FastTree algorithm was used. Bar represents 0.02 substitution per nucleotide position. Banerjee et al. (2025).

Foliimonas ilicis is a Gram- reaction- negative, aerobic, rod-shaped Bacterium, which is motile with a polar flagellum. Cells have an average length of 1.18 μm. The species has an optimum growth range of 20-37°C, with growth stopping completely below 4°C. Foliimonas ilicis can oxidise carbon monoxide, but is unable to reduce nitrous oxides of ferric citrate. It produces esterase (C4), esterase lipase (C8), leucine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase, valine arylamidase, cystine arylamidase and trypsin, but not urase. It could assimilate d-glucose, l-arabinose, d-mannitol, d-mannose, potassium gluconate and malic acid, and metabolise l-arabinose, d-xylose and xylitol.

Transmission electron microscopic photograph showing cell morphology and presence of flagella in Foliimonas ilicis. Scale bar is 1 µm. Banerjee et al. (2025).

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Petalidium saxatile: A new species of Petal-bush from Namibia.

Petal-bushes, Petalidium spp., are woody perinal shrubs in the Family Acanthaceae found in arid sandy or stoney areas of Africa, India, and the Mascarene Islands, although most species are found in areas of Southern Africa with summer rainfall and no frosts. There are currently 35 species recognised from Southern Africa, of which 33 are found in Namibia, 13 in Angola, and six in South Africa. Despite the name 'bush', they are diverse in form, ranging from scrambling herbs to large, robust shrubs. Many species of Petalidium are fast-growing and produce attractive  flowers, leading to some species being cultivated by gardeners.

In a paper published in the journal Phytotaxa on 3 September 2025, Wessel Swanepoel of the H.G.W.J. Schweickerdt Herbarium at the University of Pretoria, Kyle Dexter of the School of GeoSciences at the University of Edinburgh, the Royal Botanic Garden Edinburgh, and the Department of Life Sciences and Systems Biology at the University of Turin, Martino Adamo, also of the Department of Life Sciences and Systems Biology at the University of Turin, Erin Manzitto-Tripp of the Department of Ecology & Evolutionary Biology, & Museum of Natural History at the University of Colorado, and Abraham Van Wyk, also of the H.G.W.J. Schweickerdt Herbarium at the University of Pretoria, and of the South African National Biodiversity Institute, describe a new species of Petalidium from the Kaokoveld Desert of northwestern Namibia.

The new species is described on the basis of four populations of Petalidium in the Kaokoveld discovered by Wessel Swanepoel while carrying out research for a monograph on the genus in Southern Africa. The populations had been observed by him before, and assumed to belong to the species Petalidium canescens, which is also found in the region. However, in May 2018 Swanepoel visited a population near Palmwag while it was in flower, suggesting that it was a different species, something which was later backed up by generic analysis.

The new species is named Petalidium saxatile, where 'saxatile' derives from the Latin 'saxatilis', meaning 'found amongst rocks', from the habitat where it lives. These Plants form a hemispherical woody shrub about 50 cm tall, with bifurcating stems and elongate oval leaves, both covered with white hairs. Flowers are roughly tubular, with four lobes, the lower of which is yellow and the others pinkish brown (unlike the all pink flowers of Petalidium canescens).

Petalidium saxatile, morphology of flowers. (A), (B) Newly opened and faded flowers. Anterior corolla lobe inside (adaxially)  bright yellow and without nectar guides. (C) Flower viewed from above, showing puberulous abaxial surface of posterior corolla lobes. (D) Flowers viewed obliquely from above, all corolla lobes discolorous with the outside (abaxial) surfaces puberulous and notably paler in  colour. The long white trichomes next to the flower on the right do not belong to the plant, but is a wind-blown feathery awn (arrowed) of  a member of the Grass genus Stipagrostis. Wessel Swanepoel in Swanepoel et al. (2025).

Petalidium saxatile is known from only four sites, three in an approximate line from Palmwag southwards to Bergsig, and one on Welbedacht Farm, to the south of Khorixas. It has been found growing among rocks from the Etendeka Group basalt, on arid hillsides and along drainage lines at elevations of 860–1130 m above sealevel, between 70 and 150 km from the sea. Searches of other areas with similar conditions did not reveal any further populations. It is calculated that the area of potential habitation for Petalidium saxatile is 3337 km², but the area of actual habitation is less than 20 km². All of the areas where the species is found are prone to prolonged droughts. As such, Swanepoel et al. recommend that Petalidium saxatile be classified as Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species. 

Known distribution of Petalidium saxatile (black dots). Swanepoel et al. (2025).

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Prunus luxurians: A new species of Cherry from southwestern Ecuador.

The genus Prunus has a worldwide distribution and contains several important food crops (including Cherries, Almonds, and Plums), ornametal species (Blossom Cherries), timber souces (e.g. Black Cherry) and medicinal Plants (e.g. African Cherry). There are thought to be about 450 valid species in the genus, but the situation is complicated with about 1230 species described within the genus, and over 2000 more in other genera that have since been synonymised with it (i.e. genera which have had all their putative members moved into Prunus. 

Historically, it has been thought that the majority of Prunus species are found in the northern temperate belt, with a smaller number of species found at high altitudes in tropical and subtropical zones. However, recent research has discovered that the genus is much more widespread in lowland tropical forests than previously realised, particularly in the Americas, raising the possibility that the genus is more diverse in these regions than in the temperate zone.

In a paper published in the journal PhytoKeys on 4 April 2025, Álvaro Pérez of the Herbario QCA at the Pontificia Universidad Católica del Ecuador, Jorge Andrés Pérez-Zabala of the Herbario Gabriel Gutiérrez Villegas at the Universidad Nacional de Colombia, Katya Romoleroux, also of the Herbario QCA at the Pontificia Universidad Católica del Ecuador, David Espinel-Ortiz, again of the Herbario QCA at the Pontificia Universidad Católica del Ecuador, and of the Bonn Institute of Organismic Biodiversity at the University of Bonn, and Chaquira Romoleroux and Natasha Albán-Vallejo, once again of the Herbario QCA at the Pontificia Universidad Católica del Ecuador, describe a new species of Prunus from southwestern Ecuador.

The new species is described from a small population of trees discovered in a cloud forest remnant in the Sambotambo Birón area of the Jocotoco Foundation-managed Reserve Buenaventura in El Oro Province, on the western flank of the Andes, between 1300 and 1400 m above sealevel. The new species is named Prunus luxurians, in reference to its 'profuse blooming and outstanding beauty', which makes it a conspicuous part of the lower and mid-strata of the forest.

Prunus luxurians: (A) Habit, (B branch with leaves and floriferous shoots, (C) flowers. Álvaro Pérez in Pérez et al. (2025).

Prunus luxurians forms trees up to 11 m high, with grooved dark brown bark with lighter lenticles (raised pores). Leaves are oblong-to-lance-shaped, waxy, and grow on alternating sides of leaf stems, they are 10–13.65 cm long and 3.5–4.65 cm wide. Flowers are white with light green centres, and born on floriferous shoots, which can have 14–27 individual flowers, clusetered together in groups of 3-4.

Only five living trees were found, in a fragment of montane evergreen forest, with high levels of bith diversity and endemism. The remaining forest fragments in this region are considered to be threatened by mining and farming activities, for which reason Pérez et al. recomend that Prunus luxurians be classified as Critically Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species.

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Boswellia hesperia: A new species of Dwarf Frankincense from Socotraa Island.

Frankincenses, Boswellia spp., are trees and small shrubs noted for the aromatic resin they produce, found in East Africa, Arabia, and parts of South Asia. In 1971 Frank Nigel Hepper of Kew Royal Botanic Gardens described a Dwarf Frnakincense, Boswellia nana, from the Yemeni island of Socotra in the Indian Ocean (a noted hotspot for botanical endemism). In 2004, botanists Anthony Miller and Miranda Morris reported a second species of Dwarf Frankincense from Socotra, something which several subsequent studies have also recorded, but which has not, to date, been formally described.

In a paper published in the Nordic Journal of Botany on 20 February 2025, Mats Thulin of the Department of Organismal Biology at Uppsala University, Michael Weber from Bad Berka in Germany, Sami Ali Mohammed Mubarak from Socotra Island, and Alain Rzepecky from São Brás de Alportel in Portugal, formally describe the second species of Socotran Dwarf Frankincense.

The new species is named Boswellia hesperia, where 'hesperia' means 'west', the species having been found exclusively at the western end of the Island of Socotra; this is in contrast to Boswellia nana, which is found exclusively at the eastern end of the island. Boswellia hesperia is an entirely prostrate dwarf species, found growing within holes and crevasses in limestone rock. This habit is also seen in Boswellia nana, although that species sometimes also produces dwarf shrubs up to 2 m high. Boswellia hesperiai also differs from Boswellia nana in its leaves, which are waxy above, but covered in white fur below, whereas those of Boswellia nana are waxy on both sides.

Boswellia hesperia from mountain ridge above Neet, 5–6 km from the coast, Socotra, 18 May 2021. (A) plant filling out crevice in limestone rock, leafless, showing reddish white flowers and fruits, (B) leafless plant with flowers and fruits. Alain Rzepecky in Thulm et al. (2025).

The total area over which Boswellia hesperia is found is about 63 km², however, the distribution of the species is patchy, and it probably is only found over an area of about 20 km². This limited distribution, along with the apparent risk of the species being overgrazed by Goats, leads Thulm et al. to recommend that Boswellia hesperia be classified as Critically Endangered under the terms of the International Union for Conservation of Nature's Red List of Threatened Species.

Boswellia hesperia, seedling flowering after about one and a half year in cultivation. Alain Rzepecky in Thulm et al. (2025).

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