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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Dyckia semperflorens: A new species of Bromeliad from the cold region of Rio Grande do Sul, southern Brazil.

Bromeliads are herbaceous Monocotyledons native to the Americas (with a single species known from West Africa) and related to the Sedges and Grasses. They have a distinctive rosette shape, with blade-like leaves spiraling out from a central point. In some cases the centre of this rosette forms a water reservoir held in place by tightly overlapping leaf-bases, which can contain entire miniature ecosystems. Many Bromeliads are epiphytes, living on the branches of trees, particularly in rainforests, but others live on the ground and many are found in deserts.

The genus Dyckia contains 188 recognised species of Bromeliads, making it one of the most specious genera within the group. The majority of these are found in arid areas of Argentina, Bolivia, Paraguay, Uruguay, and Brazil, with about two thirds of all species being found in Brazil. Species of Dyckia tend to have spiny leaves and a succulent form, and often grow on thin soils or directly on rock. They also tend to be highly endemic, with most species having a limited geographical range, and several species known only from a single location.

In a paper published in the Nordic Journal of Botany on 17 October 2025, Henrique Mallmann Büneker and Jorge Ernesto de Araujo Mariath of the Laboratório de Anatomia Vegetal and Programa de Pós-graduação em Botânica at the Universidade Federal do Rio Grande do Sul, describe a new species of Dyckia from an escarpment beside the Rio dos Touros in the municipality if Bom Jesus in Rio Grande do Sul State, Brazil.

The new species is named Dyckia semperflorens, where 'semperflorens', means 'continuously flowering'; when the species was first observed in 2017 a live specimen was collected and brought to the Planeta Bromélia nursery in Porto Alegre, where it has remained in bloom ever since. Specimens of Dyckia semperflorens reach 65-96 cm in height, and have a rosette diameter of 38-65 cm. Leaves are 47-107 cm in length, with the inner leaves being semi-erect, while the outer ones are more relaxed, all have an elongate triangular shape with a waxy surface and sparse spines on the edges. Flowers are born on an erect or semi-erect peduncle, 20-36 cm in length. Flowers are tubular and greenish or reddish, flowers on the base of the peduncle are larger than those towards the tip.

Dyckia semperflorens.  (A) Habitat, (B) clumping habit, (C) flowering plant habit, (D) rosette, (E) detail of the inflorescence. Henrique Mallmann Büneker in Büneker & Mariath (2025).

Dyckia semperflorens is known from a single location, on a rocky escarpment along the banks of the Touros River, 1054 m above sealevel, in the municipality of Bom Jesus, Rio Grande do Sul State, in southern Brazil. The local environment is dominated by grassland, with patches of  Araucaria forest. The climate here is temperate, with frost and snowfall in the winter. 

The only known population of Dyckia semperflorens grows in an area currently under pressure from cattle grazing and frequent anthropogenic fires, which are used for grassland management in the region. However, there are other similar areas in the region which could potentially support the species, and which have not been explored yet, so Büneker and Mariath refrain from assigning a conservation status to the species at this time.

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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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Didymoglossum radiatum: A new species of creeping Fern from Thailand.

The genus Didymoglossum comprises about 30 species of small, generally tropical Ferns growing as epiphytes (i.e. on other Plants) or epiliths (on rocks). Roughly half of the described species come from the Old World, with eight species from tropical Asia. Five species of Didymoglossum are known from India, five from China, one from Vietnam, four from the Solomon Islands, and six from Malesia (Malaysia, Brunei, the Philippines, and western Indonesia). These Ferns, and possibly other, undescribed species, are likely to also be found in the nations between these documented areas, though as yet few, if any, studies have been carried out in these countries.

In a paper published in the journal PhytoKeys on 6 August 2025, Siwakorn Chokrassameehirun of the Department of Horticulture at Kasetsart University, Ekaphan Kraichak of the Department of Botany and Biodiversity Center at Kasetsart University, and Tassanai Jaruwattanaphan, also of the Department of Horticulture and Biodiversity Center at Kasetsart University, present a study of the genus Didymoglossum in which they describe a new species, as well as documenting other species in the country for the first time.

The new species is described from specimens collected in Hala–Bala Wildlife Sanctuary in Waeng District in the far south of Peninsula Thailand, close to the border with Malaysia. The species is named Didymoglossum radiatum, in reference to the false veinlets on the fronds of the Fern, which form a radiating pattern. 

Didymoglossum radiatum. (A) Habit; (B) Raised sori of fertile Plants; (C) Adaxial surface of sterile fronds; (D) Abaxial surface of sterile fronds; (E) False veinlet construction; (F) Sori. Siwakorn Chokrassameehirun in Chokrassameehirun et al. (2025).

Didymoglossum radiatum can be epiphytic or epilithic in nature, with a long, creeping rhizome 0.2-0.3 mm in diameter firmly anchored to the surface over which it grows by numerous dark brown hairs. It produces plate-like fronds 1.0-1.5 mm in diameter, with dense brown hairs around the rims. Each frond typically bears a single sori (spore-producing body).

Illustration of Didymoglossum radiatum. (A) Fertile frond; (B) Sterile fronds; (C) False veinlet construction; (D)–(E) Sori with tubular involucres; (D) Sori with filiform receptacle; (E) Sori borne at the notch of the frond. Siwakorn Chokrassameehirun in Chokrassameehirun et al. (2025).

Chokrassameehirun et al. also record the presence of two species of Didymoglossum in Thailand for the first time. 

The first of these is Didymoglossum henzaianum, a species which grows on rocks close to streams, which was first described from Myanmar in 2014, and which has subsequently been reported in India, Vietnam, and Peninsula Malaysia. Chokrassameehirun et al. found specimens of this species in Phu Ruea District in Loei Province, in the north of the Country.

Didymoglossum henzaianum. (A) Habit; (B) Fertile plants; (C) False veinlets on lamina segment; (D) Sori with obconic–tubular involucres. Siwakorn Chokrassameehirun in Chokrassameehirun et al. (2025).

The second new report is of Didymoglossum mindorense, a species described in the Philippines in 2006, and subsequently reported from Borneo, New Guinea, the Solomon Islands, and Queensland. Didymoglossum mindorense is found at low elevations, and typically close to streams. It is usually found growing around the bases of trees, but will sometimes colonise rocks. Chokrassameehirun et al. reporr specimens of this species in Hala–Bala Wildlife Sanctuary and the area around it.

Didymoglossum mindorense. (A) Habit; (B) Fertile fronds; (C) Lobe of sterile frond; (D) Fertile frond. Siwakorn Chokrassameehirun in Chokrassameehirun 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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