Volatile emissions from materials used in conservation have the potential to damage cultural assets when in contact with them or when accumulated in enclosed spaces. To evaluate material’s emissions and their potential interaction with museum collections, the Oddy test remains widely used by cultural institutions as an accelerated corrosion test. However, it presents several limitations related to its duration, the limited reactivity of its metal substrate and the degree of subjectivity involved in interpreting results.,In this study, trap-enrichment Solid-Phase Microextraction Gas-Chromatography Mass-Spectrometry (trap-enrichment SPME-GC-MS) was applied to analyze the volatile emission of nine Fused Deposition Modeling (FDM) polylactic acid (PLA) materials previously tested with the Oddy test. The main aim was to gain a deeper understanding of the potential long-term volatiles emitted by FDM materials and their relationship with the corrosion products formed during the Oddy test, analyzed by Raman spectroscopy.,Prior to the analysis, the method was optimized and validated using three FDM materials. A sample mass of 1 g was found to be suitable for characterizing the emission profile while maintaining reproducible results. The operating temperature during the sampling played a significant role by increasing the number of released compounds while not exceeding 80 ºC.,Finally, volatile emissions were correlated with the Oddy test results. In addition, Raman spectroscopy measurements were taken on the corrosion products formed on the Oddy test coupons. Results show that headspace analysis provides a more detailed chemical insight than the Oddy test. The optimized headspace method presented in this study can be applied to other materials to obtain information about their composition and emission. However, volatile studies demand a higher level of expertise for proper data interpretation.

The endemic flora of Mediterranean islands faces a dramatic extinction risk, as exemplified by Silene migjornensis (Caryophyllaceae), an annual species restricted to a single location along c. 4 km of coastal dunes on the island of Mallorca. The aim of this study was: (1) to reconstruct the evolutionary history of S. migjornensis and relatives based on the nuclear ribosomal Internal Transcribed Spacer (ITS) region; and (2) to estimate levels of genomic diversity and relationships among 48 individuals from the three subpopulations based on a high-throughput sequencing technique, genotyping-by-sequencing (GBS). The ITS phylogeny indicated that S. migjornensis is closely related to S. colorata, S. sericea, S. arabica, and S. reverchonii. The population genomic analysis revealed low genetic diversity in all three subpopulations and supported two weakly differentiated genetic units: one comprising two large subpopulations and the other corresponding to a small subpopulation. Based on the occurrence of a single population, narrow endemicity, habitat fragility and very low genetic diversity, we highlight the extinction risk faced by S. migjornensis. Additionally, we suggest specific management strategies including genetic reinforcement (using the three subpopulations), ex situ conservation, and environmental monitoring and supervision to ensure its long-term survival and viability.

Volatile emissions from conservation materials can pose risks to cultural heritage objects, especially in enclosed environments. The Oddy test, though widely used, is limited by long testing times, low chemical specificity, and subjective interpretation. This study applies trap-enrichment solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) to analyze volatile emissions from nine fused deposition modeling (FDM) polylactic acid materials previously assessed by the Oddy test. The aim was to chemically characterize emitted compounds and relate them to observed corrosion, supported by Raman spectroscopy of corrosion products. Method optimization using three representative materials identified 1 g as an optimal sample mass for sensitivity and reproducibility. Sampling temperature was critical: higher temperatures enhanced analyte release but were kept below 80 degrees C to prevent thermal degradation. Results show that SPME-GC-MS offers significantly greater chemical resolution than the Oddy test, enabling identification of specific volatiles associated with corrosion. Correlation with Raman data strengthened links between emissions and corrosion products.

In the conservation of Cultural Heritage, bronze disease — an aggressive and destructive form of copper alloy corrosion induced by chlorides — remains a major challenge, as it is often detected only at an advanced stage, when intervention becomes difficult. This study employed potentiostatic Electrochemical Impedance Spectroscopy (EIS) measurements on two sets of bronze samples to assess the feasibility of early detection of bronze disease (which is invisible to the naked eye and undetectable with most portable instruments) and to evaluate a novel coating based on upcycled polystyrene (PS-MA). Since bronze artworks often require in situ characterization, and given the delicate nature of their surfaces, minimizing contact between the bronze and electrolyte during EIS measurements is essential. To simulate outdoor conditions, coated bronze mockups were analyzed using a gel polymer electrolyte (G-PE). EIS analysis yielded valuable insights into the electrochemical behavior of the system and assessed the protective efficacy of the synthesized coatings. Additionally, Spectral-Domain Optical Coherence Tomography (SD-OCT) was employed to examine coating adhesion and thickness on the bronze surface.

Research on sustainable protective coatings for metallic heritage presents significant challenges due to the inherent complexity of corrosion processes in bronze, patina, and outdoor environmental systems. Additionally, the absence of standardised testing and evaluation methods hampers the comparability of results and the establishment of best practices. New sustainable coatings based on Paraloid (R) B44, with a light stabiliser and a corrosion inhibitor, have been optimised for a low toxicity profile. The tested formulations include Tinuvin (R) 312 as light stabiliser and 5-mercapto-1-pheniltetrazole (MPT) or 2-amino-5-ethyl-1,3,4-thiadiazol-(AEDTA) as corrosion inhibitors. Their physicochemical properties have been determined through multi-analytical characterisation and monitoring of changes during artificial solar light ageing. Nonetheless, the effectiveness of a coating is also greatly affected by the application method and the chemical, physical and morphological properties of the underlying surface. In this work, the role of Paraloid (R) concentration in a two-layer brush application method is addressed on quaternary bronze with a Verde Messina foundry patina. The influence of resin concentration on the resulting layer is analysed. Patinated bronze mock-ups were non-destructively characterised before and after treatment by Electrochemical Impedance Spectroscopy (EIS) to assess corrosion resistance, colour by colourimetry to evaluate visual appearance, and by Eddy Current to measure the patina and coating thickness. After artificial thermo-hygrometric ageing of the coated mock-ups, Fourier Transform Infrared Spectroscopy in external reflection mode (ER-FTIR) and colourimetry were used to assess the treatment stability with respect to molecular composition and colour changes. Principal Component Analysis (PCA) of ER-FTIR spectra allowed highlighting differences in coatings over the ageing process. Results showed that all tested treatments increased the corrosion resistance of Verde Messina patinated bronze; double-layer coatings with a more diluted first layer were found to be the preferred treatment, providing comparable performance while using a smaller amount of Paraloid (R). (c) 2026 The Authors. Published by Elsevier Masson SAS. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

A good storage system is crucial for the preservation of a museum's artefacts. The choice of these systems depends largely on the nature of the collection, in particular the materials and size of the artefacts, but also other external constraints such as the financial resources of the museum. Proper environmental monitoring and understanding how it impacts the conservation of materials are essential for implementing effective preventive conservation measures. This study examines the storage environment and the suitability of the storage systems of the National Museum of Science and Technology (MUNCYT) in Madrid (Spain) from the conservation point of view. For this purpose, metallic coupons were placed inside and outside a closed mobile shelving system and wrapped and unwrapped in a tissue used for large artefacts in an open pallet racking area. The corrosion of the coupons was evaluated in terms of corrosion rate by gravimetry and electrolytic cathodic reduction according to ISO 11844:2020, colour changes were analysed with a spectrophotometer, and the corrosion products formed were characterised by XRD in grazing incidence mode. The results enabled a comparison of the corrosiveness in different areas, identification of possible sources of aggressive pollutants, and demonstrated the effectiveness of storing artefacts inside shelving and tissue wrapping in reducing metal degradation (especially silver) of the artefacts in the MUNCYT collection.

In the recent years, Additive Manufacturing (AM) technologies & horbar;popularly known as 3D printing & horbar; have been introduced in different areas of daily life and nowadays a wide variety of polymeric printing materials are available. The term AM comprises a huge range of fabrication processes mainly characterized by the method employed during the transformation of the raw materials. Amongst them, Extrusion-based technologies, and specifically Fused Deposition Modelling (FDM) have become very popular, affordable and widespread for many applications. Three-dimensional printing has demonstrated a relevant potential to contribute to the conservation and restoration of cultural heritage, as well as to artistic production. Some applications of AM in the conservation landscape are the design of display systems, the creation of storage structures and the reconstruction of missing parts. Thus, the interaction of new AM materials introduced in the proximity of cultural assets in a closed space could represent a risk of damage when gaseous pollutants are emitted from the printing material. In this context, a literature review was conducted, and the Oddy test was performed to assess a selection of 9 FDM PLA materials, evaluating their long-term behaviour in terms of Volatile Organic Compounds (VOCs) emissions and their suitability for use in heritage conservation and artistic production. Polylactic acid (PLA) is a widespread polymer used for FDM due to its cost and the rise of the social awareness concerning the relevance of using waste-recycling and biodegradable materials. This assay was performed both before and after subjecting the 3D printed samples to accelerated ageing in a Xenon-Arc chamber during 1080 h of exposure with 60 W/m(2) irradiance through a window glass filter, temperature of 60 degrees C and 10 % relative humidity. After the Oddy test, the FDM materials were evaluated, and their recommendation of use was classified based on the corrosion observed on the metallic coupons. Simultaneously, crystalline efflorescences emerged from the 3D printed samples exposed to the Oddy Test, motivating their observation through optical microscopy. Additionally, for the chemical characterization, inorganic fillers of the PLA filaments were analysed with Energy Dispersive X-ray spectroscope attached to a Scanning Electron Microscope (SEM-EDX). The results allowed the classification of PLA filaments for their permanent or temporary use in an environment with cultural assets and reject those that released harmful pollutants. It is remarkable the effect of the additives and fillers when comparing the results in terms of corrosive VOC emissions of different composite PLA materials. The lower corrosion of the metals was promoted by PLA containing CaCO3 fillers, while other PLA combinations were completely discarded. Nonetheless, crystalline efflorescences emerged from 3D printed samples containing mineral fillers. It is suggested that the combination of continuous high temperature and saturated relative humidity is a probable cause of these transformations. Thus, the potential for these minerals to grow at ambient conditions over an extended period and migrate to a cultural asset that is in direct contact with the 3D printed material should be also considered for their recommendation or rejection. (c) 2025 The Authors. Published by Elsevier Masson SAS. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Silver tarnishing in museum environments depends on multiple, interacting factors that are not often studied in situ. With the aim of addressing the problem in real-world scenarios, this study presents a one-year assessment at the National Archaeological Museum of Spain, in Madrid, a museum that houses a significant collection of silver objects. Pure Ag coupons were placed in four display cases—two designs with different airtightness—and in an adjacent gallery. Tarnishing was quantified by colorimetry, gravimetry, and galvanostatic reduction, and analyzed in relation to environmental parameters (T/RH) and gaseous pollutants (H2S, SO2, HF, HCl, formic and acetic acids), measured with passive samplers. Coupons showed different degrees of tarnish, with annual corrosion rates ranging from IC1 (very low) to IC2 (low), without a straightforward relation to hydrogen sulfide concentrations. Electrochemical profiles and XPS on representative coupons identified Ag2S as the dominant product, with AgCl and minor Ag2SO4 in the coupons exposed outside the airtight cases, indicating different contributions inside and outside the cases. Findings highlight that sulfide concentration is not the sole driver; case airtightness, internal materials, cleaning products used on adjacent areas, and, possibly, other aspects influence silver tarnishing.

Assessing the suitability of display case construction materials is crucial to prevent museum object damage. This study evaluates three mass spectrometry (MS) approaches, HS-SPME-trap-enrichment-GC-MS, DTD-GC-MS, and DART-HRMS, for analysing volatile organic compound (VOC) emissions from exhibition and storage materials. Results were compared with the Oddy test, which assesses material corrosivity. HS-SPME-trap-enrichment improved sensitivity for detecting low-abundance corrosive volatiles, such as acetic acid, while DTD offered broader chemical profiling. Correlations between acetic acid emissions and lead corrosion in Oddy tests suggest GC-MS-based methods can predict material corrosivity. DART-HRMS effectively confirms specific additives, while GC-MS shows potential to serve as a screening tool for material classification. Though MS techniques provide faster analysis and detailed chemical insights than the Oddy test, they require a higher level of knowledge for data interpretation. With further refinement, MS approaches could complement to traditional corrosion testing, offering an efficient screening tool for evaluating materials used in conservation.

This article looks at the conservation of historic aircraft from the Second World War, testing different coatings to protect their aluminium alloy structures from corrosion. Five different protective protection systems, including ParaloidTM B72, wax, DinitrolTM , Multi Matt Clear LesonalTM and carboxylates, were evaluated by being applied to artefacts from WWII aircraft wrecks, in particular a wing fragment from a Supermarine Spitfire and a propeller blade from a P38 Lightning, which presented different surface conditions. The protected objects were exposed to real-life conditions (uncontrolled indoor environment). Advanced analytical techniques such as electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FTIR), optical coherence tomography (OCT) and scanning electron microscopy (SEM) were used to characterize the evolution and effectiveness of the protection systems. The results showed different degrees of effectiveness for different coatings. DinitrolTM and LesonalTM demonstrated the best protective properties, forming thin but effective layers that enhance corrosion resistance. Carboxylates, on the other hand, proved ineffective, while ParaloidTM B72 and wax were not very effective and unsuitable for objects with original paint residues. (c) 2025 Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

This study explores the effectiveness of different coatings in preserving aluminum alloy aircraft wrecks. In cultural heritage conservation, coatings must not only protect artefacts under corrosive exhibition conditions but also maintain their visual integrity and be reversible for future treatments. Three coatings were selected and tested: ParaloidTM, commonly used in conservation; DinitrolTM, an industrial product for aluminum protection; and Cutin, a novel coating derived from recycled tomato peels. Each coating was assessed based on its protective ability, aesthetic impact, and reversibility. ParaloidTM, while aesthetically pleasing and easily reversible, offers limited protection, especially outdoors. DinitrolTM demonstrated superior protective qualities, with high impedance values indicating strong corrosion resistance. However, its reversibility properties are limited. Cutin showed promise as a protective coating. It is also reversible with ethanol. However, its current formulation affects the surface appearance due to residual tomato pigments.

Since the introduction of the Oddy test in 1973, many museums and cultural institutions have put the method in use, developing their own versions and protocols. Currently the 3-in-1 version, temperature at 60 ºC and 2 g of tested material are set as common practice; however, other variables of the test are not standardized. The purpose of this study is to examine current versions of the Oddy test, to identify differences in the results derived from variations in the procedures, and ultimately raising awareness within the conservation community to work together towards a standardized protocol. In this article, we review the available information on the methodological differences in Oddy test protocols published in the literature related to glassware cleaning, coupon preparation, reaction vessel setup and rating of materials. Based on the review, and to highlight the many variables that could affect the results of the test, seven European cultural institutions working under the H2020 IPERION HS project performed a comparative 3-in-1 Oddy test by blindly evaluating the same ten materials. Each institution used its own test methodology but some guidelines were advised: (1) Detergents as a cleaning procedure for glassware, (2) P600 sandpaper or micromesh pad close to 1500 to prepare metal coupons and (3) 1:100 as water–air ratio. Despite this, differences between institutions’ results were still observed. Some of them are due to the differences in the coupons preparation, either in the sanding pattern or in the edge area. In order to separate the contribution of the experimental setup and the subjectivity of the evaluation in the discrepancies, coupons from all institutions have been rated by a single team of judges with experience in the Oddy Test. Results show that differences in the evaluation criteria play a relevant role in the discrepancies of the results, especially for institutions with less experience in the test. These results highlight the need to further standardize the methodology and criteria for visual assessment. Nevertheless, the Oddy test has been found to be reliable for the identification of materials that produce emissions hazardous for the conservation of cultural assets.

Abstract Astydamia latifolia is the only species of the genus Astydamia, which forms an early‐diverging lineage of Apiaceae, subfamily Apioideae. This species is subendemic to the Canary Islands and one of the most representative species of the coastal environments of this archipelago. Astydamia displays diplochory, that is, diaspores with two long‐distance dispersal (LDD) syndromes. In particular, A. latifolia has both anemochorous and thalassochorous fruit traits (corky and winged mericarps). Although we expect this species to have a high dispersal capacity, there is no genetic study addressing it. The divergence time of this species from its sister taxon is also unknown. In this study, we aimed (i) to unveil the phylogenetic relationships and divergence times of A. latifolia; (ii) to reconstruct its phylogeographic structure across the Canary Islands; and (iii) to estimate the number of inter‐island colonization events. To these ends, we first sequenced the internal transcribed spacer (ITS) region for A. latifolia, reconstructed the phylogenetic relationships of Astydamia and Apiaceae relatives and estimated divergence times. Then, two plastid DNA regions (psaI‐aacD and psbK‐trnS) were sequenced for 158 individuals (from 36 Canarian population and one NW African population) to reconstruct a haplotype network. The recently developed method Phylogeographic Analysis of Island Colonization Events (PAICE) was used to estimate the number of inter‐island colonization events. Results show that A. latifolia is a phylogenetically isolated lineage that diverged from the most closely related genus (Molopospermum) in the Eocene–Miocene. It displays a low plastid DNA diversity (only four haplotypes detected), which is accompanied by a high degree of haplotype sharing between islands and highly linear rarefaction curves of colonization obtained in PAICE. These findings suggest a high colonization ability for this species, most likely related to the availability of two LDD syndromes.

The study and development of protective coatings for metallic heritage is a topic of continuous research, with the main objective of ensuring the protection of the object for as long as possible. The limitations imposed by conservation and restoration criteria, together with the diversity of factors involved, make metal protection an unresolved subject. In addition to the nature of the protective coating, different fac-tors can influence its effectiveness, which may mean that one type of protection performs well in a cer-tain environment or on one type of metal and not on another. Therefore, the main objective of this work is to provide a comprehensive review of the coatings used in the conservation of metallic heritage from the last decades to the present day. Studies carried out on coatings of the different families according to their nature/composition (waxes, acrylic resins, nitrocellulose lacquers, fluoropolymers, carboxylates, organosilanes compounds and other coatings) have been reviewed, considering the substrate, application, weathering and examination.& COPY; 2023 The Author(s). Published by Elsevier Masson SAS on behalf of Consiglio Nazionale delle Ricerche (CNR). This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

This paper presents results on the protective properties of different coatings over metals representative of those found in scientific–technical heritage collections. An examination of several objects in the collection of the Spanish National Museum of Science and Technology have allowed the identification of brass and steel as the most representative metals, and the existence of coatings (mainly shellac and acrylic resins) applied for aesthetic and/or conservation purposes. Based on these findings, brass and steel coupons coated with Paraloid B-44, B-48, B-67, B-72, Incralac, Cosmolloid H80, B-72 + H80 double layer and shellac have been studied to carry out a first screening in order to select the most promising candidates and determine the most appropriate methodology and key factors for the study. Coatings have been aged up to 336 h using cycles of UV light and water condensation. The change in the aspect of the coupons has been assessed via visual examination, optical microscopy and colorimetric measurements, with B-44 and Incralac showing the least change. EIS has been used for a quantitative evaluation of the protective properties and FTIR to measure chemical changes experienced by some coatings, such as B-48 and B-67. These evaluations allowed us to follow, understand and compare the behaviour of the different coatings and substrates after artificial ageing.

Background and Aims The Canary Islands have strong floristic affinities with the Mediterranean Basin. One of the most characteristic and diverse vegetation belts of the archipelago is the thermophilous woodland (between 200 and 900 m.a.s.l.). This thermophilous plant community consists of many non-endemic species shared with the Mediterranean Floristic Region together with Canarian endemic species. Consequently, phytogeographic studies have historically proposed the hypothesis of an origin of the Canarian thermophilous species following the establishment of the summer-dry mediterranean climate in the Mediterranean Basin around 2.8 million years ago. Methods Time-calibrated phylogenies for 39 plant groups including Canarian thermophilous species were primarily analysed to infer colonization times. In particular, we used 26 previously published phylogenies together with 13 new time-calibrated phylogenies (including newly generated plastid and nuclear DNA sequence data) to assess whether the time interval between stem and crown ages of Canarian thermophilous lineages postdates 2.8 Ma. For lineages postdating this time threshold, we additionally conducted ancestral area reconstructions to infer the potential source area for colonization. Key Results A total of 43 Canarian thermophilous lineages were identified from 39 plant groups. Both mediterranean (16) and pre-mediterranean (9) plant lineages were found. However, we failed to determine the temporal origin for 18 lineages because a stem-crown time interval overlaps with the 2.8-Ma threshold. The spatial origin of thermophilous lineages was also heterogeneous, including ancestral areas from the Mediterranean Basin (nine) and other regions (six). Conclusions Our findings reveal an unexpectedly heterogeneous origin of the Canarian thermophilous species in terms of colonization times and mainland source areas. A substantial proportion of the lineages arrived in the Canaries before the summer-dry climate was established in the Mediterranean Basin. The complex temporal and geographic origin of Canarian thermophilous species challenges the view of the Canary Islands (and Madeira) as a subregion within the Mediterranean Floristic Region.

Materials such as wood, textiles, or plastics that are part of the exhibition system in museums are known to emit pollutants such as organic acids. Scientific and technical objects that include these materials in their composition can themselves be a potential source of emissions, which, together with inappropriate humidity and temperature conditions, can lead to corrosion of the metallic parts. In this work, we have studied the corrosivity of different locations in two venues of the Spanish National Museum of Science and Technology (MUNCYT). Coupons of the most representative metals from the collection were placed in different showcases and rooms for 9 months. The corrosion of the coupons has been evaluated in terms of the rate of mass gain, colour changes and characterisation of the corrosion products. The results were correlated to the relative humidity and concentration of gaseous pollutants to determine which metals are most susceptible to corrosion. The results show that metal artefacts exposed in showcases have a higher risk of corrosion than those exposed directly in the room, and that some pollutants are emitted by the artefacts. The corrosivity of the museum environment is low for copper, brass, and aluminium in most locations; however, some placements present a higher aggressivity for steel and lead, due to the high humidity and the presence of organic acids.

The development of new alternatives for the protection of metallic heritage aims to improve the performance of the coatings used in recent decades. For this purpose, the performance of three novel or poorly explored coatings in this field of study has been evaluated: Owatrol Oil, TiO 2 -modified Paraloid B-72 and a hybrid of poly(2-ethyl-2-oxazoline), PEOX and poly(4-hydroxy styrene), PHS as a self-healing coating. These have been compared with coatings widely used in conservation such as: Paraloid B-72, Incralac and microcrystalline wax C80. The coatings were evaluated after accelerated ageing in terms of aesthetic changes (visual observation under stereomicroscope and colour measurements), protective ability (electrochemical impedance spectroscopy) and chemical stability (FTIR). After 500 h of exposure to Xenon-arc lamp, it was observed how the addition of TiO 2 to Paraloid B-72 partially reduces photo-oxidation of the polymer, but at the same time harms the protective ability due to the appearance of defects. The self-healing coating is quite stable and can also regenerates superficial scratches of about 100 µm if subjected to 90% RH. On the other side, Owatrol demonstrated a very poor performance. These advantages and disadvantages in their use have been compared with those of B-72, Incralac and C80 microcrystalline wax, identifying in which cases their application for protection on scientific-technical artefacts may be feasible.

Euphorbia canariensis is an iconic endemic species of the Canary Islands and one of the most characteristic species of lowland xerophytic communities known, in Spanish, as ‘cardonal-tabaibal’. This species is widely distributed in the archipelago, which contrasts with the theoretically low dispersal abilities suggested by its unspecialized diasporas. Furthermore, the phylogenetic relationships of this species are unclear, although it is thought to be related to the Indian E. epiphylloides and not to other cactus-like Euphorbia of the Canary Islands ( E. handiensis ) and Africa. Here we aimed to reconstruct the evolutionary history of E. canariensis at two levels: (i) a phylogenetic approach aimed at unravelling relationships of this species and large-scale biogeographic patterns, and (ii) a phylogeographic approach focused on the history of colonization between islands of the Canarian archipelago in relation to habitat availability for this species through time. Based on previous phylogenetic studies of Euphorbia , we sequenced the ITS region for E. canariensis and several potentially related species to build a phylogenetic framework. We also sequenced two cpDNA regions for 92 individuals from 29 populations of E. canariensis representing its distribution range. We estimated the number of inter-island colonization events using PAICE, a recently developed method that includes a sampling effort correction. Additionally, we used species distribution modelling (SDM) to project current habitat availability for E. canariensis to past periods. Phylogenetic results supported the Canarian E. canariensis as closely related to the Southeast Asian E. epiphylloides and E. sessiliflora . In the Canarian archipelago, E. canariensis displayed a surprising west-to-east colonization pattern. The estimated number of inter-island colonization events was c. 20 – 50, and SDM suggested an increase in habitat availability in recent times. In summary, in this study we confirmed an extreme biogeographic disjunction between Macaronesia and Southeast Asia, described only for a small number of plant species, and estimated relatively low dispersal capabilities for E. canariensis , with a west-to-east colonization pattern in the Canary Islands. Highlights The Canarian Euphorbia canariensis is sister to Southeast Asian species. This lineage shows one of the widest disjunctions affecting Macaronesian plants. The lack of intermediate relatives could be the result of extinction events. E. canariensis displays low colonization ability in the Canarian archipelago.