From a phylogenetic perspective, Euphorbia balsamifera, found in the arid regions of northwestern Africa and the Canary Islands, is closely related to Euphorbia adenensis, which originates from the Eritrea-Arabia region. These two species share a common ancestor that likely emerged several million years ago.
Molecular data suggest that the divergence between E. balsamifera and E. adenensis occurred during the Pliocene, a period spanning approximately 5.3 to 2.6 million years ago. This era coincides with a major episode of climate aridification in the subtropical regions of the Old World, leading to the fragmentation of forest habitats in favor of more open and arid landscapes. These new environmental conditions likely facilitated a rapid adaptive radiation of the ancestral group, meaning the emergence of several lineages specialized for arid habitats.
In this context, E. balsamifera is thought to have colonized the Canary Islands from northwestern Africa. This colonization may be explained by the "surfing syngameon" mechanism—an evolutionary hypothesis in which a flexible gene pool (or syngameon) "surfs" waves of dispersal into new territories while maintaining sufficient genetic diversity to allow rapid adaptation to novel environments.
Computer models using convolutional neural networks (a form of artificial intelligence) suggest that E. balsamifera first settled on the eastern islands (Lanzarote, Fuerteventura), before migrating westward (Tenerife, Gran Canaria).
Contrary to what one might assume, the populations in North Africa are not remnants of an ancestral continental population. Instead, they result from migratory events originating from the islands of Lanzarote and Fuerteventura. These back-colonization events likely occurred during the Middle Pleistocene, although this still requires confirmation.
This finding challenges the notion that islands merely "receive" genetic diversity from the continent. In this case, the Canary Islands actually generated new genetic diversity that subsequently spread back to the African mainland.
Ref. : Rincón-Barrado M., Villaverde T., Perez M.F., Sanmartín I. & Riina R., 2024 - The sweet tabaiba or there and back again: phylogeographical history of the Macaronesian Euphorbia balsamifera. Annals of Botany 133 : 883–903. https://doi.org/10.1093/aob/mcae001, available online at www.academic.oup.com/aob
Posted by Jean-Paul Peltier.
This publication presents a synthesis of research studies focusing on the various methods of argan tree (Sideroxylon spinosum L.) propagation. It is based on the PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), which is recognized for structuring and enhancing the transparency of systematic reviews and meta-analyses.
The literature search was conducted using the same keywords in the Scopus and Web of Science databases, selecting publications in English and French published between 2000 and 2024. Using the PRISMA method, 55 articles were selected, the majority of which (36) originate from Morocco, the native country of the argan tree.
The bibliometric analysis, performed using the VOSviewer software, enabled the visualization of links between the main keywords related to argan tree research. This map highlights the central position of germination, around which micropropagation, seed sowing, in vitro culture, and vegetative propagation are organized.
The discussion compares the different techniques: seed germination, which has a low success rate, is contrasted with the advantages of cutting and grafting, which allow for rapid rooting and greater genetic stability. In vitro micropropagation also appears to be a promising method, although it requires strict acclimatization conditions.
In conclusion, the study emphasizes the importance of combining traditional methods with modern biotechnological approaches to ensure the reproduction and sustainable conservation of this emblematic species.
Ref. : Tesse R., Boutaleb F., Bahlaouan B., Brett-Crowther M., El Antri S., & Boutaleb N., 2025 - Micrografting and Other Regeneration Techniques for the Argan Tree (Argania spinosa): A PRISMA-Based Systematic Review and Meta-Analysis. Natural Built Social Environment Health 1(3). DOI :10.63095/NBSEH.25.180342
Posted by Jean-Paul Peltier.
The article presents a list of ten non-native species recently identified in cumin crops in southeastern Morocco. These include Anthemis hyalina, Anthemis scariosa, Centaurea verutum, Carduus arabicus, Cota palaestina, Cota coelopoda, Hyoscyamus pusillus, Plantago exigua, Suchtelenia szovitsiana, and Silene coniflora. At this stage, most of these species are considered occasional exotics. However, Plantago exigua stands out due to its high invasive potential, spreading beyond cultivated areas. The article also provides essential data on the morphology, identification criteria, geographical distribution, and risk assessment associated with these newly detected species.
Ref. : Homrani Bakali H., Chatelain C. & Khamar H., 2025 - New non-native species recorded in cumin crop in southeastern region of Morocco. Botany Letters, DOI : 10.1080/23818107.2025.2506559 (18 Jun).
Posted by Jean-Paul Peltier.
Based on morphological characters, Santolina razaneae, a new Asteraceae species growing in the steppic habitats of eastern Morocco (Moulouya valley and High Plateaus), is described and illustrated. This species is distinguished from other Santolina species present in Morocco by its unique morphological traits, including elliptic leaflets and pinnate leaves with obtuse lobes, triangular, lacerate, and glabrous paleae, and florets with triangular, pale pinkish lobes. A key to the spontaneous Santolina species occurring in Morocco is provided.
Réf. : Homrani Bakali H., Chambouleyron M. & Leger J.-F., 2025 - Santolina razaneae (Asteraceae), a new steppic species from Morocco. Phytotaxa 693 (3) : 235–244. https://doi.org/10.11646/phytotaxa.693.3.4.
Posted by Jean-Paul Peltier.
Cette étude explore l’influence de la taille des conteneurs et du type de substrat sur les caractéristiques morphologiques, la biomasse, et la morphologie racinaire des jeunes plants d’arganier âgés d’un an. L’expérimentation a été menée dans la pépinière du Centre Régional de Recherche Forestière de Marrakech, située à 2,5 km au nord-est de la ville, sous bioclimat aride (et non semi-aride comme mentionné dans la publication).
Les résultats montrent que la croissance des plants d’arganier est maximale dans les conteneurs de plus grand volume (500 cm³), avec un substrat de culture spécifique composé d’un compost d’acacia (Acacia cyanophylla) à 100 % et un mélange à parts égales de terreau et de compost d’Acacia.
Cependant, comme souvent observé avec les plants élevés en conteneurs, ces derniers présentent des déformations de la racine pivotante, ce qui affecte la qualité globale des plants. Il convient de noter que le suivi des performances des plants après transplantation sur le terrain n’a pas été réalisé dans le cadre de cette étude.
Ainsi, le protocole optimal pour assurer une régénération efficace des arganiers reste à définir.
Réf. : Dallahi Y., Boujraf A., Smouni A. et al., Effects of container size and growing media on growth of argan (Argania spinosa) seedlings in Morocco. New Zealand Journal of Forestry Science (2024) 54:16 https://doi.org/10.33494/nzjfs542024x285x.
Posted by Jean-Paul Peltier.
Last modified on Tuesday, July 8, 2025 at 11h02.