Revisiting Acalypha: Integrating global knowledge and taxonomy for drug discovery

This diverse genus of flowering plants holds significant medicinal relevance, and yet remains considerably understood.

Guest Blog Post by Lucía Villaescusa-González and Pablo Muñoz-Rodríguez

Since the first humans learned to distinguish the plant that cured a fever from the one that caused a funeral, we have amassed an extraordinary amount of information about the natural world. Whether used for food, medicine, or shelter, this ethnobotanical knowledge passed down through generations now serves as the foundation for modern experimental research.

Today, researchers explore the world’s plant chemical diversity seeking new compounds and species of medicinal or economic interest. However, discovering these resources and sharing the information effectively depends on one often-overlooked key: naming things correctly.

Taxonomy ensures that, when researchers identify a promising use of a plant, the rest of the scientific community can find that plant again, replicate the results, and build upon them. In a time of accelerated biodiversity loss, taxonomy provides the framework that allows us to document biodiversity and connect knowledge about species before they are lost.

For nearly two decades, our research group has focused on Acalypha, a remarkably diverse genus of flowering plants with approximately 450 species. It is the third largest genus in the family Euphorbiaceae —the same as cassava, poinsettia or the rubber tree— yet many aspects of its biology remain poorly understood. While numerous studies have pointed to the medicinal relevance of Acalypha, the information has historically been scattered across disconnected sources and regions.

Acalypha mollis growing at the Naciones Unidas National Park in Guatemala. Author: Gandhi Ponce Juárez – iNaturalist, CC0 licence (https://www.inaturalist.org/observations/234908619)

To fully explore a plant group’s potential, we must ensure our knowledge is organised and reliable. This is precisely where taxonomy becomes powerful. In a study recently published in PhytoKeys, we compiled, revised, and standardised existing knowledge about Acalypha uses published worldwide between 1816 and 2024.

Our review, published in the open-access journal PhytoKeys, revealed that nearly 25% of the studies we analysed contained at least one taxonomic error. These errors ranged from the use of non-existent names and already outdated synonyms at the time of publication to “impossible” data, such as species allegedly collected for research in countries thousands of kilometres away from their known distribution range.

By verifying every scientific name against current standards, we were able to provide the first standardised, reliable global synthesis of the genus. Furthermore, this process allowed us to clear the “noise” from the literature and identify exactly which species hold the most promise for future research.

Geographical distribution of Acalypha ethnobotanical knowledge. Top: number of studies with ethnobotanical information per country. Bottom: number of species with reported medicinal uses per country. Darker colours indicate higher values. Author: Villaescusa-González et al.

A clearer global picture

Once we brough this information together under a robust taxonomic framework, a much clearer picture of Acalypha medicinal uses emerged. We identified 62 species with documented medicinal uses across 55 countries. While the genus is used globally, pharmacological research is heavily concentrated in India, Nigeria, and Mexico.

In contrast, species-rich countries such as Brazil and Madagascar, with over 40 species each, remain significantly underrepresented. Also, while many species are used locally, a few are globally relevant: Acalypha indica, for example, is used to treat 23 different disease categories, while Acalypha wilkesiana, a common ornamental plant, is linked to 18 disease categories.

Our work revealed that these plants are used not just for human medicine; they are used in veterinary medicine, as pesticides targeting disease-carrying insects, and in ritual contexts. In human health, they most frequently target infectious and parasitic diseases, digestive tract issues, and respiratory symptoms.

Finally, we also detected a big gap between traditional use and modern research: of all species recorded in ethnobotanical surveys, 36 have never been studied in a laboratory. They represent a promising avenue for future research and drug discovery.

Acalypha argomuelleri, a shrub growing in the Peruvian Andes. Author: Pablo Muñoz-Rodríguez

Why this matters for the future

­The relationship between ethnobotany and experimental biology is widely recognised, and taxonomy plays a key role in bridging these fields. Accurate taxonomic knowledge is essential for ensuring scientific discovery and reproducibility.

When experimental research investigates plants that have been incorrectly identified, it leads to the perpetuation of errors in scientific literature. If pharmacological results are based on misidentified specimens, those experiments cannot be replicated, potentially misleading years of subsequent, expensive medical research.

Glandular hairs in Acalypha ecklonii, a species from Southern Africa. Author: Emma Ortúñez & Roberto Gamarra.

By integrating scattered ethnobotanical reports into a standardised, taxonomically reliable system, we wanted to provide a reliable map for all future Acalypha research. This study proves that precise identification is the basis of scientific discovery.

In an era of accelerated biodiversity loss, applying taxonomy to organise and validate the data we have today ensures the discovery of the medicines of tomorrow.

Original source

Villaescusa-González L, Cardiel JM, Montero-Muñoz I, Muñoz-Rodríguez P (2026) Revisiting Acalypha medicinal interest: ethnobotany, experimental studies, and the implications of taxonomic misuse pitfalls. PhytoKeys 270: 119-142. https://doi.org/10.3897/phytokeys.270.169087

Don’t forget to also keep yourself up-to-date with the latest discoveries described in PhytoKeys by signing up for the journal newsletter from the PhytoKeys homepage. You can also follow the journal on BlueSky and Facebook.

Pensoft Celebrates World Wildlife Day 2026 with Medicinal and Aromatic Plants

Medicinal and aromatic plants (MAPS) are essential for human health and ecological balance.

This World Wildlife Day, we are celebrating the role of medicinal and aromatic plants (MAPs), which are essential for both human health and ecological balance. To highlight this year’s theme – “Medicinal and Aromatic Plants: Conserving Health, Heritage and Livelihoods” – we have spotlighted six fascinating species from the open-access journal PhytoKeys.

Medicinal Marvels

The Coleus genus, a member of the Lamiaceae (mint) family, comprises approximately 294 species of perennial herbs and subshrubs native to the tropical and subtropical regions of the Old World, including Africa, Asia, and Australia. These plants are well-regarded for their diverse medicinal applications, and are traditionally employed to address respiratory issues such as coughs and bronchitis. The pictured Coleus harmandii species, native to Indo-China, shares the genus’ characteristic antioxidant and anti-inflammatory properties.

Coleus Harmandii. (Photo credit: Thamarat Phutthai).

Read more: Paton AJ, Mwanyambo M, Govaerts RHA, Smitha K, Suddee S, Phillipson PB, Wilson TC, Forster PI, Culham A (2019) Nomenclatural changes in Coleus and Plectranthus (Lamiaceae): a tale of more than two genera. PhytoKeys 129: 1-158. https://doi.org/10.3897/phytokeys.129.34988

Meanwhile, an interesting-looking parasitic plant named Balanophora xinfeniae, and found in the shaded forests of Motuo County in Tibet, exhibits similar properties. A study on its taxonomic identification notes the broader medicinal significance of the Balanophora genus. Indeed, species within this genus are historically used to treat ailments, including liver disorders, stomach aches and hemorrhoids. 

Balanophora xinfeniae. (Photo credit: Meng Li and Chen-Long Fu).

Read more: Fu C-L, Zhou J-N, Liao W-H, Zhang T, Xu B, Li M (2025) Balanophora xinfeniae (Balanophoraceae), a new species from Xizang, China. PhytoKeys 266: 241-252. https://doi.org/10.3897/phytokeys.266.147400

Perhaps the most interesting of the bunch are species within the genus Huperzia, commonly known as firmosses, which are highly valued for their ability to treat Alzheimer’s disease. While the newly-discovered species, Huperzia crassifolia, was identified during medicinal plant inventories in China, it belongs to a group of plants that have long been used in traditional Chinese medicine for cognitive health. Because this new species is a close relative of these established medicinal plants, it holds significant potential for future pharmaceutical research.

Huperzia crassifolia. (Photo credit: Zhi-You Guo).

Read more: Guo Z-Y, Liu H-M, Wang K-K, Fujiwara T, Liu Z-Y, Zhang X-C, Schneider H (2024) Huperzia crassifolia (Lycopodiaceae), a new species from China based on morphological characters and molecular evidence. PhytoKeys 246: 27-42. https://doi.org/10.3897/phytokeys.246.131046

Fragrant Frontiers

We now shift our focus to aromatic plants, beginning with Capsicum fruits. These are driven by a diverse range of organic compounds, responsible for their characteristic “bell pepper” scent. Pictured below, Capsicum cornutum is a unique pepper known locally in Rio de Janeiro as Pimentinha-do-mato (wild pepper). Its specific aroma is the product of rust-coloured outer hairs, which densely cover its stems and leaves. Unlike many common garden peppers, this species features a continuous ring of glandular hairs, which give it a distinct herbal scent.

Capsicum cornutum. (Photo credit: G.E. Barboza).

Read more: Barboza GE, García CC, Bianchetti LB, Romero MV, Scaldaferro M (2022) Monograph of wild and cultivated chili peppers (Capsicum L., Solanaceae). PhytoKeys 200: 1-423. https://doi.org/10.3897/phytokeys.200.71667

Plants within the genus Uvariodendron are also frequently characterised by the presence of aromatic compounds. Their scents are concentrated in the leaves, bark and flowers, ranging from spicy and peppery notes to distinct citrus or anise-like fragrances. These aromatic profiles have served as key diagnostic markers for botanists; for instance, species like Uvariodendron anisatum are named specifically for their scent. Interestingly, the fragrance emitted by the pictured Uvariodendron molundense aids in attracting many pollinators!

Uvariodendron molundense. (Photo credit: Ehoarn Bidault).

Read more: Dagallier L-PMJ, Mbago FM, Couderc M, Gaudeul M, Grall A, Loup C, Wieringa JJ, Sonké B, Couvreur TLP (2023) Phylogenomic inference of the African tribe Monodoreae (Annonaceae) and taxonomic revision of Dennettia, Uvariodendron and Uvariopsis. PhytoKeys 233: 1-200. https://doi.org/10.3897/phytokeys.233.103096

We end our series with the species Neocinnamomum citratum, a recently described evergreen tree from southwestern China. Unlike other Neocinnamomum species, which typically possess only a faint fragrance, N. citratum is characterised by a strong lemon fragrance present throughout its branches, leaves and bark. This potent aroma is reflected in its specific epithet, “citratum”. Due to these aromatic properties, the species has practical local utility; in Malipo County, for instance, residents collect the branches and leaves to use as spices for cooking. 

Neocinnamomum citratum. (Photo credit: Lin et al.).

Read more: Lin W-L, Zhang Z-Y, Deng C-Y, Xu W-B, Liu B (2026) Taxonomic notes on Neocinnamomum (Lauraceae): a new combination and a new species from southwestern China. PhytoKeys 269: 209-220. .https://doi.org/10.3897/phytokeys.269.177163

From the life-saving potential of Huperzia crassifolia to the cultural heritage of Neocinnamomum citratum, these selected species demonstrate that the conservation of wildlife is deeply intertwined with our own survival. Through the protection of these medicinal and aromatic plants, we can safeguard the health and heritage of our planet for generations to come.

Cover image: Passiflora juliana – Porter-Utley K (2014) A revision of Passiflora L. subgenus Decaloba (DC.) Rchb. supersection Cieca (Medik.) J. M. MacDougal & Feuillet (Passifloraceae). PhytoKeys 43: 1-224. https://doi.org/10.3897/phytokeys.43.7804

Don’t forget to also keep yourself up-to-date with the latest discoveries described in PhytoKeys by signing up for the journal newsletter from the PhytoKeys homepage. You can also follow the journal on BlueSky and Facebook.