Moss Taxonomy in the Molecular Era
21 November 2025
Moss Taxonomy in the Molecular Era
21 November 2025
Written by:
Dr. Nik Norhazrina Nik Mohd Kamil
Senior Lecturer
Department of Biological Sciences & Biotechnology,
Faculty of Science & Technology,
Universiti Kebangsaan Malaysia
Nur Amirah Athirah Mohd Khir
PhD Student
Faculty of Science and Technology,
Universiti Kebangsaan Malaysia
Taxonomy is the science of classifying the immense diversity of life on Earth. It builds an essential framework for identifying, naming, and classifying moss species, providing a system to organise living things from individual species to broader groups based on their morphology. Taxonomic studies also enable scientists to document and understand the diversity of mosses in various habitats and geographical regions, leading to more comprehensive and in-depth studies, especially regarding their significant ecosystem functions.
Mosses, a diverse group of non-vascular plants in the division of Bryophyta, play a significant ecological role in terrestrial ecosystems and everywhere. Although small, they serve as sensitive bioindicators of environmental health, facilitate nutrient cycles, and represent a major reservoir of global biodiversity. Further study in moss taxonomy is needed to understand their evolutionary history, ecological interactions, and potential biotechnological applications, thereby ensuring a sustainable future.
Certain moss species have traditional medicinal uses, as well as potential biotechnological applications, particularly for their economic value, such as biofuels, bioremediation, and horticulture. Correctly classifying mosses leads to further study, specifically the identification of species used for medicinal research and industrial purposes, which enables their practical application in various biotechnological fields.
Figure 1: A multi-species moss colonising a tree trunk, demonstrating high microhabitat diversity
Figure 2: Sphagnum moss that used as surgical dressing during First and Second World War
Traditionally, moss taxonomy is mainly based on morphological features observable by microscopy. These include characteristics related to the size of the plant, form of the leaves, cell structure, arrangement of leaves and branches (gametophores), and reproductive structures (sporophytes). Detailed morphological studies are crucial for differentiating closely related species and describing new species. Microscopic examination of moss tissues and cells provides insights into their internal structure, which may be informative for taxonomy. In recent decades, molecular methods have been added to classical ones in plant taxonomy. While taxonomy relies on morphological characteristics for plant classification, molecular study relies on chromosome number, physiological characteristics, biochemical properties, and genetics.
Despite the presence of molecular studies during this era, plant taxonomy remains important and relevant for several reasons. It provides a conventional yet standardised system to identify and classify plant species based on their morphological characteristics, which can be observed either microscopically or under magnification. Field botanists and ecologists rely on plant taxonomy to identify species in the wild, which is essential for establishing a preliminary understanding in ecological research, conservation planning, and environmental monitoring. Morphological identification provides on-the-spot results, as the name of the species can be identified by sight, making it quick and practical. In contrast, despite offering high-precision data, molecular methods are often costly, time-consuming, and require specialised laboratory equipment to run the analysis. The analysis was also restricted to a limited number of samples at a time. Yet, the utility of any molecular study is contingent upon correct initial specimen identification. If a non-targeted species is collected, subsequent molecular data will be irrelevant, rendering the entire process inefficient and scientifically unsound.
Figure 3: Conducting a detailed morphological observation of a moss specimen using a microscope, a fundamental practice in traditional species identification
Conversely, without knowledge of the taxonomy of targeted plant species, there will be an inefficient collection of plant material, potentially including non-target species. This therefore demonstrates the importance of plant taxonomy even in the era of advanced molecular studies. This leads to the time-consuming and resource-intensive collection of non-target species, resulting in wasted efforts, money, and time when processing, sequencing, and analysing the non-targeted species. Genetic data may yield inaccurate or confusing results, leading to incorrect deductions about genetic relationships, diversity, and evolutionary history. Additionally, the collection of plant materials without proper taxonomic identification has significant implications for both ethical and conservation efforts. Overharvesting of rare and endangered species, whether inadvertently or aggressively, can harm their survival in the wild. Secondly, it is crucial to determine the exact species being collected to follow legal and conservation guidelines, as laws or treaties may protect some plants. Good taxonomy simplifies research efforts, whereby species-specific identification reduces redundancy and the need for repeated research on the same misidentified or misclassified species.
Now, it plays a major role in verifying and interpreting the results of molecular phylogenetic research, especially when the findings contradict the classification systems or lack clear morphological support from any clade. Reliance on molecular data alone may lead to misclassification due to errors such as specimen contamination or misidentification. Therefore, taxonomists with their expertise in plant morphology play the most important role during this process. They do this through the careful study and examination of plant morphology (plant colour, leaf shape, branch pinnation, male and female gametangia) and growth patterns to either support or refute the findings proposed by molecular data. Cross-referencing between genetic results and physical characteristics can be used to detect inconsistencies that potentially reveal errors in molecular studies. Such accuracy in taxonomy ensures that correct species identifications are maintained and cannot be jeopardised by errors in genetic data. Therefore, this approach enhances the general reliability of a taxonomic work, supporting more robust and precise botanical research and conservation efforts.
In conclusion, taxonomic studies remain an essential foundation for plant biology, despite the current trend toward molecular studies. Correct identification and classification of targeted species by the taxonomist ensures the similarity of samples for molecular analysis. By having a solid taxonomic knowledge, the collection of non-targeted species can be avoided, thereby preserving wild resources and ensuring the validity of molecular data. A combination of taxonomic knowledge followed by confirmation from molecular techniques contributes to a better understanding of plant diversity and evolution. Lastly, accurate species identification is essential for practical conservation efforts, accurate biodiversity documentation, and compliance with laws and ethical standards in plant collection.
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