Here, ‘DT plants‘ refers to vascular plants able to tolerate the desiccation of their vegetative tissues, or more precisely, to dry to a quiescent state and resume normal cellular function when rehydrated. In this process, they lose up to 95% of their relative water content, reaching water potential levels below −100 MPa with little or no biomass loss. Although a rare response among vascular plants, desiccation tolerance spans across diverse clades in the phylogeny of vascular plants, resulting from multiple independent evolutionary events. They are particularly diverse in regions such as Southeast Brazil, East-South Africa, and Madagascar, although not commonly found in every vegetation type. Their remarkable strategy confers DT plants the capacity to grow in environments where water shortages are often or intensive enough to cause irreversible damages to most vascular plants, such as rock outcrops and forest canopies.
 

The ability of organisms to tolerate desiccation has long intrigued scientists. In 1702, Anthony von Leeuwenhoek expressed his surprise in a letter, describing living organisms (i.e., rotifers) in a dry sediment he had re-moistened. Yet, despite this early discovery, it took over 200 years for desiccation tolerance to be discussed in vascular plants. The first studies on vegetative tissues of vascular plants are dated 1914 for ferns and 1921 for angiosperms. Nowadays, we have a deeper understanding of the different mechanisms that allow DT plants to tolerate desiccation, but our knowledge remains noticeably biased toward certain taxa and geographic regions. Reducing these biases and filling the current knowledge gaps is highly relevant. This is especially important if we consider that research on DT plants holds immense promise for fields such as agriculture and biotechnology, e.g. by offering insights to engineer drought-resistant crops and address food security under climate change scenarios, or to improve vaccine stabilization.

The DT plants network is a global initiative dedicated to (1) fostering a collaborative and interdisciplinary community connecting researchers and other key stakeholders; (2) facilitating the information sharing about known species and their distribution patterns across geographical and environmental gradients; and (3) supporting the identification of knowledge gaps in the study and conservation of DT plants. 

The data supporting this resource was compiled through a multi-step process. First, we compiled a global species list of DT plants. For that, we conducted an extensive literature review (including grey literature) to identify all studies citing DT plant species according to our definitions of desiccation tolerance. This species list was harmonized following the taxonomic backbone provided by the World Checklist of Vascular Plants (WCVP; please see Govaerts et al. 2021 for more details). Since it is not our intention to engage in ongoing taxonomic debates but to facilitate the information sharing about known species, we have also attempted to incorporate commonly used synonyms found in the literature. Then, for every DT plant in our resulting species list, we identified their distribution patterns across geographical and environmental gradients. For that, we integrated all known occurrence records for each species from global databases, such as the Global Biodiversity Information Facility (GBIF). The retrieved raw data underwent a cleaning routine in order to remove duplicated, erroneous (e.g., records located within oceans, please see Zizka et al. 2019 for more details), and uncertain records (e.g., records assigned to localities where species are not expected to naturally occur according to Plants of the World Online – POWO). While we value citizen science, records from these initiatives were not included in our database. The resulting occurrence records were used to generate species distribution hypotheses according to two complementary modeling techniques: Maxent and Inverse Distance Weighting (IDW; please see Bondi et al. 2025 for more details). We also used the resulting occurrence records to obtain information about the species distribution across environmental gradients with the aid of global databases such as WorldClim, CHELSA, and WoSIS. Lastly, we attempted to identify knowledge gaps in the study and conservation of DT plants in three different ways: (1) identifying the literature bias towards certain taxa, (2) assessing the discrepancy between the species data collection and their expected occurrence across the World Geographical Scheme for Recording Plant Distributions (WGSRPD) according to POWO, and (3) evaluating the lack of conservation assessment in global (e.g., IUCN) and local initiatives (CNCFlora).

Desiccation tolerance is rare in vascular plants, but it has re-evolved multiple times within the tracheophytes phylogeny. For instance, we can find desiccation-tolerant vascular plants in fern-allies (like Selaginellaceae), ferns (like Hymenophyllaceae, Pteridaceae and Polypodiaceae), monocots (like Cyperaceae, Poaceae, and Velloziaceae), and eudicots (like Gesneriaceae and Linderniaceae). They are found worldwide, although their diversity increases in the tropics. Desiccation-tolerant vascular plants employ important responses to protect their cells from irreversible damage and to repair damage caused by drought. Such responses vary from morphological (like xylem designs that allow leaves to fold or shrink when desiccated) to metabolomic (like proteins or sugars that are accumulated to stabilize cells under low water contents). The importance of such traits (and their possible interactions) to explain ecological patterns is still to be better understood.