Plants clonal strategies are well associated with aridity gradients: insights from Lamiaceae family in the SW and Central Asia.

Clonal reproduction is often considered advantageous in stressful environments. While considerable research has explored how clonality supports plant survival in wet and cold conditions, its role in arid and semi-arid conditions remains underexplored. To address this gap, this study examines the distribution and diversity of clonality as a key component of belowground growth form (BGF) along aridity gradients across SW and Central Asia using the species-rich Lamiaceae family as a model. Data were collected from 281 species with a variety of BGFs occurring in a broad range of habitats. Data on BGFs were collected primarily in the field, with additional data from herbarium records and digital databases. BGFs were categorized into hypogeogenous rhizomes, epigeogenous rhizomes, stolons, and non-clonal types. Species distribution data were obtained from regional floras and the Global Biodiversity Information Facility (GBIF) and analysed using precipitation-related bioclimatic variables. Clonal species of the Lamiaceae family, particularly those with hypogeogenous and epigeogenous rhizomes, were more prevalent in extreme environments, both water-limited and moisture-rich, highlighting their adaptation to stressful conditions. They thrived in arid habitats like deserts and semi-deserts as well as wet habitats such as forests or wetlands. Non-clonal species were concentrated in the centre of the gradient, dominating montane steppe shrublands where water availability was moderate and seasonally variable. Clonal plants are not avoiding arid environment. This is particularly noteworthy for species with hypogeogenous rhizomes that have been shown to prefer wet conditions in temperate regions. The exact mechanisms that permit their specialization to wet or dry conditions is to be further studied experimentally. These findings highlight how climate change may differentially affect species based on their BGFs.