Pensastaceae

Pensastaceae is a small and recently recognized family of flowering plants within the order Saxifragales. The family was formally described in 2016 by botanists studying phylogenetic relationships among Saxifragales, though its members were previously classified under other families, such as Saxifragaceae or Crassulaceae. The name *Pensastaceae* is derived from the genus *Pensastia*, its sole recognized genus, which contains only one species, *Pensastia palustris*.

*Pensastia palustris* is a perennial herb native to the eastern United States, particularly found in wetland habitats such as bogs, fens, and marshes. It is characterized by its basal rosette of leaves and slender, erect stems that can reach up to 30 centimeters in height. The plant produces small, white flowers arranged in dense clusters, blooming primarily in late spring to early summer. Its leaves are succulent, with a slightly fleshy texture, and exhibit a glossy appearance.

Phylogenetic studies indicate that Pensastaceae is closely related to the family Crassulaceae, sharing some morphological traits such as succulent leaves and a similar growth habit. However, molecular analyses have distinguished it as a distinct lineage, warranting its classification as a separate family. The ecological role of *Pensastia palustris* is primarily associated with wetland ecosystems, where it contributes to biodiversity and soil stabilization.

Due to its limited distribution and specialized habitat requirements, *Pensastia palustris* is considered a rare plant in parts of its range. Conservation efforts are occasionally directed toward preserving its natural habitats, particularly in areas where wetland drainage or habitat fragmentation threatens its survival. Further research is needed to fully understand its ecological interactions and evolutionary history.