Abstract
The narrow-leaf bur-reed (Sparganium angustifolium Michx.), a member of the Typhaceae family, is an ecologically important species in temperate Northern Hemisphere aquatic ecosystems. As a phylogenetically basal taxon within the order Poales, S. angustifolium is critical for understanding evolutionary adaptations to aquatic environments. While molecular mechanisms of aquatic adaptation have been extensively studied in Alismatales, genomic resources for basal Poales remain scarce. Here, we present the first chromosome-level genome assembly of S. angustifolium, comprising 486.52 Mb with 99.94% coverage across 15 chromosomes. The assembly demonstrates high continuity, with both contig and scaffold N50 values reaching 33.25 Mb. Genome annotation identified 23,767 protein-coding genes and revealed that repetitive sequences represent 70.16% of the genome. Our findings provide valuable genomic resources for comparative studies of plant adaptation to aquatic environments across different evolutionary lineages.