We present a genome assembly of
Callitriche obtusangula
(Blunt-fruited Water-starwort; Streptophyta; Magnoliopsida; Lamiales; Plantaginaceae). The assembly consists of two haplotypes with total lengths of 1,574.50 megabases and 1,573.68 megabases. Most of haplotype 1 (98.42%) is scaffolded into 5 chromosomal pseudomolecules. Haplotype 2 was assembled to scaffold level. The mitochondrial sequences have lengths of 336.67, 10.09, 39.37 and 26.68 kilobases. Gene annotation of this assembly on Ensembl identified 23,816 protein-coding genes. This assembly was generated as part of the Darwin Tree of Life project, which produces reference genomes for eukaryotic species found in Britain and Ireland.