Arctostaphylos (Ericaceae) species, commonly known as manzanitas, are an invaluable fire-adapted chaparral clade in the California Floristic Province (CFP), a world biodiversity hotspot on the west coast of North America. This diverse woody genus includes many rare and/or endangered taxa, and the genus plays essential ecological roles in native ecosystems. Despite their importance in conservation management, and the many ecological and evolutionary studies that have focused on manzanitas, virtually no research has been conducted on the genomics of any manzanita species. Here, we report the first genome assembly of a manzanita species, the widespread Arctostaphylos glauca. Consistent with the genomics strategy of the California Conservation Genomics project, we used Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology to produce a de novo assembled genome. The assembly comprises a total of 271 scaffolds spanning 547Mb, close to the genome size estimated by flow cytometry. This assembly, with a scaffold N50 of 31Mb and BUSCO complete score of 98.2%, will be used as a reference genome for understanding the genetic diversity and the basis of adaptations of both common and rare and endangered manzanita species.

A number of factors can blur boundaries, including hybridization, introgression, local adaptation, and phenotypic plasticity (Grant, 1972;Harrison and Larson, 2014). These factors can result in highly variable populations and species complexes, which include a range of phenotypes that cannot be easily divided into distinct groups using standard genetic, morphological, or ecological criteria.Eastwood manzanita (Arctostaphylos glandulosa Eastw., Ericaceae), a widespread tetraploid shrub found in the chaparral of southern Oregon, California, and the Baja California (MX) peninsula, is a phenotypically complex system in which delimiting subspecies has been challenging (

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