Supplemental Material for Landis <i>et al</i>., 2025

<i>Calochortus tolmiei </i>Hook. &amp; Arn.<i>, </i>a bulbous monocot with cat’s ear flowers in the angiosperm family Liliaceae, is a perennial herb native to northern California, Oregon, and Washington. <i>Calochortus</i> exhibits substantial morphological and karyotype diversity with multiple floral forms and a haploid chromosome number varying from six to 10. Here, we present the first high-quality reference assembly in Liliaceae for <i>C. tolmiei</i>, with a scaffolded assembly of 2.9 Gbp with a N50 of 296 Mbp. Notably, 92% of the assembled genome is scaffolded into 10 pseudomolecules, matching the documented chromosome count of <i>C. tolmiei. </i>The genome contains 31,049 protein-coding genes, with 86.2% being functionally annotated. The closest reference-quality genome assembly to <i>C. tolmiei</i> is from <i>Chionographis japonica </i>(Willd.) Maxim. (Melianthiaceae), which diverged approximately 83 MYA, providing a valuable genomic resource in the Liliales, an order which lacks genomic resources.