Website/Catalog  (2018)  
 
Rosa gymnocarpa Nuttall var. serpentina Ertter & W. H. Lewis, Madroño. 55: 174, fig. 2. 2008.
Gasquet rose
Stems (1–)3–6(–13) dm. Leaves 2–6(–8) × 1.5–3(–4) cm; stipules 5–11 mm; leaflets 5(–7), often bluish green or red-tinged, ± leathery, terminal: petiolule 2–10 mm, blade broadly elliptic to obovate or ovate to nearly orbiculate, 4–20 × 4–20 mm, apex usually broadly obtuse to rounded, sometimes nearly truncate. Pedicels 10–15 mm, eglandular or stipitate-glandular (in same inflorescence). Flowers 2 cm diam.; petals 8–10 × 6–10 mm. Hips irregularly ovoid to elongate-ellipsoid. Achenes 1–4.
Flowering Apr–Jun. Full sun in roadsides, ridges, and other openings in chaparral and stunted forests on ultramafic substrates; of conservation concern; 400–1500(–2300) m; Calif., Oreg.
Variety serpentina is the form that usually occurs in full sun on ultramafic substrates in the Siskiyou Mountains of northwestern California and southwestern Oregon.

Article (magazine)  (2016)  
 
 Subspecies gymnocarpa is further divided into var. gymnocarpa and var. serpentina Ertter & W. H. Lewis.