Cardamine holmgrenii Al-Shehbaz, Harvard Pap. Bot. 11: 275. 2007. TYPE: United States, Oregon, Baker County: Blue Mountains, boggy slopes 3 miles below (north) Anthony Lake, Elkhorn Ridge, 9 Aug 1946, Basset Maguire & Arthur H. Holmgren 26941 (holotype, NY!; isotype, UTC).

Herbs, perennial, glabrous throughout. Rhizomes slender, 0.5–1 mm in diam.; stolons absent. Stems 1.5–2 dm, erect to ascending. Leaves all cauline, 3 or 4, compound, 3- or 5-foliolate; petiole 0.5–1.7 cm, base not auriculate; terminal leaflet obovate to lanceolate, becoming linear in uppermost leaves, 1.3–2.3 cm × 2–8 mm, base cuneate, margin entire subapically 1- or 2-toothed, petiolule 3–5 mm; lateral leaflets linear to linear-lanceolate, 0.9–1.5 cm × 1–3 mm, entire. Racemes ebracteate; fruiting pedicels ascending to suberect, 5–14 mm. Sepals oblong, 1.2–1.5 × 0.6–0.8 mm, erect, base of lateral pair not saccate; petals white, oblanceolate, 2–2.5 × 0.8–1 mm, not clawed, apex rounded; median filament pairs 1.5–1.8 mm, lateral pair 1–1.2 mm; anthers ovate, 0.2–0.3 mm. Fruit linear, 1–2 cm × ca. 1 mm; valves glabrous; style 0.5–0.7 mm; ovules and seeds 16–24 per fruit. Seeds brown, oblong, 1.2–1.5 × 0.8–1 mm.

Flowering: Jul–Aug.

Habitat: boggy slopes.

Distribution: United States (E Oregon/Baker Co.).

Notes: known only form the type gathering.