Bog Yellowcress - Rorippa palustris
Taprooted annual to short-lived perennial. Stems usually erect, 10–100 cm. Leaves basal and cauline; the lower leaves 3–15 cm long, petiolate, auriculate-clasping, oblanceolate, pinnately lobed and dentate; upper leaves similar, smaller, less divided and toothed. Vestiture of sparse, simple hairs below or plants glabrous. Petals yellow, 1.5–3 mm long. Fruit an ovoid silicle, 2–5 × 2–3 mm, glabrous; style 0.3–1 mm long; pedicels spreading, 3–10 mm long, longer than the silicle (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
Montana has varieties palustris
(Desv.) Butters & Abbe, and fernaldiana
Butters & Abbe
Wet, often disturbed soil of fields, roadsides and along streams, wetlands; plains, valleys, montane (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus rufocinctus
(Thorp et al. 1983).