Syn.: Lesquerella arenosa (Richardson) Rydb., Lesquerella lunellii A. Nelson, Lesquerella macounii Greene, Lesquerella rosea Greene, Lesquerella versicolor Greene, Vesicaria arenosa Richardson
Family: Brassicaceae Burnett

Physaria arenosa

Distribution: North American species, endemic to the central part of the continent, in Alberta, Saskatchewan, Manitoba, Dakotas, Nebraska, Montana, Colorado and Wyoming. Two subspecies are recognized with minor difference in trichomes of the fruit valves.

Ecology: Open prairies, dry hillsides and open gravel or sandy (arenosa) flats at elevations from 500 to 1500 m. Blooms from May to July.

Description: Short-lived perennial herb, to 10 cm high, from a single or branched caudex. Stems 10–25 cm long, prostrate to ascending, from an open rosette, densely pubescent by silvery, star-shaped trichomes. Basal leaves oblanceolate, 1.5–5 cm long, margins smooth or shallowly dentate, covered with silvery trichomes; stem leaves alternate, linear, 1–2.5 cm, margins smooth, trichome covered. Inflorescence a terminal raceme, flowers yellow, pinkish with age, tetramerous; sepals eliptic or oblong, 4–6 mm; petals obovate, 6–9 mm. Fruit is a subglobose silique, 3–6 mm long, fruiting pedicels elongated to 7–10 mm, curved; seeds slightly flattened.

Physaria arenosa
Physaria arenosa
Physaria arenosa
Physaria arenosa

These images were taken in Canada, Alberta, Calgary, Confluence Park (June 2013).