Arabis pycnocarpa (Hirsute Rock Cress) - photos and description






Basal leaves in above photo

Stem leaf in a above photo

General: Biennial or perennial plant with an upright growth habit, a basal rosette of leaves and simple stems. Lower stem hirsute, upper stem glabrous.

Flowers: Flowers in a terminal raceme, white, measured to 8 mm diameter.

Fruit: Pods flat, erect, measured to 3.5 cm long and 1 mm wide.

Leaves: Cauline leaves alternate, sessile, oblong, stem leaf highlighted in photo above was 2 cm long and 4 mm wide. Basal leaves oblanceolate, have short petioles, a basal leaf was measured at 2 cm long and 5 mm wide.

Height: Height listed in Budd's Flora to 60 cm. We measured plants to 28 cm tall.

Habitat: Moist grassland.

Abundance: Listed as common in Checklist of the Vascular Plants of Saskatchewan.

Origin: Native.

How to identify this species of Arabis: Hirsute; pods erect, 1 mm wide, flat. Hirsute = coarse, spreading hairs. (Taxonomic Reminder for Recognizing Saskatchewan Plants).

Synonym: Listed in many of the field guides we use as Arabis hirsuta.

When and where photographed: The above photos were taken June 26th, edge of dry creek bed, south slope of the Cypress Hills about 450 km southwest of our home in Regina, SK.