Turritis glabra (Tower Mustard) - photos and description



Plants growing on a mossy, rocky hillside



Pods slightly elevated to perpendicular to the stem

Pods more or less circular in cross section

Basal leaf in above photo

Stem leaves with a diamond shaped base

Stem leaves oblong, sessile

General: Biennial plants with stout stems. The stems are glabrous towards the top, hirsute below.

Flowers: Flowers small, racemose, have four petals, are white with purple colouring at the tips. We measured flowers at 12 mm long and 6 mm wide.

Fruit: Circular in cross section or nearly so, narrow, usually straight, we measured a fruit at 31 mm long by 1 mm wide.

Leaves: Lower leaves whorled, upper leaves crowded on the stem. Leaves have a prominent mid-rib. Basal leaves with petioles, oblanceolate to oblong, measured to 20 mm long by 6 mm wide including petiole. Basal leaves are grey with appressed hairs. Stem leaves alternate, clasping, elliptical to ovate, often have a diamond-shaped base, measured sat 15 mm ong by 5 mm wide.

Height: Height listed in Budd's Flora to 60 cm, we measured plants to 20 cm tall.

Habitat: Cliffs, thickets, woods, and fields.

Abundance: Listed as fairly common in Checklist of the Vascular Plants of Saskatchewan. I think I have only seen this plant in the Cypress Hills.

Origin: Native.

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

How to identify this species: Fruit terete (circular in cross section) or nearly so.

When and where photographed: Photos were taken May 7th, 11th, and May 17th on a rocky slope in the Cypress Hills 400 km southwest of our home in Regina, SK.