Turritis glabra

English: Tower rockcress; Tower-mustard; Towercress.
Name: Turritis comes from Latin for tower as a reference to the narrow growth and leaves and fruits upright.
Synonym: Arabis glabra.
Region: Europe, Germany, Austria, Switserland; Asia, Turkey, Iran, central Asia, Siberia; Korea, Japan, Mongolia, Manchuria, north-central China, southeast China, Xinjiang, Nepal, western Himalayas; Africa, Algeria, Kenya, Morocco, Rwanda, Tanzania, Uganda, Congo, South Africa; North America, Canada, western United States; introduced to Australia.
Habitat: poor chalky, sandy soils; open situations.
Content: glucosinolate.BotanyHerb; tall, slim, grey-green; biennial to short lived perennial; 40 to 120, 30 to 150 cm tall.
Root: tap-root and fibrous side-roots.
Stem: several, erect, unbranched; grey in the lower parts with simple hairs, but green and glabrous above.
Leaves: in a basal rosette initially, later alternately; basal leaves are blunt, spatulate to oblanceolate, toothed or pinnatifid, up to 15 cm long, 1 to 3 cm wid,; with hairs on the upper surface; stem and branch leaves become progressively smaller,less divided and more pointed, clasping the stem, lanceolate or oblong-elliptic, or fully egg shaped, wider base than end (ovate).
Inflorescence: terminal raceme; numerous small flowers.
Flower: creamy or white; petals four, pale yellow, up to 2 cm long; pedicels small, up to 2 cm long; sepals four, greenish, about 5 mm long; 6 stamens; 1 style.
Fruit: greenish, long, flattened, narrow silique, up to 8 cm long, 1.7 cm wide; held vertically beside the stem; with two rows of seeds in each valve.