Mustard relative native to mountains of central and southern Europe, Turkey. Gray, 2- to 5 inches-long leaves form a spreading evergreen mound 812 inches high. Dense clusters of tiny golden yellow flowers cover the plant in spring and early summer. Use as foreground plant in borders, in rock gardens, atop walls; plant about 112 feet apart. Poor soils or moderately fertile ones suit the plant perfectlyas long as drainage is good. Shear lightly (don't cut back stems by more than half) right after bloom. Generally hardy but may be killed in extremely cold winters. Short lived in hot, humid climates. Self-sows readily.
Selections include 'Citrina' ('Lutea'), with pale yellow flowers; 'Compacta', a compact grower with lemon-yellow blooms; 'Plena' ('Flore Pleno'), double flowered; 'Silver Queen', compact grower with pale yellow flowers; 'Sunnyborder Apricot', with apricot-shaded flowers; 'Dudley Nevill', similar in flower color to 'Sunnyborder Apricot' but with white-variegated leaves; and dwarf forms 'Goldkugel' ('Gold Ball'), 6 inches high, and 'Tom Thumb', 3 inches high.