This grower is sure of this plant identification.
Quickly forms clumps of evergreen iris like foliage with charming spikes of yellow flowers. Good for structure and great for insects
Sisyrinchium striatum (Satin flower). The leaves are sword-shaped and are grey-green in colour. The flowers are produced in profuse, creamy- yellow blooms.
Grow them in full sun or semi shade with constant moisture along with good drainage.
Border, ground cover, walls, rock garden