Mountain alison

Alyssum montanum, commonly known as mountain alyssum or mountain madwort, is a low, mat-forming evergreen perennial herb in the family Brassicaceae native to mountainous regions of central and southern Europe and adjacent western Asia, where it grows on dry rocky slopes, screes, calcareous grasslands and alpine pastures from lowland habitats up to about 2500 metres elevation. The plant forms loose to dense cushions or mats 5 to 20 centimetres tall with prostrate to ascending woody-based stems that root at the lower nodes and arise from a thick taproot. The entire plant is silvery to grey-green from a dense covering of appressed stellate hairs that gives the foliage a felted texture. The leaves are alternate, simple and entire, oblanceolate to obovate, 5 to 20 millimetres long and 2 to 6 millimetres wide, broadest near the apex and gradually tapered to a narrow petiolar base. The fragrant golden-yellow four-petalled flowers are crowded into short, dense, rounded racemes at the stem tips in spring; each flower is 5 to 7 millimetres across with the typical cruciferous arrangement. The fruit is a small ovate to elliptic flattened silicula 3 to 4 millimetres long containing a few flat winged seeds.