I don't know the name of the flower I saw in front of a hotel. Please help tell me, thank you!

Kale, a biennial herb, is a horticultural variety of edible cabbage. The structure and shape are very similar to Chinese cabbage, except that the center of kale is not rolled into a ball. Plants cultivated for one year form rosette leaves, which blossom and bear fruit in the second year after low temperature in winter. The raceme is terminal and blooms from April to May. This is a flower spread by insects. The fruit is pod-shaped, oblate, and the seeds are spherical and brown, weighing about 4 grams. Horticultural varieties have various forms, which can be divided into high type and short type according to height; According to the shape of leaves, it can be divided into wrinkled leaves, wrinkle-free leaves and deeply lobed leaves; According to color, the edge leaves are emerald green, dark green, grayish green and yellowish green, and the center leaves are pure white, light yellow, flesh color, rose red and purple red. Kale is very popular in the United States because its calcium content is 10%, vitamin A 133% and vitamin C 134%. Known as the best vegetable for human body.