Descriptions: 
Perennial herb, often use as annual and biannual plant.purple colour, type of plant is beautiful, often used of landscape design and flower border. As about florescence 4~10mounth. honey sunlight, full warm, not cold-resistant. Must be fertile, well-drained soil. due to seeds very small, so the proportionof 1 to 2mixed soil, needn't cover soil on the seeds.