120 days maturity after transplanting. Brassica juncea var. linearfolia. Tsa Tsai Round Mustard Seeds. Non-GMO, cool-season, annual, heirloom. Tsa Tsai Round is a popular and unique mustard variety from Southwest China and is called a Szechuan or Sichuan vegetable. It is also known as pressed or swollen stem or round stem mustard because the stem enlarges into thick tuber-like bumps just below the petioles. Its stem will grow 4-6 inches in diameter and weigh up to half a pound. This is perhaps the most well-known Asian mustard variety. ~18,400 seeds / oz.