The standing asanas are the yoga poses or asanas with one or both feet on the ground, and the body more or less upright. They are among the most distinctive features of modern yoga as exercise. Until the 20th century there were very few of these, the best example being Vrikshasana, Tree Pose. From the time of Krishnamacharya in Mysore, many standing poses have been created. Two major sources of these asanas have been identified: the exercise sequence Surya Namaskar (the salute to the sun); and the gymnastics widely practised in India at the time, based on the prevailing physical culture.