Seed are sometimes sold commercially while still enclosed within the hard wall of the fruit, which must be split open to reach the seed. Different groups of plants have other modifications, the so-called stone fruits (such as the peach) have a hardened fruit layer (the endocarp) fused to and surrounding the actual seed. Nuts are the one-seeded, hard-shelled fruit of some plants with an indehiscent seed, such as an acorn or hazelnut. Seeds are produced in several related groups of plants, and their manner of production distinguishes the angiosperms ("enclosed seeds") from the gymnosperms ("naked seeds"). Angiosperm seeds are produced in
Naked yoga and other ascetic groups in the dharmic religions. A notable example is the order of sadhus known as the Nagas who use nudity as a part of their spiritual practice of renunciation. The word "Nāga" comes from NAG (snake) which signifies power in Hindu philosophy. The word sadhu derives from sadhana meaning spiritual practice. Members of the sect considered nudity a way of rejecting the material side of life. Celibacy and disregard of the harsh outside conditions were among the key ideas of their philosophy. They practiced naked yoga to tame their desires, identify with their physical bodies and to