Glossary of plant morphology others may form a tight spiral, or whorl, around the flower stem. First, at the base, are those non-reproductive structures involved in protecting the flower when it is still a bud, the sepals, then are those parts that play a role in attracting pollinators and are typically coloured, the petals, which together with the sepals make up the perianth (perigon, perigonium). If the perianth is differentiated, the outer whorl of sepals forms the calyx, and the inner whorl of petals, the corolla. If the perianth is not differentiated into sepals and petals, they are collectively known as tepals. In some
Surround sound same number of channels of source and destination; however, one-to-one, channel-to-speaker, mapping is not the only way of transmitting surround sound signals. The transmitted signal might encode the information (defining the original sound field) to a greater or lesser extent; the surround sound information is rendered for replay by a decoder generating the number and configuration of loudspeaker feeds for the number of speakers available for replay – one renders a sound field as produced by a set of speakers, analogously to rendering in computer graphics. This "replay device independent" encoding is analogous to encoding and decoding an Adobe PostScript