Narcissus (plant) corona. Floral tubes can range from long and narrow in sections "Apodanthi" and "Jonquilla" to rudimentary ("N. cavanillesii"). Surrounding the floral tube and corona and reflexed (bent back) from the rest of the perianth are the six spreading tepals or floral leaves, in two whorls which may be distally ascending, reflexed (folded back), or lanceolate. Like many monocotyledons, the perianth is homochlamydeous, that is undifferentiated into separate calyx (sepals) and corolla (petals), but rather has six tepals. The three outer tepal segments may be considered sepals, and the three inner segments petals. The transition point between the floral tube and
MPEG Surround also successfully demonstrated. MPEG Surround's backward compatibility and relatively low overhead provides one way to add multichannel sound to DAB without severely reducing audio quality or impacting other services. Currently, the majority of digital TV broadcasts use stereo audio coding. MPEG Surround could be used to extend these established services to surround sound, as with DAB. Currently, a number of commercial music download services are available and working with considerable commercial success. Such services could be seamlessly extended to provide multichannel presentations while remaining compatible with stereo players: on computers with 5.1 channel playback systems the compressed sound files are