Plant reproductive morphology is asexual, producing only spores. Similarly, flowers produced by the sporophyte may be described as "unisexual" or "bisexual", meaning that they give rise to either one sex of gametophyte or both sexes of gametophyte. The flower is the characteristic structure concerned with sexual reproduction in flowering plants (angiosperms). Flowers vary enormously in their construction (morphology). A "complete" flower, like that of "Ranunculus glaberrimus" shown in the figure, has a calyx of outer sepals and a corolla of inner petals. The sepals and petals together form the perianth. Next inwards there are numerous stamens, which produce pollen grains, each containing a
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