Angelica acutiloba with distinct calyx and white corolla. However, the calyx is often reduced with obsolete calyx teeth. The flowers have five petals, sepals, and stamens. The white petals are often obovate to oblong. The inflorescences contain fifteen to forty-five pubescent rays, 1–10 cm in length, which surround about thirty small disk flowers. The peduncles which hold the entire inflorescence are glabrous or pubescent and 5–20 cm long. While the stalks of each single flower in the flower clusters called pedicels, are thin and often sessile. The whorl of bracts beneath the inflorescences is called involucre. It consists of phyllaries, modified bracts,
Surround channels Surround channels Surround channels are audio channels in surround sound multichannel audio. They primarily serve to deliver ambience and diffuse sounds in a film or music soundtrack. Dolby Stereo (1975) was the first standard cinema sound system using a single matrixed mono rear channel (note Disney's Fantasound from the 1930s used a surround channel). Dolby Surround (1982) was the first home audio system to use a rear channel. It and its successor, Dolby Pro Logic (1987), used a single rear surround channel, but often using two speakers connected in anti-phase or a dipole radiator, as shown in the speaker configuration