The criterion level, often abbreviated as Lc, is the steady noise level permitted for a full eight-hour work shift. This is 85 dB(A) in most jurisdictions, but it is 90 dB(A) in Quebec and 87 dB(A) for organizations that follow the Canadian federal noise regulations.
Royal Catchfly (Silene regia) This striking plant may grow as high as five feet, with bright red flowers. It flowers from May through September, and can be seen in remnant prairies and open woods. In Missouri, it is known only in the Ozarks.
The Ozark Highlands area, covering nearly 47,000 square miles (122,000 km2), is by far the most extensive mountainous region between the Appalachians and the Rocky Mountains. Together, the Ozarks and Ouachita Mountains form an area known as the U.S. Interior Highlands, and are sometimes referred to collectively.