Changes in stool color alone do not cause symptoms. The underlying cause of the change in stool color, texture, or form is responsible for any symptoms. Bowel movements are usually light to dark brown in color, and there is moderate variation among individuals with respect to stool color, quantity and form.
Plants in the Twilight Zone As the amount of light decreases, the size and complexity of plant life also decreases. So whereas there may be flowering plants growing in the entrance zone, the twilight zone is typically marked by mosses and ferns.
A limited number of ferns tolerate full sunlight; however, frequent watering and consistently moist soil is critical. Sun-tolerant ferns include cinnamon fern (Osmunda cinnamomea) which reaches heights of 24 to 36 inches and grows in USDA zones 2 through 10.assel fern (Polystichum polyblepharum) is a striking, 18- to 24-inch fern that grows best in full or partial shade. Tassel fern grows in USDA zones 5 through 8. A sturdy fern that prefers shade, deer fern (Blechnum spicant) grows in USDA zones 5 through 8.