A lake is an area filled with water, localized in a basin, surrounded by land, and set apart from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger oceans, they do form part of the Earth's water cycle. Lakes are distinct from lagoons, which are generally coastal parts of the ocean. Lakes are typically larger and deeper than ponds, which also lie on land, though there are no official or scientific definitions. Lakes can be contrasted with rivers or streams, which usually flow in a channel on land. Most lakes are fed and drained by rivers and streams.
Natural lakes are generally found in mountainous areas, rift zones, and areas with ongoing glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers, where a river channel has widened into a basin. Some parts of the world have many lakes formed by the chaotic drainage patterns left over from the last ice age. All lakes are temporary over long periods of time, as they will slowly fill in with sediments or spill out of the basin containing them.
Many lakes are artificial and are constructed for industrial or agricultural use, for hydro-electric power generation or domestic water supply, for aesthetic or recreational purposes, or for other activities. (Full article...)
Lobelia dortmanna, Dortmann's cardinalflower or water lobelia, is a species of flowering plant in the bellflower family Campanulaceae. This stoloniferousherbaceousperennialaquatic plant with basal leaf-rosettes and flower stalks grows to 0.7–2 m (2.3–6.6 ft) tall. The flowers are 1–2 cm long, with a five-lobed white to pale pink or pale blue corolla, produced in groups of one to ten on an erect raceme held above the water surface. The fruit is a capsule 5–10 mm long and 3–5 mm wide, containing numerous small seeds.
The leaves are almost cylindrical, blunt, 2.5–7.5 cm long and evergreen. They have no functional stomata. It is one of several unrelated species of plants from low nutrient lakes known as isoetids, owing to their superficial similarity to Isoetes. The leaves of Lobelia dortmanna are, however, easily distinguishable from those of other isoetids in having only two air-canals (Isoetes having four and most others several) and in the presence of milky sap. The plant has the unusual ability of removing carbon dioxide from the rooting zone rather than from the atmosphere. (Full article...)
Image 15A view of the southern polar plain of Mars. The area where a subglacial lake has been detected is highlighted. Image credit: USGS Astrogeology Science Center, Arizona State University (from Subglacial lake)
Image 23Lakes can have significant cultural importance. The West Lake of Hangzhou has inspired romantic poets throughout the ages, and has been an important influence on garden designs in China, Japan and Korea. (from Lake)
Image 24The Caspian Sea is either the world's largest lake or a full-fledged sea (from Lake)