Amongst the most hardy and undemanding aquatic plants, vallisnerias are easily grown in most aquariums. Their easy requirements are nutrient bearing gravel, lots of light and careful initial planting (with their white crown bases barely above gravel. Vals are great for backgrounds, tank sides and central areas where high relief is desired. The genus is probably the most widely offered in the hobby; and the lowest cost to purchase and cultivate. Don't worry about killing them off, you will probably have to periodically thin out these plants to reduce their dense thickets. Distribution & Classification The genus is widely distributed over a large part of the globe, fresh to brackish, tropics to semi-temperate, naturally and through human introduction. Vallisneria are members of the monocotyledon family Hydrocharitaceae. This group that should be familiar to aquatic horticulturists as it also contains other important genera; Elodea (anacharis), the beautiful heart-shaped Limnobium and notorious Hydrilla verticillata, among others.

The vallisnerias are superficially similar to the equally popular and appropriate arrowheads, genus Sagittaria. These look-alikes have pointier leaves, whiter, thicker roots and different venation in their leaf structure. Sag's typically bear darker green, stiffer leaves than vals. There are about ten species of vallisnerias, but good luck sorting them out. There is much confusion in the trade and literature o ...

Continue to read all article at : http://www.wetwebmedia.com/PondSubWebIndex/vallisnerias.htm