Pond Water-Starwort

Description

Callitriche stagnalis is a perennial aquatic vascular plant species. Also known as pond water-starwort, C. stagnalis, may thrive in a variety of aquatic and subaquatic habitats, specially those exhibiting slowly moving to non-moving water. Although C. stagnalis does not pose a threat to humans, its reproductive rate may pose a threat to native vegetation in areas where it has been introduced, as the resulting dense vegetative mats frequently out-compete native species. Callitriche stagnalis is normally found in aquatic environments particularly in which there is little to no motion.C. stagnalis frequents lakes, ponds, salt marshes, and slow moving rivers and streams. This species is able to thrive in both fresh and brackish water habitats. Callitriche stagnalis is native to both Europe and North Africa, where it is widespread in aquatic and subaquatic habitats. C. stagnalis has been found in Europe, Northern Africa, The United States, Asia, Australia, New Caledonia, and New Zealand. The general appearance of C. stagnalis differs slightly depending on whether the plant being viewed was submerged or floating. Both exhibit long stems that vary in length from approximately 1 to 3 decimeters. These stems give rise to leaves that are oppositely arranged. The characteristic difference between the submerged and floating C. stagnalis is its leaf shape.Submerged leaves of C. stagnalis are linear, appearing long and thin with one vein running up the center.Floating leaves of C. stagnalis, however, may be spatulate to obovate in shape, which appear much wider that the typical submerged leaves, and contain a much larger number of veins (5-7).Growth of the leaves of C. stagnalis also differs depending on whether they are submerged or floatin Submerged leaves can grow 4 to 10 mm in length whereas floating leaves may only reach 2 mm in length. Submerged leaves are typically thin but may be wider in some cases making it harder to differentiate them from their floating counterparts which may grow 5 to 8 mm in width.