Vulgare

Spear Thistle
-twin to Cirsium

habitat has been affected by siltation, erosion, polluted runoff, impoundment, channelization, and habitat fragmentation. Due to these environmetal changes, even common and widespread species have declined dramatically from historic levels. Mussels are important indicators of aquatic ecosystem health. Their complex life cycle requires a healthy fish community, stable substrates, and relatively clean water. Changes in water quality, channel stability, or fish density and diversity are usually reflected by a decline in abundance or a loss of species within the mussel community. Monitoring the health and diversity of the mussels within a drainage system is an important tool in aquatic ecosystem management.
species beds containing thousands of mussels per square meter. The Asian Clam is native to Asia, but can now be found in rivers, streams, lakes, ponds, etc. throughout the continental United States. The glochidia of the Asian clam go through a planktonic stage rather than a parasitic phase. Therefore, these mussels do not require a host fish. Also, the Asian clam is a hermaphrodite, and is capable of self fertilization.

References:
Hartfield, E. 2004. FRESHWATER MUSSELS OF