Myriophyllum sibiricum

Myriophyllum sibiricum is a species of water milfoil known by the common names shortspike watermilfoil, northern watermilfoil, and Siberian water-milfoil. It is native to Russia, China, and much of North America, where it grows in aquatic habitat such as ponds and streams. It generally grows over a meter long, its green stem drying white. It is lined with whorls of fanlike green leaves divided into many narrow, feathery lobes.

Description
The erect inflorescence is a spike of small flowers up to 8 cm long which grows above the water's surface.