It is a submerged plant with slender, branching stems about 20–70 cm (8–28 in) long. The light green, narrow leaves are up to 6 cm (2 in) long and 1-2mm wide, slightly broadening at the tip. The leaves which can float on top of the water, are shorter and wider, they are also light brownish or pinkish green.[3]
It has tiny inconspicuous green flowers and fruits,[4] and has a flowering period of between May and October.[5] or between April and September in the UK.[4]
The Latin specific epithethamulata is derived from hamatus meaning "with hooks" or "hooked",[7] referring to the hooked end of the leaves.[5]
Distribution
Callitriche hamulata is native to a wide area, which stretches from Greenland,[2][8] and Iceland,[3] through Europe to North-western Africa.[2]
It is widespread and fairly frequent in Britain, particularly in south eastern England.[4]
Habitat
It is found in rapidly flowing streams,[9] which are well oxygenated, and freshwaters, from sea level to about 1,200 m (3,900 ft) above sea level.[5]
This plant can grow in shallow waters and can also adapt to a deeper water level, especially after flooding.[3]
It can also be found in or near ponds, ditches, in still or slow moving water.[4]