In still and slow-flowing water and at the margins of lakes, Mare’s-tail is an aquatic species which grows on rhizomes. It has stems which are stout, round, spongy and erect and they bear shiny, narrow, strap-shaped, dark-green leaves in whorls of 6-12. At the base of each leaf is a very tiny, solitary, greenish flower. There are no petals or sepals and a plant can often bear both male flowers – with one reddish anther – and female flowers – with a single white style. The flowers can be seen – best with a hand lens – in June and July. The fruit is a tiny, green nut. Mare’s-tail is a perennial, native plant which seems to be found more in the northern two-thirds of Ireland than the southern. It shows up to 1 metre of itself above the waterline. When it grows in mud, it is generally a good bit smaller. It belongs to the Hippuridaceae family.
I first saw this species growing at the edge of the King’s Bog in Co Kildare in 2011 when I also photographed it.
If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre