Myriophyllum verticillatum aka Myriad Leaf

Myriophyllum verticillatum is an aquatic perennial in the Haloragaceae family. Its common names include whorled water milfoil and myriad leaf. It grows across the temperate Northern Hemisphere. Its native range includes Britain and Ireland, Asia, and North America. In the wild, it lives in ponds, lakes, and slow streams. It grows in lowland waters, often where the water is base-rich. Plants For A Future notes that it is uncommon in Britain.

Most of the plant grows beneath the water. Its branched shoots carry leaves in whorls around the stems. Each pinnate leaf divides into fine, hairlike parts. These give the shoots a soft, finely cut look. The RHS describes its foliage as deciduous. Its listed garden height reaches about 0.3 feet [0.1 metres]. Its spread reaches 3.3–4.9 feet [1–1.5 metres]. These garden dimensions describe a broad plant with little height. The RHS gives five to ten years to reach maturity.

In summer, small flower spikes rise above the water surface. The flowers are tiny and dull red. The fine leaves form the main visual feature below water. The raised flower spikes add a small summer detail. The RHS lists this species for wildlife gardens and low-maintenance planting. A pond provides the setting its submerged growth needs. Its broad spread also makes growth control part of care.

Grow it in full sun, using baskets filled with loamy soil. The RHS recommends a water depth of 3.3 feet [1 metre]. It accepts acid, neutral, or alkaline growing conditions. It needs a wet, aquatic site rather than drained garden soil. The RHS rates its UK hardiness as H4. Plants For A Future lists USDA zones 3–7. These ratings come from different regional systems. Cut back the shoots regularly to keep growth within bounds. Root-segment cuttings provide a way to raise more plants.

The RHS reports few usual pest or disease problems. Plants For A Future does not flag it as weedy. Even so, the RHS calls for regular trimming against excess growth. Plants For A Future lists the leaves as edible when cooked. It gives the plant a low food-use rating. That source records no known hazards, rather than a tested safety guarantee. It lists no known medicinal uses or other uses.