Scientific name: Myriophyllum verticillatum L.
Common name: Whorled Water-milfoil
Description
Habit: A hairless, submerged, aquatic perennial.
Stems: Weak and trailing, aquatic, to 3 m long.
Leaves: Stalkless, without stipules, in whorls of 5; pinnately divided into 8-15 pairs of narrow-linear segments.
Flowers: Small and inconspicuous, mainly unisexual, in clusters forming a loose spike rising above water, with bracteoles; spikes erect in bud; lowest bracts resembling the leaves, upper ones much shorter, pinnately lobed or toothed; sepals inconspicuous or absent; petals 4, yellow, oval, about 2 mm, falling early, often absent from female flowers; ovary superior.
Fruits: 4 1-seeded nutlets.
Habitat: Lakes, ditches.Distribution: Rather rare.
Native status: Native
Of conservation interest: No