Eurasian Watermilfoil
- Usually 12 to 21 leaflet pairs
- Leaves are usually limp when out of the water
- Delicate feather-like leaves with squared-off shape
- Leaflets mostly the same length
- Leaves arranged in whorls (circles) of 3 to 5 around stem
- Long, spaghetti-like stems, sometimes pinkish
- Stems often branch near the surface
Northern Watermilfoil
- Usually 7 to 10 leaflet pairs
- Leaves usually stiff when out of the water
- Rigid feather-like leaves with Christmas tree shape
- Lower leaflets usually quite long
- Leaves arranged in whorls (circles) of 4 to 6 around stem
- Stems usually whitish or whitish green
- Stems don’t typically branch near the surface