Aquatic Invasives

Nymphaea mexicana

Nymphaea mexicanaYellow water lily; Geelwaterlelie

Common Name 
Yellow water lily; Geelwaterlelie
Legal Status 
Emerging Weed
NEMBA 1b
Description

Growth form: Perennial, rooted aquatic plant with floating leaves.

Flowers: Pale to bright yellow, 80 – 180 mm across, emergent or floating, open during the day, fragrant. Pointed and star-like petals with greenish-yellow sepals. Flowering period: Nov-Feb.

Fruit/seeds: Green berries which grow underwater.

Leaves: Upper surface of the leaves are green, blotched with brown mostly while leaves are young, lower leaf surface green or pinkish-red with reddish blotches, leaf margins are generally wavy and upturned.

Rhizomes & roots: Stout knobbly rhizomes connected by stolons, roots are long, pale and spongy.

Where does this species come from? 
South America, Mexica - introduced as ornamental pond plant
Why is it a problem? 
It is highly invasive and very difficult to control. It spreads rapidly, quickly covering water surfaces with their large, flat leaves, forming dense infestations which can reduce water movement and displace other submerged aquatic plants and deprive water bodies of oxygen.
Means of reproduction? 
Seedlings or new shoots from its stolons