Scientific name: Elodea canadensis Michx.
Common name: Canadian pondweed
Description
Habit: Elongated stems to 3m long, branched, rooted in mud.
Leaves: Submerged, sessile, the lower leaves opposite, the upper leaves in whorls of 3, minutely denticulate, up to 5-17mm long, usually flat, linear or oblong, apex rounded, more or less crowded.
Flowers: Dioecious; spathes tubular, axillary, sessile, 1-flowered; female flowers inconspicuous; petals subequalling the sepals, white to red or pale purple; sepals of female flowers 2-2.7mm across; ovary sessile within the spathe, attenuated into a long, filiform beak; styles 3, usually 2-lobed, free; stamens 9. Male flowers unknown in Ireland.
Habitat: Rivers, canals, ponds and ditches.
Distribution: Frequent in the lowlands, rare in mountain districts.
Native status: Not native
Of conservation interest: No