Scientific name: Potamogeton coloratus Hornem.
Common name: Fen Pondweed
Description
Habit: Aquatic perennials. Hybrids are rather frequent in this genus.
Leaves: Leaves mostly alternate, some opposite, submerged or floating (rarely aerial on marshy ground), subtending inflorescences, all with membranous sheath or stipules; floating and submerged leaves similar in texture, thin and translucent, with a conspicuous network of opaque veins, often tinged with brownish-red, the uppermost broadly oval, the lower narrower, floating leaves up to 10 x 5cm, ovate to lanceolate, cuneate to subcordate at the base, translucent; submerged leaves up to 18cm, petiolate, similar to the floating leaves but narrower, obtuse, entire; stipules membranous, with well-separated, slender veins, 2-5cm long.
Flowers: In spikes or heads; spike slender, 15-40mm long; peduncle 2-4 times as long; usually borne above the water-surface; perianth of 4 free, greenish segments; carpels usually 4, free; stamens 4, anthers stalkless, attached to the base of the adjoining perianth-segment.
Fruits: Drupes or achenes, 1 or more present, 1.5-1.9mm, greenish, with thick pericarp, soft on outside but with bony inner layer.
Habitat: Shallow, calcareous water in pools and ditches.
Distribution: Frequent in Centre, rather rare elsewhere.
Native status: Native
Of conservation interest: No