Myriophyllum pedunculatum

Perennial marsh, aquatic or emergent herb; stems mat-forming, rooting at the nodes, or more or less erect, to 25 cm tall, c. 1 mm diam. Leaves opposite, linear to terete or filiform, with a terminal gland, 4–22 mm long, margins entire or with 1 or 2 lobes. Bracteoles linear to oblong or triangular, 0.4–0.7 mm long, entire or toothed, larger in male flowers; flowers solitary. Male flowers initially sessile, pedicel elongating to 1–4.5 mm; sepals 4, linear to ovate, 0.7–1.5 mm long; petals 4, 1.7–2.5 mm long, yellow to red; stamens 8. Female flowers sessile or shortly pedicellate; sepals filiform to triangular, c. 0.25 mm long, long persistent; petals absent; ovary 4-celled, styles attenuate, reflexed, stigmas white to red. Fruit cubiform, reddish-purple to black; mericarps more or less teardrop-shaped, 1–1.6 mm long including style, attenuate, smooth or warty.