Myriophyllum lophatum

Perennial semi-aquatic or emergent herb; stems prostrate, rooting at the nodes, tips erect, 2–3 cm tall, c. 1 mm diam. Leaves opposite, linear, with a terminal gland, 2.5–7 mm long, margins entire. Bracteoles of male flowers oblong to oblanceolate, 1.2–1.8 mm long; bracteoles of female flowers similar 0.5–0.7 mm long; flowers solitary, male and female flowers on same or different shoot. Male flowers initially sessile with the pedicel elongating to 10 mm; sepals absent or 1–4, vestigial, filiform, caducous; petals 4, 1.7–2 mm long, red; stamens 8. Female flowers sessile; sepals and petals absent; ovary 4-celled, styles sessile, stigmas white. Fruit cubiform to cylindric, red to yellowish-brown; mericarps ovoid to cylindric, 0.6–0.8 mm long, truncate, with an irregular dorsal crest and 2 smaller lateral crests. Flowers summer.