兰氏萍属 lan shi ping shu

Fronds free floating, 1-10 coherent together, shiny green on upper surface, often red on lower surface, outline usually asymmetric, flat or gibbous; 2 basal lateral pouches for reproducing daughter fronds and flowers present, bases of pouches surrounded by small membranous scale covering bases of roots; veins (3-)5-7, splitting from node toward apex, often visible on upper surface. Pigment cells present (visible in dried fronds as brown dots). Roots (1 or)2-7(-12), surrounded by a tubular sheath at base, enclosed by a rounded or pointed cap at apex. Daughter fronds connected to mother frond by thin white stipe. Flower surrounded by a small, utricular, membranous scale with a slit on one side (rarely on two sides); stamens 2, 4-locular. Seeds 1(or 2), ribbed longitudinally.

One species: possibly native to SE Asia and Australia, now invaded to Nearctic, Afrotropical, and Neotropical regions.

Lower Taxon

• Landoltia punctata (G. Meyer) Les & D. J. Crawford