青萍（学名：Lemna aequinoctialis）为浮萍科青萍属下的一个种。

Lemna aequinoctialis Welw. (lesser duckweed) is a tiny, floating aquatic plant found in quiet waters in tropical and subtropical regions. Fronds are generally 3-nerved, green, up to 6 mm long. Flowers are 1-ovulate, the small utricular scale open on one side. Seeds have 8–26 ribs.